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NEW SOUTH WALES.
DEPARTMENT OF PUBLIC INSTRUCTION
TECHNICAL EDUCATION BRANCH.
AN INTRODUCTION
TO THE
GEOLOGY OF NEW SOUTH WALES
C. A. SUSSMILCH, F.G.S.,
LECTURER IN CHARGE OF THE DEPARTMENT OF GEOLOGY AND MINING,
SYDNEY TECHNICAL COLLEGE.
Published by the Authority of the Minister for Public Instruction
in New South Wales.
[COPYRIGHT.]
SYDNEY :
W. A. GULLICK, GOVERNMENT PRINTER.
IQII.
*3910— (a)
8£
m EARTH
SCIENCES
LIBRA*?
To
PROFESSOR T. W. EDGEWORTH DAVID, B.A., D.Sc.
F.R.S., C.M.G.,
TO WHOM WE OWE SO MUCH OF OUR KNOWLEDGE
OF THE GEOLOGY OF NEW SOUTH WALES,
THIS WORK IS DEDICATED.
754
PREFACE.
THIS compilation of our present knowledge of the Geology of
New South Wales has been prepared primarily for the use of
students ; it will also, it is hoped, be of some use to teachers,
mining men, and others. The information has been condensed
as much as possible, so that the size of the book might be kept
within such limits as would enable it to be published at a price
which would be within the reach of all students.
Such a compilation has long been needed, as no connected
account of the Geology of this State has appeared since that
published by the late C. S. Wilkinson in 1882, which has long
been out of print. Many important contributions have been
made to our knowledge since Wilkinson's work was published,
but, scattered as they are through various official and other
publications, some of which have been published abroad,
while others are out of print, the information they contain is
not accessible to the majority of students.
In the preparation of these pages the writer has gathered his
facts from many sources. Full use has been made of the many
excellent monographs, reports, &c., published by the Mines
Department of New South Wales, and from these many of the
geological sections and illustrations of fossils have been taken.
The various geological papers which have appeared from time to
time in the Proceedings of the Royal Society of New South
Wales, the Proceedings of the Linnean Society of New South
Wales, and in the Memoirs of the Australian Museum, have also
been largely drawn upon. The geological workers, whose papers
have been made use of, include, among others, E. C. Andrews,
G. W. Card, J. E. Game, Rev. W. B. Clarke, Professor
T. W. E. David, Hy. Deane, W. S. Dun, R. Etheridge, Junr.,
L. F. Harper, J. B. Jaquet, Dr. H. I. Jensen, E. F. Pittman,
C. S. Wilkinson, Rev. Tennison Woods, and Dr. W. G.
Woolnough.
Even now, notwithstanding the many important additions to
the Geology of New South Wales made during the past twenty-
five years, our knowledge of it is still very incomplete ; many
blanks exist, many problems await solution. The area to be
covered is large, while the workers are few ; so that it will be
many years before anything even approaching a complete
account of the geological history of this State will be possible.
VI
Meanwhile, besides supplying the immediate need for a student's
text-book, it is hoped that this compilation will be serving a
useful purpose in "taking stock " of pur present knowledge — in
showing how much has already been accomplished, how much
still remains to be done.
' Tke classification ,'of the geological formations here used is,
with some slight modifications^ that1 adopted by the Government
Geologist (Mr. E. F. Pittman) in his "Epitome of the Geology < of
New South Wales," published in 1909. The coloured geological
map which accompanied that epitome is here reproduced by the
courtesy of Mr. Pittman, and to him my hearty thanks are also
due for permission to reproduce many of the geological sections
and illustrations of fossils which have appeared in the various
publications issued from his Department. Some of .the fossil
Illustrations have been copied from the Memoirs of the
Australian Museum, and for permission to use these my thanks
are due to the Curator, Mr. R. Etheridge, Junr. To Dr. W. G.
Woolnough my thanks are due for the photograph and section
at Tallong (Figures 3 and 4), and to Dr. D. Mawson for
information regarding the .Broken Hill District. I am much
indebted to Mr. W. ,S. Dun for reading through the lists of
fossils, and for much kind assistance ; and my hearty thanks are
also due to Professor T. W., E. David and Messrs. E. C. Andrews,
G, W. Card, and J. E. Carne for much kindly advice and
assistance.
Sydney Technical College,
October, 1911.
CONTENTS.
CHAPTER I.
Page.
Introduction 1
Order of Succession of the Sedimentary Formations of New South
Wales , 3
CHAPTER II.
PHYSICAL GEOGRAPHY.
The Highlands 5
Distribution, 5 ; the Northern or New England Tableland, 5 ;
the Central Tableland, 6 ; the Southern Tableland, 6.
The Western Plains 6
The Central Western Plateau, 6 ; the Black-soil Plains, 7 ; the
Riverina Plains, 7.
The River Systems :: 7
The Eastern Rivers, 7 ; the Western Rivers, 7.
CHAPTER III.
PRE-CAMBRIAN FORMATIONS.
Barrier District 8
Distribution, 8; the Metamorphic Series, 8 ; the Broken Hill
Lode, 8.
The Cooma-Kosciusko Region 9
CHAPTER IV.
THE CAMBRIAN PERIOD.
Distribution of 10
Barrier District, 10 ; the Cambrian Formation of South Australia,
11 ; the Cambrian Fauna, 11.
CHAPTER V.
THE ORDOVICIAN PERIOD.
Occurrence and Distribution of Ordovician Strata 13
Counties of Auckland and Wellington, 14 ; Tallong, 15 ;
Lyndhurst Goldfield, 15 ; Cadia District, 15 ; Parkes-Forbes
District, 16.
Ordovician Life 16
Summary of the Ordovician Period 17
CHAPTER VI.
THE SILURIAN PERIOD.
Nature of the Silurian Strata— their distribution 19
Yass-Bowning District, 20 ; Boambola, 22 ; Jenolan District, 22 ;
Bathurst District, 24 ; Orange-Molong District, 25 ; Parkes-
Forbes District, 26 ; the Western Areas, 26.
Economic Aspects of the Silurian Formations 28
Silurian Life... 28
Summary of the Silurian Period '.' 32
Vlll
CHAPTER VII.
THE DEVONIAN PERIOD.
Page.
Distribution of the Devonian Formation 34
The Lower Devonian or Murrumbidgean Series 35
Nature of the Strata, 35 ; the Murrumbidgee Beds, 36 ; the
Volcanic Stage. 36 ; the Limestone Stage, 36 ; the Tuffaceous
Shale Stage, 37 ; Comparison with Victorian Devonian
Rocks, 37 ; the Tamworth Beds, 37 ; Bingera and Barraba
Districts, 38.
Lower Devonian Life 39
The Marine Fauna, 39 ; the Fossil Flora, 42 ; Comparison of the
Murrumbidgee and Tamworth Faunas, 42.
The Upper Devonian or Lambian Series 43
The Mount Lambie Beds, 43 ; the Molong-Canobolas Beds, 44 ;
the Parkes-Forbes Beds, 45 ; the Western Areas, 45 ;
South-eastern Districts, 45.
Upper Devonian Life 48
The Marine Fauna, 48 ; the Devonian Flora, 49.
Summary of the Devonian Period 49
Close of the Devonian Period — the Kanimbia Epoch 51
CHAPTER VIII.
THE CARBONIFEROUS PERIOD.
Distribution of the Carboniferous Formation 53
Lower Carboniferous Formation 53
Upper do do 54
Hunter River District, 54 ; Western New England, 55.
Carboniferous Life ; 56
The Carboniferous Flora, 56 ; the Carboniferous Fauna, 57.
Summary of the Carboniferous Period 59"
CHAPTER IX.
THE PERMO-CARBONIFEROTJS PERIOD.
Distribution of and subdivision of the Permo- Carboniferous Forma-
tion 60
The Lower Marine Series 61
Hunter River District, 61 ; the Northern Rivers District, 63 ;
Emmaville District, 63.
The Lower Coal-measure Series 63
Hunter River District, 63 ; New England Tableland, 66 ; Illa-
warra District, 67.
The Upper Marine Series 67
Hunter River District, 6/ ; the Lithgow-Capertee District, 68 ;
the South-western Coal-field, 69 ; the Illawarra District, 69 ;
Gerringong Fossils, 71 ; Kiama Volcanic Series, 72.
The Tomago and Denapsey Series (Middle Coal Measures) 75
The Upper Coal Measures : 76
Newcastle Coal Measures, 77 ; Origin of the Coal, 79 ; Rix's
Creek Coal-field, 81 ; Curlewis-Gunnedah Coal-field, 81 ; the
Murrurundi District, 81 ; the Western Coal-field, 83 ; the
South-western Coal-field, 83 ; the Southern or Illawarra
Coal-field, 84.
IX
CHAPTER X.
THE PERMO-CARBONIFEROUS PERIOD — continued.
Page,
Permo-Carbonif erous Life 85
The Marine Fauna, 85 ; the Terrestrial Flora and Fauna, 90 ;
Comparison of the Carboniferous, Permo-Carboniferous, and
Triassic Floras, 92 ; the Land Animals, 93.
Economic Importance of the Permo-Carboniferous Formation 94
The Coal — Quality and available supplies, 94 ; Analyses, 94 ;
Kerosene Shale, 95 ; Analyses, 95 ; Clays, 96.
The Permo-Carboniferous Glaciation 96
Cause of the Glaciation, 98.
Summary of the Permo-Carbohif erous Period 99
CHAPTER XI.
THE TRIASSIC AND JURASSIC PERIODS.
Nature of and subdivisions of the Trias- Jura Formations 103
The Hawkesbury Series 104
The Narrabeen Stage, 104 ; the Hawkesbury-Sandstone Stage,
107 ; the Wianamatta Stage, 111 ; Relation of the Hawkes-
bury Series to the Upper Coal Measures, 112,
Life of the Triassic Period (Hawkesbury Series) 113
The Fossil Plants, 113 ; the Fossil Fauna, 113.
The Clarence Series 116
The Artesian Series 118
The Talbragar Series 119
Correlation of the Hawkesbury, Clarence, Artesian, and Talbragar
Freshwater Beds 119
Summary of the Triassic and Jurassic Periods 121
CHAPTER XII.
THE CRETACEOUS PERIOD.
Distribution of and subdivision of the Cretaceous Formation 123
The Rolling Downs Formation, 123 ; the Desert Sandstone
Foi-mation, 124.
Cretaceous Life 125
Summary of the Cretaceous Period 12S
CHAPTER XIII.
THE TERTIARY PERIOD.
Nature of the Tertiary Formations 130
The Marine Strata 130
The Fluviatile Deposits 132
The Lower Tertiary Leads, 132 ; the Kiandra Lead, 132 ; the
Bathurst Lead,"l34 ; Upper Tertiary Leads, 134 ; Vegetable
Creek Leads, 134 ; the Parkes-Forbes Leads, 135 ; the
Gulgong Leads, 136 ; the Forest Reefs Leads, 137.
The Diatomaceous Earth Deposits 137
The Volcanic Deposits 137
The Older Basalts, 138 ; the Newer Basalts, 138 ; the Alkaline
Lavas and Tuffs, 139
The Tertiary Flora 139
The Tertiary Fauna 140
The Development of the Present Topography 143
Summary of the Cretaceous Period 146
Close of the Tertiary Period — Kosciusko Epoch, 148.
*3910-(O
CHAPTER XIV.
THE PLEISTOCENE PERIOD.
Page.
Results of the Kosciusko Uplift 149
Effect upon the Climate, 149 ; Effect upon the Flora and Fauna,
149.
Pleistocene Deposits 151
The Glacial Epoch 151
Recent Earth Movements .. 153
CHAPTER XV.
THE IGNEOUS ROCKS OF NEW SOUTH WALES.
The Intrusive Rocks 155
Palaeozoic Intrusives, 155 ; Cainozoic Intrusions, 159.
The Volcanic Rocks 161
Cambrian, 161 ; Ordovician, 161 ; Silurian, 161 ; Devonian, 161 ;
Carboniferous, 162; Permo-Carboniferous, 162; theMesozoic
Era, 162 ; Cainozoic Era, 163.
Summary of the Igneous Rocks 164
Tables of Analyses 165
ILLUSTRATIONS.
Fig. Page.
1. Section of Lower Cambrian Beds, South Australia 11
2. Archaeocyathinse Limestone, Beltana, South Australia 12
3. Ordovician Strata, Shoalhaven River, near Tallong 13
4. Section of Ordovician and'Silurian Strata, Tallong 14
5. Section of (?) Ordovician Strata, Cadia 15
6. Ordovician Graptolites 17
7. Silurian Limestone, Hatton's Corner, Yass 20
8. Silurian Clay stones, Jenolan 23
9. Section, Big-Nugget Hill, Hargraves 24
10. Succession of Strata, Oaky Creek, near Orange 25
11. Characteristic Silurian Corals 27
12. A Silurian Bryozoan 29
13. Characteristic Silurian Brachiopods 30
14. Weathered Specimen of Pentamtrus 30
15. Silurian Trilobites 31
16. Lower Devonian Beds, Taemas, Murrumbidgee River 34
17. Section of Silurian and Lower Devonian Strata, Murrumbidgee
River, near Yass 35
18. Lower Devonian Corals and Sponges' 39
1 9. Lower Devonian Molluscoidea and Mollusca 41
20. Section from Mount Lambie to Rydal 42
21. Upper Devonian Strata, Mount Lambie 43
22. Succession of Silurian and Devonian Strata, Gap Creek, Orange
District 44
23. Section of Siluriaa and Devonian Strata, Gap Creek, Orange
District 45
23A. Inclined Devonian (^uartzites, Gap Creek 46
24. Upper Devonian Fossils 47
25. Section of Carboniferous Strata, Clarence Town 54
26. Carboniferous Plants 56
27. A Carboniferous Trilobite 57
28. Carboniferous Brachiopods 58
29. Map of New South Wales, showing the area covered by Upper
Permo-Carboniferous Strata Between pages 60 and 61
30. Glacial Erratic, Branxton, New South Wales 62
31. Section of Permo-Carboniferous Strata, near Raymond Terrace 64
32. Section across Drake Gold-field, New England 64
33. Section across the Lochinvar Anticline 65
34. Section of the Ashford Coal Basin 65
35. Section from Clyde River to Jervis Bay Bore 70
36. Diagramatic Section of the Volcanic Series, Kiama District ... 72
37. Basalt Flow, Westley Park, Kiama 73
Xll
Fig. Page.
38. Columnar Basalt, Kiama 74
39. Cliff Section, Moon Island, Newcastle 78
40. Section of Upper Coal Measures, Swansea, Newcastle 79
41 . Cliff Section of Upper Coal Measures, Newcastle 80
42. Section showing Faulting of the Upper Coal Measures 82
43. Permo-Carbonif erous Corals and Bryozoa 85
44. Permo-Carboniferous Echinodermata 87
45. Permo-Carboniferous Brachiopods 88
46. Permo-Carboniferous Mollusca 89
47. Permo-Carboniferous Plants 90
48. Permo-Carboniferous Plants 91
49. Permo-Carboniferous Amphibian 93
50. Narrabeen Beds, near Newport 103
51. Ideal Section, Mount Lambie to the Coast 105
52. Sketch-section, Jenolan to Mount Victoria 107
53. Triassic Sandstones, Valley of the Waters, Bme Mountains ... 108
54. Current-bedding in Hawkesbury Sandstone, Bondi 109
55. Prismatic Sandstone, Bondi 110
56. Section of Triassic and Permo-Carboniferous Strata, JSilalong 112
57. Triassic Plant, Thinnfeldia odontopteroides 113
58. A Triassic Fish, Pleuracanthus 115
59. New South Wales Triassic Fish 116
60. Trias- Jura Plants 117
61 . Map — Triassic Between pages 118 and 119
62. Map— Cretaceous Between pages 122 and 123
63. Section from Inverell to Mount Brown of the Cretaceous and
Triassic Basin 125
64. Cretaceous Pelecypoda 127
65. Cretaceous Cephalopoda ; 128
66. Tertiary Basalt Flow, Guy Fawkes, New England 131
67. Map of South-eastern New South Wales, showing probable
area of Eocene Sea 132
68. Section of the Kiandra Lead 133
69. Section of one of the Deep Leads at Forbes 135
70. Section across the Bald Hills, Bathurst 138
71. Diprotodon A ustralis (restored) 141
72. Skull of Diprotodon Australis 142
73. Skull of Thylacoleo carnifex 142
74. The Great Eastralian Peneplain, near Yass 145
75. The Blue Lake, Kosciusko Tableland 150
76. Lake Cootapatamba 152
77. Section of the Raised Beach at Largs 153
78. Section in New England, showing the various Plutonic Intru-
sions . . 157
79. Granite, Baker's Creek, New England 158.
CHAPTER T.
INTRODUCTION.
THE earliest connected account of the Geology of New South
Wales is that written by the late Rev. W. B. Clarke, and
published by him in 1867, entitled " Remarks on the Sedimentary
Formations of New South Wales "; later editions of this work
appeared in 1870, 1875, and 1878. This great worker, the
pioneer of the geologists of this State, laboured for many years,
practically singlehanded. in a thinly-populated area of vast
extent, and established the succession of the sedimentary forma-
tions of New South Wales. Upon the foundations so ably laid
by him the superstructure of our present knowledge of its
geological history has been erected. Considering the adverse
circumstances under which he laboured, it is surprising how well
these foundations have stood the test of time, and they stand
to-day as an enduring record of his great ability and the patient
care with which he applied himself to his work.
In 1882 the late C. S. Wilkinson, F.G.S , F.L.S., then
Government Geologist, published his " Notes on the Geology of
New South Wales "; in this he summarised the information then
available. He, too, was an able pioneer and great worker, who
thought nothing of making long journeys through the sparsely-
settled interior, where travelling was of the roughest and means
of communication few. He added notably to our knowledge, and
was a worthy successor to Clarke.
Since 1882 many able geologists have added largely to our
store of knowledge, but, except for an epitome published in 1909
by Mr. E. F. Pittman, Government Geologist, no connected
account of the geology of this State has since appeared.
The main features of the geological history of New South Wales
are now well established, but much additional field-work must
be undertaken before anything like a complete record is
available. This applies particularly to the pre Cambrian and
Lower Palaeozoic periods, our knowledge of which is still very
incomplete.
3910— A
The order of succession of the sedimentary formations of New
South Wales is given in tabular form on pages 3 and 4. An
examination of this will show that nearly all the main sub-
divisions of the geological record of the Northern Hemisphere are
represented, and that the same names are in general used for
them. It must, however, be remembered that it is not by any
means certain that formations which carry similar names in
Australia and Europe were actually contemporaneous ; in fact,
some Australian geologists go so far as to suggest that purely
local names should be used for the subdivisions of the great eras
in Australia.
Pre-Cambrian formations appear to be but poorly represented,
and occur over but limited areas, while the Cambrian has an
even more limited development. The other divisions of the
Lower Palaeozoic era, viz., the Ordovician, Silurian, and
Devonian, occur, however, more or less over the whole State,
although concealed to a considerable extent in some regions by
younger formations. The Upper Palaeozoic formations are less
widely distributed, being confined to the central and northern
tableland areas. The Mesozoic era is represented by fresh- water
Trias and Trias-Jura strata and by Cretaceous marine strata, but
their development is in nowise comparable with that of the
Palaeozoic formations either in thickness or extent. Tertiary
formations are still more poorly represented, marine strata are
practically absent, while fresh- water deposits are limited to those
occurring along Tertiary stream channels ; Tertiary lava flows are,
however, abundant and widespread. The direct geological
records of the Tertiary history are, in fact, so scanty that, were
it not for the evidence provided by a study of the development
of its physiography, our knowledge would be limited indeed.
Fortunately, the topography has recorded a very legible and
interesting history, which will be fully dealt with in a later
chapter.
Orogenic earth movements are recorded for the pre-Cambrian
and Palaeozoic eras only ; the most important crustal movements
of this class appear to have taken place (1) at the close of the
pre-Cambrian ; (2) at the close of the Ordovician ; (3) at the
close of the Devonian periods ; and in addition, (4) at the close
of the Palaeozoic era in the north-eastern part of the State. The
crustal movements of the Mesozoic and Cainozoic eras were of
the epeirogenic type in which vertical uplift was the dominant
feature.
The succession of animals and plants, has been, on the
whole, essentially similar to that of other parts of the world ;
there are, however, some striking differences, particularly in
the life of the land. The marine faunas of the various sub-
divisions of the Palaeozoic era and of the Cretaceous period,
resemble fairly closely those of the northern hemisphere, some of
the species even being identical. In its terrestrial faunas .
however, New South Wales, in common with the rest of Australia ,
shows some remarkable features. That extraordinary group of
terrestrial reptiles which dominated the Mesozoic land life of
Europe and North America, is conspicuously absent, the only
land vertebrates known to have lived during this era being fish
and amphibia, and many of these were akin to Palaeozoic types
of the Northern Hemisphere. Again, placerital mammals, either
as fossils or as indigenous living animals, are entirely absent from
Australia ; on the other hand the non-placental mammals (Mono-
tremes and Marsupials), both during the Tertiary period and at
the present day, developed on a scale unknown in any other part
of the world.
The fossil floras, too, possessed characters of their own ; the
Permo-Carhoniferous flora (Glossopteris flora) for example, while
identical with that of the same period in India and South Africa,
has no counterpart in the Carboniferous or Permian floras of
Europe and North America.
The mineral wealth of New South Wales is considerable, the
output for the year 1910 being valued at about £8,700,000
sterling, while the total production to date exceeds £208,000,000
in value. The more important substances mined include coal,
copper, gold, silver, lead, zinc, tin, and precious stones.
ORDER OF SUCCESSION OF THE SEDIMENTARY FORMATIONS
OF NEW SOUTH WALES.
( Recent : — Auriferous and stanniferous soils
Post Tert' • < and alluvial deposits in the beds of
I existing rivers. Beach deposits.
( Pleistocene : — Glacial deposits of the Kosci-
usko tableland, deep and shal-
low alluvial leads, containing
CAINOZOIC j tin, gold, and gemstones. Al-
ERA. j luvial deposits of the western
plains.
( Upper Tertiary • — Alkaline rocks of the
Canoblas, War ruin bungle
& Nandewar Mountains.
I Tertiary. The newer basalts.
Alluvial leads under the
I newer basalts.
(.Lower Tertiary : — The older basalts.
Alluvial leads under the
older basalts.
Marine strata of the
south-western part of the
tate.
f Cretaceous. ( Upper Cretaceous:— Desert sandstone forma-
Ition.
[Lower Cretaceous: — Rolling-downs forma-
MESOZOIC j tion.
ERA. Trias-Jura. Clarence series, Artesian series, Talbragar
beds.
C Wianamatta shales.
I Triassic. Hawkesbury series 5 Hawkesbury sandstone.
(.Narrabeen beds.
( f Upper coal measures.
| Dempsey series.
Permo- j Middle or Tomago coal measures.
Carboniferous, j Upper Marine series.
| Lower or Greta coal measures.
I Lower Marine series.
C Upper Carboniferous — Rhacopteris beds and
Carboniferous. -| associated Marine beds.
Lower Carboniferous.
Upper Devonian (Lambian), Mount Lambie,
Molong and Yalwal beds.
Lower Devonian (Murrumbidgean), Murrum-
bidgee beds and Tarn worth beds.
Limestone and claystones at Yass, Molong,
Orange, Jenolan, Wellington, &c.
Graptolite slates of Cadia, Tomingley,
Mandurama, Tallong, Berridale, &c.
Glacial beds, limestone, &c., of the Barrier
district.
PALAEOZOIC
ERA.
Devonian.
Silurian.
Ordovician.
Cambrian.
PROTEROZOIC^
AND
ARCHEOZOIC
Pre-Cambria'tt.
Metamorphic series of the Broken Hill and
Cooma districts.
ERAS. )
CHAPTER II.
PHYSICAL GEOGRAPHY.
NEW SOUTH WALES, from a geographical point of view, consists
of two portions — (a) The Highlands; (6) The Western Plains.
(a) THE HIGHLANDS.
These consist of a series of tablelands occupying the whole of
the eastern part of the State, and extending from the coast inland
for a distance of from 150 to 200 miles. They thus form a broad
belt parallel to the coast, and are co-extensive with the high lands
of Victoria and Queensland. These tablelands resulted from the
uplift of a peneplain at the close of the Tertiary period to
altitudes varying from a few hundred up to 6,000 feet, but
averaging about 3,000 feet. This differential uplift was accom-
panied by faulting and warping, as a result of which the plateau
region now consists of a series of more or less rectangular blocks
(fault-blocks) separated from one another in many cases by abrupt
differences of elevation. This tableland region in its central
portions is more or less flat-topped, but its margins are flexed
downwards towards the coast on the one hand and towards the
western plains on the other. On both its eastern and western
margins the plateau region has suffered considerable dissection
by stream action since its uplift. Extensive flood plains have
been developed along the lower courses of the eastern rivers, and
these are sometimes referred to as coastal plains ; similarly where
the western streams approach the western plains the tablelands
have been much dissected, and extensive alluvia tion marks the
entry of these streams on to the plains.
The highlands may, for convenience, be divided into three
portions : —
1. The Northern or New England Tableland.
2. The Central Tableland.
3. The Southern or Monaro Tableland.
1. The Northern or Neiv England Tableland. — This extends
from the Queensland border southwards to the Hunter River
district; here, the Hunter River, cutting its valley westward into
the main divide, and the Peel River heading eastward, have
nearly breached the divide, a low ridge only, remaining as a
connection between the northern and central tablelands. This
breaching of the high lands at this point may be partly due to
unequal uplift accompanied by faulting. The northern tableland
is built up, very largely, of Palaeozoic formations, but in the
north-eastern corner, and along the western margin, these rocks
are overlain by Trias-Jura fresh-water beds. Tertiary basalt flows
occur over considerable areas. The genera] altitude of this
tableland is about 3, 300 feet, but some of the fault-blocks, such as
those at Guy Fawkes and Guyra, rise to altitudes of from 4,000
to 5,000 feet.
2. The Central Tableland. — The northern margin of this section
has already been referred to. It is bounded on the south by the
Yass tableland, a relatively low fault-block (1,700 to 2,000 feet
in altitude) which lies between it and the Monaro tableland.
The altitude of the central tableland varies ; the Bowral-Moss
Vale portion has an altitude of about 2,000 feet, the Wombeyan
portion about 3,000 feet, the Blue Mountain portion varies from
700 to 3,600 feet with a decided warp eastwards, the Orange-
Blayney portion about 3,000 feet, while the Sydney Senkungsfeld
in its lowest portion is not much above sea-level. The western
and south-western parts of this tableland are built up of Palaeo-
zoic rocks, but its eastern and northern portions are occupied
by the Permo-Carboniferous-Triassic basin.
3. The Southern Tableland. — This occupies the south-eastern
part of the State, and includes the highest land in Australia. It
is a composite tableland, consisting of a group of fault-blocks
ranging from 2,000 to 7,000 feet in altitude, and separated from
one another by great fault escarpments. Some of the lower
blocks are sandwiched in between higher blocks in such a way as
to form typical " rift valleys " or senkungsf elder. The whole of
this region is occupied by pre-Cambrian and Lower Palaeozoic
rocks, except for a capping of Permo-Carboniferous strata over a
limited area in its north-eastern portion. Extensive Tertiary
basalt-flows cap the tableland in many places.
(b] THE WESTERN PLAINS.
These extend from the western edge of the eastern highlands
to the South Australian border ; they consist partly of low flat-
topped plateaux and partly of alluvial plains, and nowhere have
an altitude greater than 1,000 feet. Occasional isolated hills
rise above the level of the plains, but these are few and far be-
tween. The low plauteau portion forms a broad belt extending
from the western edge of the central tableland in a westerly
and north-westerly direction to the Darling River, and from
thence to the South Australian border ; its surface is a peneplain
cut out of Lower Palaeozoic strata. For this area the term
central- western tableland may be used in order to distinguish
between it and the alluvial plains to the north and south. The
general altitude of its surface ranges from 600 to 900 feet. To
the north of this lie the " Black-soil Plains," which consist of
alluvium deposited by the Darling River, and its tributaries
during flood-time ; these alluvial deposits overlie the Cretaceous
and Trias-Jura strata which form the artesian basin of New
South Wales. South of the low plateau belt and along the lower
courses of the Murray, Murrumbidgee, Lachlan, and Darling
Rivers, lie the Riverina Plains : here also the surface is occupied
by alluvial deposits, the waste of the southern tablelands brought
down and deposited by rivers during floods. These alluviums
overlie Lower Palaeozoic strata, except in the south-western corner,
where they overlie Tertiary marine beds. The rainfall over the
western plains is small, varying from 20 inches to less than 10
inches ; over the tablelands, on the other hand, the rainfall ranges
from 20 to 70 inches per annum.
(c) THE RIVER SYSTEMS.
As the main divide of New South Wales runs approximately
north and south, the rivers fall naturally into two groups —
(1) the eastern rivers ; (2) the western rivers ; and as the main
divide is relatively near the eastern coast, the eastern rivers are
correspondingly short, while the western streams are much longer.
1. The Eastern Rivers. — As these have relatively short courses
and a high grade they are, for the most part, rapidly flowing
streams, subject to severe floods. Some of them, like the Hunter
River, flow in more or less direct courses to the sea ; others, like
the Hawkesbury River, have their main course parallel to the
coast for 100 miles or more. In nearly all cases there is abundant
evidence that these are revived or rejuvenated streams, and
existed before the uplift which produced the existing highlands
took place. Throughout the greater part of their courses they
are entrenched in deep canyons.
2. The Western Rivers. — These may be divided into two
groups, a northern one, which includes the Upper Darling River
and ,its tributaries, and a southern group, the Murray and its
tributaries, the Murrumbidgee and Lachlan Rivers. Many of
the northern group, such as the Macquarie, Bogari, &c., flow in a
general north-westerly direction until they join the Darling River.
They probably originated during the Cretaceous Period and flowed
then as individual streams to the south-eastern margin of the
Cretaceous sea. Some of these tributaries of the Darling, for
example the Macquarie, fail to reach it, except in flood -time, but
die away in marshes and swamps. The Murray River, like its
tributaries the Murrumbidgee and Lachlan Rivers, flows in a
general westerly direction to the South Australian border, where
it suddenly turns southward and empties into the Southern Ocean.
CHAPTER III.
PRE-CAMBRIAN FORMATIONS.
VERY little is known at present of the occurrence of pre-Cambrian
rocks in New South Wales, and as the greater part of the State
has now been mapped in some detail, it is fairly certain that the
areas over which such rocks might occur must be limited in
extent. There are two districts in which pre-Cambrian rocks are
definitely known to occur, viz., the Barrier district and the
Cooma-Kosciusko district.
The Barrier District. — This is in the western part of New
South Wales, adjacent to the South Australian border, with the
town of Broken Hill as its chief centre. The rich silver lead-zinc
deposits of this region have made it world famous. The oldest
undoubted sedimentary strata occurring here are of Cambrian
age, and will be described in the next chapter ; associated with
these there is an older metamorphic series of undoubted
pre-Cambrian age. This series includes gneisses, schists, quartz-
garnet rocks, and amphibolites ; garnet is a common constituent
of many of these rocks, while the schists include mica-schists,
sillimanite-schists, talc-schists, and chlorite-schists. The origin
of this metamorphic series has not yet been satisfactorily
determined, but the balance of evidence appears to favour the
view that many of the rocks represent highly altered sedimen-
taries. They outcrop over an area about 20 miles long, in a
north and south direction, and about 30 miles wide, and are
unconformable with the Cambrian strata above referred to. It
has been suggested that the amphibolites are intrusive sills
forced along the bedding planes of the sedimentary rocks before
they were metamorphosed, but the description of their occurrence
suggests that they may be inters bra tified with the schists. If
this view is correct, they possibly represent highly metamorphosed
basic lavas and tuffs.
Associated with this metamorphic series there occurs one of
the richest of the world's ore deposits, some idea of the value of
which may be gathered from the fact that during the twenty-five
years which have elapsed since the mining was first started
£60,000,000 worth of metals hare been produced, and £13,000,000
have been paid in bonuses and dividends. This deposit is being
worked for a distance of 3 miles along its strike, and to a depth
of 1,600 feet below the outcrop, and at some places to a width of
9
upwards of 400 feet. The true origin of this mammoth ore
deposit is still in dispute ; some regard it as being a saddle-reef,
analogous to those of the Bendigo Gold-field, while others regard
it as having been produced by the metasomatic replacement
of the country rock along a zone of shearing and crushing
(shear-zone).
The original sulphide ore consists of an intimate mixture of
argentiferous-galena and zinc-blende, with smaller amounts of
quartz, garnet, felspar, rhodonite, pyrite, and chalcopyrite ; it
contains from 5 to 36 oz. of silver, from 5 to 50 per cent, of lead,
and from 14 to 30 per cent, of zinc, and from 2 to 3 dwt. of gold
per ton. The oxidised zone was very rich in carbonate of lead,
chloro-bromides of silver, and native silver. The value of this
ore ranged up to 300 oz. of silver and 60 per cent, of lead per ton.
Cooma-Kosciusko Region. — In the neighbourhood of Cooma
there occurs an extensive series of metamorphic rocks, including
gneiss, mica-schists, phyllites, and amphibolite ; in the same area
there also occurs the fossiliferous Ordovician strata referred to on
page 15. The field relations of these two series of strata have
not yet been investigated, but as the latter have suffered very
little metamorphism, while the former are strongly metamorphosed,
it seems fairly certain that the former must be considerably
older than the Ordovician beds. The metamorphic series, in
their lithological characters, much resemble the pre-Cambriaii
formations of other parts of Australia, and may, therefore, be
provisionally classed with them. Near Cooma the gneisses
contain numerous veins of pegmatite, in some of which the
mineral tourmaline is abundant ; they have also associated with
them irregular masses of amphobolite. The schists and phyllites
are very much contorted, and show every evidence of having
been subjected to extreme metamorphic influences.
Somewhat similar gneisses and phyllites occur on the Kosciusko
Tableland.
CHAPTER IV.
CAMBRIAN PERIOD.
No strata containing Cambrian fossils have yet been found in
New South Wales, but Mr. D. Mawson, D.Sc., has recently shown
that certain strata in the Barrier District are lithologically the
same as the Cambrian strata of South Australia, and are con-
tinuous with them. They outcrop at Tarrawingie, about 20 miles
from Broken Hill, and include slates, quartzites, limestone,
dolomitic-limestones, and glacial boulder-beds. This series is
unconformable with the pre-Cambrian metamorphic series of
Broken Hill. The glacial boulder-beds consist of a fine-grained
quartzitic matrix (sometimes argillaceous), in which are embedded
boulders of quartzite, schist, and slate. As no detailed descrip-
tion of the New South Wales Cambrian strata is yet available, a
description of their equivalents in South Australia will not be
out of place.
A generalised section of these Cambrian strata (as drawn by
the Rev. W. Howchin, F.G.S.) is given in Fig. 1. They will be
seen to consist of conglomerates, limestones, quartzite, slates, and
glacial beds, the whole series resting unconformably upon a pre-
Cambrian metamorphic series. The beds described as having a
glacial origin consist mainly of unstratified, indurated muds tone,
more or less gritty, and carrying angular, subangular, arid
rounded boulders, which are irregularly distributed through the
mass ; these boulders range up to 1 1 feet in diameter. Most of
the large erratics consist of quartzite, but granite, gneiss,
porphyry, and schist erratics also occur ; many of these boulders
are ice scratched and faceted. These boulder-beds are regularly
interstratified with the Cambrian sediments, and do not rest upon
a glaciated land surface ; they are, therefore, not typical moraine-
deposits. Nevertheless, much of the material in these beds has
undoubtedly had its origin in terrestrial glaciers, and was trans-
ported to its present position by floating ice. The position of the
Cambrian land which supported the glaciers is not definitely
known, but appears to have been to the south-west of the present
glacial beds. The glaciers must have reached sea-level, and, as
happens in Antarctica to-day, large masses of ice must have broken
away from time to time, and floated northwards across the
Cambrian sea ; as this ice melted, its load of morainic material
would be strewn over the sea-bottom.
11
The limestone beds are numerous,
and range up to several hundreds
of feet in thickness ; some of them
are dolomitic in composition. Only
two of them are known to con-
tain fossils, and, of these, the
most important is that containing
Arcliceocyathince. These organisms,
although not true corals, built
extensive reefs in the Cambrian
seas, not unlike the coral-reefs of
the present day. The same lime-
stone contains numerous other fossil
invertebrates, such as Sponges, Tri-
lobites, Brachiopods, Gasteropods,
and Pteropods. The other fossil-
iferous horizon occurs about 1,000
feet vertically above the Arcbseocy-
athina? limestone, and is strati-
graphically above the glacial beds ;
it contains Trilobites, Brachiopods,
and Pteropods. As already men-
tioned, no fossils haxe yet been
obtained from the Cambrian strata
in New South Wales, but as it is
probable that life in the Cambrian
seas of New South Wales was
essentially the same as in South
Australia, the following list of
Cambrian fossils from the neigh-
bouring part of the latter State
may be taken as representing the
Cambrian fauna : —
Archaeocyathinse. — Archcvocyatkus,
Coscinocyathus.
Porifera. — Hyalostelia.
Brachiopoda. — Orthisina, Orthis (?},
Obolella.
Pelecypoda. — Ambonychia.
Gasteropoda. — Stenotheca, Ptatyce-
ras, Ophileta,
Pteropoda. — SaltereUa, Hyolithes.
Tril obita. — Olenelhis, Microdiscus,
Conocephalites, Ptychoparia,
Dolichomptopus.
Crustacea (Ostracods). — Leperditia.
II-
!il
i ii
5 S.I
v S'
^ „••§,
P3 a «
c »
1 1;
I
J "I
| "I
*o ^
§ |J
1 ||
•3,
I 1
e« ™
cf '"S
S b°
12
THE ARCH^EOCYATHIN^E. — These anomalous organisms have the
outward form of Sponges, but in their more detailed structures
they resemble corals. (See Fig. 2.) They have been referred by
different palaeontologists to the Algse, the Sponges, and to the
Corals ; it has also been suggested that they are the ancestors of
both the Corals and the calcareous Sponges. Whatever their
true nature, they flourished in enormous numbers in the Cambrian
seas, occupying in importance the position later taken by the
reef -building Corals.
Fig. 2.
Archseocyathinse Limestone, from Ajax Hill, Beltana, South Australia.
An etched specimen showing the fossils in relief. (After Taylor.)
BRACHIOPODS. — These belong to small primitive types.
MOLLUSCA. — The Gasteropods and Pteropods are most in
evidence ; the former belong chiefly to the primitive uncoiled
conical types (capulids).
CRUSTACEA. — Tribolites were abundant, and were the most dis-
tinctive and highly organized denizens of the Cambrian sea; of the
genera listed above, Olenellus is perhaps the most characteristic.
Small Ostracods, which had their bodies protected by valve-like
shells, resembling those of the bivalve molluscs, also occurred in
considerable numbers.
CHAPTER V.
THE ORDOVICIAN PERIOD.
THE occurrence of Ordovician strata in New South Wales was
unknown as recently as 1896, when Mr. J. E. Carne discovered
[Photo, by W. G. Woolnough, D.Sc.]
Fig. 3.
Ordovician Strata, Shoalhaven Kiver, near Tallong, New South Wales.
Ordovician graptolites in the
Counties of Auckland and
Wellesley, near the Victorian
border. Since then similar
graptolite-bearing strata have
been found at many widely
separate localities on the
southern and central table-
lands, as far north as Toming-
ley. The known occurrences
apparently lie on several well-
defined north and south axial-
lines.
The repeated discovery of
Ordovician graptolites in
strata, previously believed to
be of Silurian age, makes it
probable that they may be
found in many other parts of
the State, and thus very much
extend the known Ordovician
areas. The lithological charac-
ters of some of the so-called
Silurian strata presents con-
siderable similarity, so that
the determination of the age
of either strata on any other
than a palseontological basis
is practically impossible.
Counties of Auckland and
Wellesley. — The strata here
consist of carbonaceous shales,
clay stones, sandstones, and
schists striking nearly north
and south, and outcropping at
intervals along the southern
border of New South Wales
from Cape Howe to the head-
waters of the Murray River.
These beds are, no doubt, an
extension of the well-known
Ordovician strata of the
adjoining State of Victoria.
Graptolites occur in abun-
dance in the carbonaceous
shales. Auriferous quartz
15
reefs intersect the strata in many places and have been mined
to some extent. Similar graptolite beds occur at Berridale, and
also in the neighbourhood of Cooma ; at the former locality
radiolaria are also found. *
Tallong. — A thick series of Ordovician strata outcrops on the
Razorback, a *pur between Barber's Creek and the Shoalhaven
River. (Fig. 3.) They consist of carbonaceous shales, slates, and
quartzites, all of which are intensely folded and crumpled. The
first-named contains numerous well-preserved graptolites. Silurian
strata can here be seen resting upon the Ordovician beds, and
are separated from them by a well-marked unconformity. (Fig. 4.)
The mineral deposits at Tolwong, some few miles to the south,
occur in strata of similar age.
SECTION ON LINE AB ISlXiSZZx ^
Horizontal Scule 9 . ? . * Chains *nd c/*y ste/fs,
Vertical Scale 9 . *9° . *P Feet FallB v-, ^ , - . ^ , rT^gf
, , * i* '^ ' ^ ^ n ?J~ ^~ -^ f~*
S- ^'~ -^ v*~^><c iTT~isCji^>*^
F.IU
^^^^^^^:f^'<^
^^T^^JT^^^
^^^J-V; : ',- :->W-,-,^ ;v -;;,; , -;, - : , -
Datum Height above Sea Level 2600 Feet (AbouO
«^«r
Fig. 5.
Section of (?) Ordovician Strata, Cadia, New South Wales. (Jaquet.)
Lyndhurst Gold-jield. — At Mandurama the Ordovician formation
consists of claystones with interbedded tuffs and thin bands of
radiolarian limestones, the whole occurrence bearing a remarkable
resemblance to the radiolarian beds of the Tamworth district.
The Tamworth beds are, however, believed to be of Lower
Devonian age. The Mandurama claystones contain graptolites,
Brac-hiopods (Obolella), and doubtful Trilo bites (? Agnostus).
The whole series has been intruded by dykes and sills of diorite
and augite-andesite, and where these occur the porous submarine
tuffs have become impregnated with auriferous quartz, calcite^
mispickel, and pyrite. These deposits have been mined for gold.
Cadid District. — At Cadia, near Orange, typical graptolite-
bearing carbonaceous shales occur, associated with claystones,
sandstones, and andesite tuffs. The largest iron ore deposit
known in New South Wales occurs associated with these strata.
This bed, which is about 60 feet thick (Fig. 5), lies between two
sheets of andesite, and has been estimated to contain at least-
16
40,000,000 tons of iron ore. Much of this ore, however, con-
tains objectionable quantities of copper and sulphur. Gold and
copper deposits also occur in this region
The iron ore deposits at Carcoar, some distance to the south of
Cadia, are also believed to occur in Ordovician strata ; it is iron
ore from this locality that is now being smelted at Lithgow. The
iron ore deposits of Carcoar and Cadia appear to have been
produced by the alteration of pyritic ore bodies.
Parker-Forbes District. — Rocks of definite Silurian age occur
in this district, but the non-fossiliferous belt of strata in which
the gold reefs occur appears to be a much more highly altered
series, and to be pre-Silurian in age. They have been traced from
the Lachlan River northwards for a distance of about 32 miles.
At Tomingley, about 30 miles still further to the north, similar
strata have yielded Ordovician graptolites. The sediments of the
auriferous belt in the Forbes-Parkes district are very thick, and
consist of a mass of folded schistose slate, arenaceous claystones,
breccias and tuffs, jasperoid and cherty claystones, and what
appear to be andesitic lava flows. Silicification of the sediments
is characteristic of this series, and numerous gold reefs occur in
them. Intrusive andesites appear to have determined the ore
entries.
ORDOVICIAN LIFE.
The following fossils have been obtained from the Ordovician
strata of New South Wales : —
Protozoa — Radiolaria.
Spongida — Protospongia.
Graptolitida — Dicranograptus furcatus, Didymograptus ca-
duceus, Dicellograptus extensus, Dicellograptus elegans.
Diplograptus mucronatus, Diplograptus rectangular is,
Phyllograptus, Diplograptus palmeus, Diplograptus
Carnei, Diplograptus Manduramce, Climacograptus
bicornis, Climacograptus affinis, Climacograptus hastata,
Retiolites caudatus, Cryptograptus, Glossograptus.
Brachiopod s — Obolella .
Pteropoda — Hyolithes.
Trilobita — (?) Agnostus.
This, the oldest fauna yet found in New South Wales, would
seem to have been pelagic in habit, and to resemble fairly closely
that of the Upper Ordovician strata of Victoria. The graptolites
are abundant and widespread, but the other genera are local in
their occurrence. The known fossiliferous beds are few and
far between.
17
Si
Fig. 6.
Ordovician Graptolites.
1. Climacograptm hastata (Hall.). 3. Dicellograptus c. f. divaricatus (Hall).
4. Dicellograptus elegans. 6. Diplograptus Carnei (Hall). 7. Diplograptus foliaceus
(Hall). 8. Climacograptus bicornis (Hall).
SUMMARY OF THE ORDOVICIAN PERIOD.
Of the changes which ushered in the Ordovician Period nothing
is known. The only older formation known to exist in the
districts in which Ordovician sediments are found is the meta-
niorphic series of the Cooma district. As the age of this series
is unknown, it throws no light on the question. The evidence
obtained from the scattered outcrops of Ordovician strata is in
itself very incomplete. Such evidence as these occurrences yield
indicates that the south-eastern and central parts of New South
Wales were covered by the waters of an epicontinental sea
during at least the latter half of the Ordovician Period. The
waters of this sea appear to have been too deep for a shallow
water fauna to flourish, but its surface waters were populated by
a pelagia fauna in which graptolites were the dominant element.
The nearest shore-line was too distant for any but the finer
18
sediments to be transported to these regions and deposited. This
sea also covered the greater part of Victoria. The Ordovician
was a period of considerable volcanic activity, and from sub-
marine volcanoes large andesite lava flows were poured out over
the sea bottom, while at the same time immense quantities of
volcanic ash were distributed far and wide.
At Tallong, the one place where a junction between the
Ordovician sediments and those of the next period has been
observed, a well-marked unconformity occurs. This shows that
at the close of the period extensive earth -movements took place
by which the marine sediments and volcanic rocks, which had
accumulated to a thickness of many thousands of feet were, by
lateral pressure, bent into a series of folds trending approximately
north and south. This folding movement must have converted
much of the area previously under the sea into dry land, which
then became subject to the attack of meteoric forces, by which
the folded Ordovician strata were partly denuded ; consequently,
when the sea readvanced upon these land areas in the next
period, the new beds of sediment were deposited unconformably
upon the truncated ends of the older strata.
A marked feature of the Ordovician formation in New South
Wales is the association with it of valuable metalliferous deposits
in nearly every locality where the formation occurs. In some of
these localities the adjacent Silurian and Devonian formations
appear to be barren of similar ore deposits. It would seem
probable, therefore, that the folding of these strata at the end of
the period, together with the igneous intrusions which accom-
panied it, were responsible for the formation of at least some of
these deposits. From what little is known of them, the igneous
intrusions which took place at this time appear to have been
intermediate in composition.
CHAPTER VI.
THE SILURIAN PERIOD.
SILURIAN rocks are widely distributed in New South Wales, and
outcrop over a larger area, perhaps, than the strata of any other-
geological age ; in addition they probably underlie, to a consider-
able extent, many of the younger sedimentary formations. Strata
of this age, together with the igneous rocks by which they have
been intruded, outcrop extensively in the south-eastern quarter
of the State, particularly about the head waters of the Murray,
Murrumbidaee, and Lachlan Rivers. A second extensive area
is that stretching in a north-westerly direction from the western
fall of the central tableland, past Cobar and Nymagee to the
Darling River. Large outcrops also occur in the far West.
Lithologically the Silurian strata consist mainly of slates and
limestones of marine origin ; littoral deposits such as sandstones,
grits and conglomerates are uncommon. Contemporaneous lavas
and tuffs are of frequent occurrence, and in some cases attain a con-
siderable thickness. The limestones are usually richly fossiliferous,
and in them an abundant and characteristic marine fauna has
been preserved. The slates, on the other hand, are seldom fossil-
iferous, and their geological age has usually been determined by
that of the fossiliferous limestones associated witli them. The
age of considerable areas of these slates has been inferred as
Silurian entirely from lithological resemblances, and as Ordovician
graptolites have recently been obtained from quite a number of
localities where the strata had previously been assumed to be of
Silurian age, it is therefore quite probable that many similar
strata in other localities may ultimately be found to be of Ordo-
vician age also, or even to be younger than Silurian.
The Silurian rocks have invariably been strongly folded and
tilted, the axes of the folds having a nearly meridional strike,
commonly 10° to 20° west of north. This folding has been
accompanied by a moderate amount of regional metamorphism, -
which has had but little effect, in most cases, oh the limestone,
but which has altered the one-time shales into claystones, talcose
slates, &c. The folding has been accompanied by extensive
igneous intrusions, mainly granitic, which have caused consider-
able contact metamorphism, with the resultant conversion of the
adjacent Silurian sediments into slates, phyllites, schists, marble,
20
The Tass-Bowning District. — The great wealth of marine
fossils which occurs in the Silurian rocks of this district has long
attracted attention, and made them a veritable " happy hunting
ground " for the geologist and palaeontologist. The strata, as will
21
be seen from the following sections, consists of conglomerates,
grits, sandstones, shales, limestones, and tuffs, and are upwards
of 4,000 feet in thickness.
SECTION at Yass. (After David.)
feet.
Shales, sandstones, and grit 510
Shales 340
Limestone (with fossil Corals) 20
Shales (with Trilobites, Mollusca, and Molluscoidea) 360
Limestone (Coralline) 40
Grits and shales 270
Limestone (Coralline) 13
Shales and sandstones 680
Andesite lavas, tuffs (about) 1,500
Shales and fine grits 160
Limestones (with Brachiopoda) 10
Shales 160
Limestone (Coralline) 10
Shales and sandstones (with ripple marks and false bedding) 41 0
Total 4,483
SECTION at Bowning. (After Mitchell.)
feet.
Conglomerates 300
Shales and sandstones 50
Conglomerates 50
Shales and sandstones 150
Shales 250
Shales, sandstones, and conglomerates 185
Shales 1,300
Limestone, impure (with Trilobites) 50
Shales (with Corals and Crinoids) 30
Limestone (with Corals, Brachiopods, &c. ) 300
Grits, unknown thickness
So far as it is known, neither the basal nor the topmost beds of
the formation are present in either section. No attempt has
yet been made to correlate the beds which occur at these two
localities. The occurrence of considerable thicknesses of con-
glomerates, grits and sandstones, indicates the proximity of dry
land during their deposition ; too little is known of the boundaries
of this formation, however, for any definite opinion to be formed
as to the extent and position of these land areas. The limestones
and some of the shales are crowded with fossils, corals and
trilobites being particularly abundant.
22
At Boambola, a few miles to the south of Yass, the following
succession of strata (in descending order) has been measured by
Messrs. L. F. Harper and W. S. Dun : —
Thickness in feet.
Grits and shales 200
Limestone (with Syringopora and Heliolites) 30
Shales 100
Impure limestone (with Fa vosites) 25
Shales, sandstones, and quartzites 500
Bouldery limestones 10
Grits, sandstone, and quartzites, with nodules of
limestone 100
Limestone 20
Grits and shales, with limestone nodules 150
Limestones (with Tryplasma and Pentamerus) 100
Grits 100
Shales and rubbly limestones 125
Grits, shales, and quartzites, with ripple-marks and
worm-tracks 1, 200
Glen bower beds (shales, with bands of grit) 840
Total 3,500 feet.
The Glenbower beds contain abundant Silurian fossils, including
Corals (Heliolites, Favosites, C yathophyllum, Tryplasma, Helio-
phyllum), Brachiopods (Pentamerus, Spirifera, Atrypa), Cepha-
lopoda (Orthoceras, Actinoceras), and Trilobites (Phacops and
Encrinurus}. This is a similar fauna to that which occurs in the
Yass beds. This series of strata was undoubtedly deposited
along a shore-line, though at times the stoppage of terriginous
sediments allowed of the formation of the limestone beds ; the
conditions were probably those of intermittent changes in the
level of the land, which brought about an alternating advance
and retreat of the shore-line.
Jenolan District. — This lies in the heart of the Blue Mountains,
and the Silurian strata here are characterised particularly by
the occurrence of Eadiolarian deposits. The lowest beds exposed
consist of red and green clay stones and talcose-slates (Fig. 8),
some of the former containing numerous Radiolarian casts.
Following these, there is a Rhyolite lava-flow, 300 feet in thick-
ness, then comes more claystones, about 300 feet in thickness ;
immediately above these is a massive bed of limestone, about 500
feet in thickness, which is succeeded in turn by beds of clay stone
and Radiolarian chert, upwards of 1,000 feet in thickness. The
whole series has been strongly folded, and the beds now have a
steep angle of dip. In the cherts above the limestone the Radk»-
laria, which are preserved in the form of chalcedonic casts, occur
23
in enormous numbers. The limestone bed has been traced for
many miles in the direction of its strike (N. 10° W.), and consists
Fig. 8.
Silurian Claystones, Jenolan Caves, New South Wales.
mainly of the remains of Corals (Favosites, ffeliolites, <tc.),
Brachiopods (Pentamerus] ,Crinoids, and Hydrozoa (Stromatopora}.
The series, as a whole, has been extensively intruded by granite
24
arid quartz-porphyry, and at the junction of these igneous rocks
with the sedimentary rocks, interesting contact breccias occur,
consisting of subangular fragments of claystone and limestone
embedded in the porphyry. At Wombeyan, some 30 miles to the
south, a thick series of massive limestones and tuffs has been
almost entirely surrounded by plutonic intrusions, and the lime-
stone has been metamorphosed into a coarse white crystalline
marble.
In the limestones at Jenolan, Wombeyan, and Yarrangobilly
occur those wonderful series of caverns whose majestic propor-
tions and infinite variety of form have made them world-famous.
The caves occur where stream channels cross the limestone belts,
and have resulted from the action of water charged with carbon-
dioxide dissolving away the limestone. River gravels, containing
water- worn boulders up to 12 inches or more in diameter, are
frequently met with in these caves, even in those high up on the
hillsides, giving evidence of the fact that the river at one time
flowed through them, as, in fact, it still does through those
at the lowest levels. Percolating rainwater has subsequently
ornamented the walls of the caves with the beautiful stalactitic
and stalagmitic formations, whose bewildering beauty is a never-
ending source of wonder and delight to visitors.
BIG NUGGET HILL.
Fig. 9.
Sketch-section across Big Nugget Hill, near Hargraves, New South Wales, showing
saddle-reefs in folded Silurian Strata. (After Watt.)
The Bathurst District. — The Silurian strata here consist of
alternating beds of claystone and limestone. In the neighbour-
hood of the town of Bathurst they have been extensively
intruded by granite, and have suffered considerable contact
metamorphism therefrom. The limestones have been altered into
crystalline marbles, in which secondary minerals — such as
Wollastonite, Tremolite, Garnet, &c. — are common, whilst the
claystones have been altered into mica-schists, talc-schists,
actinolite-schists, chiastolite-slates, &c. Some of the limestones —
those at the lime-kilns, for example — contain numerous large
cephalopods (Orthoceras, &c.) ; corals are also common, and of
these, Phillipsastrea is perhaps the most characteristic.
25
along
OAKY CREEK
in
PORTIONS NO 249 to 136.
To the north of Bathurst, on the Hill End arid Hargraves
Gold fields, thick beds of tuff and several rhyolit« lava-flows are
interstratified with the Silurian sediments ; these flows range up
to 400 feet in thickness. On the Hargraves Gold-field the folding
of the sedimentary rocks has been accompanied by the formation
of saddle-shaped cavities (Fig. 9) between certain adjacent beds
along the axes of some of the anticlinal folds. These cavities
have been filled subsequently with auriferous quartz, and saddle-
reefs analogous to those occurring on the Bendigo Gold-field in
Victoria have thus been formed. Six distinct lines of these
saddle-reefs are known to occur, but comparatively little mining
work has been done on them.
The Orange-Molong District. — In this district, which is on
the western fall of the Central Tableland of New South
Wales, the Silurian formation consists mainly of slates and
limestones. The limestone beds here are very numerous
and individually attain a SuccESS|ON OF STRATA
thickness of upwards ot
400 feet, but they seldom
maintain this thickness for
any considerable distance,
thinning out rapidly when
followed in the direction
of their strike. Corals,
crinoids, and brachiopoda
have supplied the bulk of
the carbonate of lime for
their formation. At Bore-
nore, Molong, and other ^
localities excellent marbles
of various colours are
obtained from these beds
Towards the top of the
series rhyolite lavas and
tuffs occur to a considerable
extent. The following is
a section of the topmost
beds as they occur along
Oakey Creek, County of
Ashburnham,some 12 miles
from Orange.
Halysites is the most abundant of the fossil corals found here,
and is represented by six different species. Arachnophyllum, a
large and handsome coral, is also plentiful ; it has not yet been
found elsewhere in Australia. Mictocystis is another interesting
but rare genus. The other genera found here include Favosites,
Rhyolite
Green Shales.
Thickness.
Abt.215 Feefc.
815 .. ..
30 .. ..
20 V. "
— — — \ Green Shales 350 ..
50
350
30 •• ••
40 .. »
TuFFs.
Red Shales .
I Crinoidal Limestone
/containing ateo Corals. ^AQ
(Favosites.&c)
Brachiopods. (PencanneruS.SicJ
JTrilobites.vBronteus.&c.)
Fig. 10.
Section showing succession and thickness of
Silurian Strata, Oaky Creek, near Orange, New
South Wales.
26
Heliolites, Mucophyllum, Zaphrentis, and Cyathophyllum. All
have been more or less silicified and are wonderfully well
preserved. The trilobites are not numerous.
The thickness of the Silurian strata in this district is unknown,
but is probably not less than 5,000 feet. The great development
of limestones and the absence of littoral deposits show that
sedimentation was taking place in this region in a comparatively
shallow sea, but at a considerable distance from dry land. The
tuffs and lava-flows indicate that submarine vulcanism became a
pronounced feature towards the close of the period.
In the vicinity of Parkes— Forbes the Silurian strata consist of
sandstones, quartzites, tuffs, conglomerates, limestones, and
laminated claystones folded into gentle anticlines and synclines.
They appear to have been faulted against the (1) Ordovician
strata, and have been traced from Forbes in a northerly direction
for a distance of about 20 miles. In the northern part of the
district the marine sediments appear to have been replaced in
part by andesite flows and tuffs. Typical Silurian fossils occur
in the sedimentary beds, including corals ( Tryplasma, Halysites,
Syringopora, Cyathophyllum, Favosites, Heliolites) ; Brachiopods
(Pentamerus, Leptcena, Orthotetes) ; Trilobites (Phacops, Haus-
mannia). The thickness of these strata is at least 5,000 feet. No
metalliferous deposits are known to occur in these beds, being
-apparently confined to the older Ordovician strata.
The Western Areas. — An extensive development of Silurian
strata is shown on the New South Wales official geological map,
extending in a north-west direction from the Orange-Molong
district nearly to the Darling River. This area embraces the
important mining fields of Cobar, Nymagee, Mount Drysdale,
Mount Hope, and Mount Boppy. The greater part of this region
is relatively flat and covered with surface soil, consequently few
good outcrops occur. As but little detailed survey work has
been completed, the information available is meagre and
unsatisfactory. To what extent Silurian strata are developed in
this region is still doubtful, as the localities, such as Rookery
Station, near Cobar, and Bobadah Station between Cobar and
Nymagee, from which Silurian fossils have been collected, are
few and far between. The strata appear to consist mainly of
slates, claystones, and limestones. The ore deposits, auriferous
and cupriferous for the most part, are in many cases, as at Cobar
for example, of large size, and have been produced by the metaso-
matic replacement of the county rock along shear-zones by ore-
bearing solutions.
Similar areas of Silurian strata (so-called) exist beyond the
Darling River, varying individually from a few square miles to
hundreds of square miles in area. The manner in which the
outcrops of these strata project (like islands) above the surface of
the Mesozoic and Tertiary sediments, suggests that similar strata
underlie these later sediments throughout the greater part of this
western district.
Fig. 11.
Characteristic Silurian Corals.
1. Mucophyllum crat&roides (Eth. flls). 2. Halysites peristephesicus (Eth. fils).
3. Phillipsastrea Currani (Eth. fils) ; section showing the confluent septa. 4. Try-
plasma columnaris (Eth. fils) ; section of a corallite showing the spinose septa and
the tabulae. 5. Heliophyllum Yassense (Eth. flls).
28
ECONOMIC ASPECTS OF THE SILURIAN PERIOD.
Many of the Silurian limestones present a very handsome
appearance when polished, and display considerable variety in
colour and pattern. Some of these have already been extensively
used for ornamental purposes in the buildings of the metropolis ;
the available supply of this material is practically inexhaustable.
Large quantities of limestone are also quarried annually for lime-
burning, cement-making, and for use as a flux in smelting opera-
tions. Of the slates no deposits have yet been found with a
sufficiently perfect fissile structure for use as roofing slates, or for
other building purposes. It is the metalliferous wealth, how-
ever, which gives the Silurian formation its greatest economic
value. Many important gold and copper mining fields are situated
in areas where the enclosing strata are believed to be of Silurian
age. The mineral deposits themselves are, of course, of later
geological ages than the strata with which they are associated, as
they could have been formed only after the latter had been folded
and fractured. Many of these ore-deposits are true " fissure
veins," but some of the larger ones, particularly those containing
copper, are metasomatic replacements of the slates and claystones
along " shear zones." These latter deposits usually have no
definite walls, and the productive ore bodies are more or less
lens-shaped.
SILURIAN LIFE.
The great wealth of fossils found in the Silurian strata of New
South Wales shows that very favourable conditions for the
development of marine invertebrate life must have existed in
the Silurian seas. The great variety of classes, orders, and
genera which constitute this marine fauna is in marked contrast
to that of the preceding Ordovician Period, in the fauna of
which Graptolites so largely predominated.
PROTOZOA. — Radiolaria occurred in enormous numbers in the
Silurian seas, and where conditions were favourable for their
tests to accumulate without too much admixture of other sedi
ment, as at Jenolan, characteristic radiolarian deposits were
formed.
SPONGIDA. — Small sponges occur , but representatives of this
class do not appear to have been abundant.
HYDROZOA. — Graptolites, which occupied such a predominating
position in Ordovician times, are rare. This group apparently
became extinct in Australia during this period. Stromatopora,
a genus allied to the hydrocorallines, becomes very abundant,
and contributed largely to the formation of the limestones of
this period.
29
ACTINOZOA. — These appear suddenly in great numbers. All the
important Palaeozoic groups, viz., the Tetracoralla, the Tabulata,
and the Octacoralla, are represented by numerous families and
genera; many of these were reef building types. Certain genera
such as Holy sites, Mucophyllum, Rhizophyllum, Arachnophyllum,
Phillipsastrea, are, so far as is known, limited in their range in
New South Wales to the Silurian Period. Some had a very wide
geographical range ; others, again, appear to have been confined
to limited areas. The genus Arachnophyllum, for example, occurs
abundantly in the Orange-Molong district, hut is unknown in
the Yass-Bowning district. Such restrictions are due, most
probably, to differences of environment rather than to land
harriers preventing migration. Individual coralla among the
compound corals attained large dimensions.
Fig. 12.
A Silurian Bryozoan. Fenestella propinqua (De Kon.).
ECHINODERMATA. — Crinoids occurred in immense numbers ;
certain parts of the sea bottom, at times, must have been covered
with veritable "forests" of these organisms, as large thicknesses
of limestone in various localities consist very largely of " crinoid
stems." Owing to the fragmental state in which they have been
preserved, little is known of the genera to which they belonged.
Star fish and echinoids are rare.
BRYOZOA. — Generally speaking, these are not common. Con-
siderable numbers, however, occur in some of the Yass beds
30
Fig. 13.
Characteristic Silurian Brachiopods.
1-6. Pentamerus (Conchidium) Knightii.
7-8. Pentamerus cestatus.
Fig. 14.
Weathered specimen of Pentamerus in limestone.
particularly in those
in which the Trilo-
bites are found. The
most common genus
is Fenestella (Fig.
12).
BRACHIOPODS.—
These stand second
in importance to the
corals, and flourished
abundantly in the
Silurian seas. The
cosmopolitan species
Pentamerus Knightii
(Fig. 14) and A try pa
reticularis are the
most abundant ; the
former, in particu-
lar, contributed very
largely to the forma-
tion of some of the
limestone beds.
MOLLUSCA.— These
occupy a very secon-
dary position as com-
pared with the Bra-
chiopods, but were
abundant in some lo-
calities. Pelecypods
are 'not common.
Gasteropods are rep-
resented by such
genera as Loxonema,
Murchisonia, Orio-
stoma, Cyclonema.
The Cephalopods all
belonged to the
straight-shelled nau-
tiloid types, such as
Orthoceras, which in-
dividually attained
a considerable size,
and in certain lo-
calities occurs in
considerable num
bers.
31
TRILOBITA. — These flourished in great numbers in the Silurian
seas, covering what is now the Yass-Bowning district. The
muddy, shallow water of the shore-line seems to have been their
favourite habitat. Elsewhere they appear to have been un-
common. Over fifteen genera and a large number of species
have already been described. Encrinurus (Fig. 15), Phacops
(Fig. 15), Hausmannia, and Bronteus are the most common
genera.
Fig. 15.
Silurian Trilobites.
1. Encrinurus Mitchelli. 2. Cephalon of Encrinurus Barrandi (De Kon.).
3. Phacops.
Plants. — -Impressions of Algse (sea-weeds) are found in some
of the marine shales, but no trace of any terrestrial vegetation
has yet come to light. The high state of development of the
land flora of the next period (Devonian), and the marked differen-
tiation exhibited by the different groups represented, makes it
highly probable that their progenitors already existed in Silurian
times.
LIST OF THE MORE IMPORTANT SILURIAN FOSSILS.
Protozoa — Radiolaria were abundant.
Spongida — Astylospongia, Receptaculites.
Hy drozoa — Strom a topora. *
* These genera are the most abundant.
32
Actinozoa — (a) TETRACORALLA, Petraia, Zaphrentis, Muco-
phyllum, Gyathophyllum,* Tryplasma,* J'Tiillipsastrea,
Heliophyllum, Rhizophyllum , Arachnophyllum, Spon-
gophyllum* (b) TABULATA Favosites* Pachypora,
Chcetetes, Haly sites* Syringopora* Striatopora.
(c) OCTOCORALLA, Heliolites* •
Crinoidea — Pisocrinus.
Echinoidea — Palechinus,
Asteroidea— Patefer.
Vermes — Jaws of Errant Annelids occur.
Bryozoa — Fenestella,* Glauconome, Thamniscus.
Brachiopoda — Lingula, Pentamerus (Conchidiurn),* Atrypa*
Rhynclionella,* A noplotheca, Camarotcechia, Meristina,
Cyrtina, Strophomena, Orthotetes, Spirifer., Orthis.
Pelecypoda — Conocardium, Anodontopsis.
Gasteropoda — Euomphalus, Trochus, Cyclonema, Oriostoma,
Bellerophon, Loxonema,* Murchisonia, Omphalotrockus,
Mourlonia.
Pteropoda — Tentaculites, Hyolithes.
Cephalopoda — Orthoceras* Actinoceras, Gomphoceras.
Trilobita — Acidaspis, Cromus, Eucrinurus* Calymene,*
Harpes, Bronteus,* Cheirurus, Praetus, Phacops*
Cyphaspis, Lichas, Staurocephalus, Il/.wnus, Haus-
mannia*
SUMMARY OF THE SILURIAN PERIOD.
The earth movements which closed the Ordovician Period were
followed in New South Wales by long-continued sedimentation.
The nature and distribution of the sediments then deposited, so far
as our knoweldge goes, indicates that the greater part of New South
Wales, perhaps nearly all of it, was covered by the sea. The oc-
currence of littoral deposits (conglomerates, grit, sandstones, &c.)in
the Yass-Bowning and the Parkes-Forbes districts points to the
existence of neighbouring land in these areas. This land probably
lay to the south, it»ut our present knowledge of the distribution of
these littoral deposits is too incomplete to attempt a reconstruction
of the boundaries of Silurian land and sea. Elsewhere, littoral
deposits appear to be absent, while the general occurrence of
alternating claystones and limestones indicates tranquil deposition
in a comparatively shallow open sea. The abundance of reef-
building corals shows the water of this sea to have been warm, as
these organisms, judging by their present day representatives,
cannot live in water with a lower temperature than 68° Fahren-
heit. The great thickness of strata deposited, perhaps 10,000
These genera are the most abundant.
33
feet, could only have been possible if the sea bottom had been
slowly subsiding, while the alternation of claystones and lime-
stones indicates that the subsidence was more or less intermittent.
Thia tranquil and long-continued sedimentation was at times
interrupted, particularly towards the close of the period, by
submarine volcanic eruptions, which covered the surrounding
sea-floor with large deposits of volcanic ash and lava.
At the close of the Silurian Period, a pronounced deformative
movement affected the earth's crust, which folded and elevated
the Silurian strata to such an extent that considerable areas were
probably uplifted above sea-level. Our incomplete knowledge of
the nature and distribution of the succeeding Devonian sediments
makes it impossible to form any definite opinion as to the extent
of this movement, or of the position and actual extent of the land
areas produced by it. This will be discussed more fully in the
next chapter.
3910— B
CHAPTER VII.
THE DEVONIAN PERIOD.
THE distribution of the Devonian Formation corresponds, in a
general way, with that of the Silurian, but the superficial area at
present occupied by it is very much smaller. The outcrops,
I I
35
particularly those of the
Upper Devonian Series,
are, as a rule, individually
small in area, and are often
widely separated from one
another. These isolated
outcrops appear to be the
remnants of what was, at
one time, a very exten-
sive formation. Extensive
areas, however, do occur,
such as that of the Mount
Lambie-Capertee district,
on the western edge of the
Blue Mountains.
The New South Wales
Devonian strata have been
provisionally divided into
two series, as follows : —
The Upper Devonian
Series (Lambian Series)
— Mt. Lambie, Caper-
tee, Molong, Braid-
wood, and Yalwal Beds.
The Lower Devonian
Series (Murrumbidgean
Series)— TheTamworth
Beds; the Murrumbid-
gee Beds.
THE LOWER DEVONIAN OR
MURRUMBIDGEAN SERIES.
This series has, some-
times, been referred to the
Middle Devonian Epoch,
following the classification
used in Victoria. The
strata are all marine in
origin, and have yielded an
abundant fossil fauna, in
which corals are the most
conspicuous element. Lith-
ologically the strata are not
unlike those of the Silurian
formation, but important
differences occur in the con-
tained fossils. Littoral de-
posits appear to be absent.
_ •
_S'N
!>'-
*
1 •§!
2 £..
ail
m
II
-
36
I. The Murrumbidgee Beds. — -These occur along the course of
the Murrumbidgee River, immediately above its junction with
the Goodradigbee River, and extend for a considerable distance
to the south along the watershed of the latter. The junction of
these beds with the adjoining Silurian strata is obscure, the two
being separated by extensive quartz-porphyry intrusions (Fig. 17) ;
but a strong unconformity is believed to exist. The Murrumbidgee
Beds, as measured by Mr. L. F. Harper, have an average total
thickness of about 14,000 feet, and consist of the following
rocks : — •
Maximum Thickness
feet.
Dark-blue shales (with interbedded tuffs) ... 7,000
Limestones (with interbedded shales and tuffs).. 5,000
Rhyolite lavas and tuffs (volcanic stage) . . . 5,000
(a] The Volcanic Stage. — This occurs at the base of the series,
and consists of rhyolite lava-flows and tuffs. These may be
correlated with the Snowy River porphyries of Victoria, occupying
a similar stratigraphical position in that State, and which they
much resemble in their lithological characters. The thickness of
the volcanic beds is variable, but they attain a maximum
thickness of 5,000 feet at Cavan. They are believed to have
been derived from several distinct centres of eruption.
(b) The Limestone Stage. — This has a maximum thickness of
about 5,000 feet, and, in addition to the limestone, includes
numerous thin beds of shale, quartzite, and tuff. The limestones
are largely coralline in origin, but some of the beds near the base
of the series are built up mainly of brachiopod shells (Spirifer,
Chonetes, &c.). The following detailed section of the lower beds
of this stage, and of the volcanic beds, as they occur at Cavan,
has been measured by Mr. Harper : —
Limestone Stage.
Thickness,
feet.
Second limestone series ... ... (Not measured.)
Siliceous shales and quartzites (with
lenticular limestone beds) ... 1,800
Basal limestone series ... ... 2,250
Tuffs (with bands of shale and lime-
stone) 150
Volcanic Stage.
Rhyolite tuff 100
Rhyolite lavas and tuffs 5,000
The great thickness of limestone in this series is only equalled
in Eastern Australia by that of the Burdekin Beds of Queensland,
which are also of Devonian age.
37
(c) The Tuffaceous Shale Stage. — The dark-blue shales which
follow the limestone stage not only include definite beds of tuff,
but are, more or less, tuffaceous throughout. Several small
rhyolite flows occur near the top of the series.
It has been estimated that at least 8,000 feet of the Murrum-
bidgee Beds are composed wholly or partly of volcanic material.
The limestone series and the overlying blue shales may be taken
as the equivalents of the Middle Devonian formations of Victoria
(Buchan and Bindi Beds). Similar limestone beds to those on
the Murrumbidgee have been observed as far south as Lobbs'
Hole, and occur on the Snowy River, just across the Victorian
border. The following is a comparison of the Devonian rocks of
Western Victoria and Southern New South Wales : —
New South Wales
Victoria.
Upper Devonian
Middle Devonian
Lower Devonian
Mount Tambo and
Iguana Creek Beds.
Buchan
Beds.
and Bindi
Por-
(Southern).
Genoa Creek, Pambula,
and Braid wood Beds.
/ Murrumbidgee Beds —
J Tuffaceous shale stage.
j Murrumbidgee Beds —
\ Limestone stage.
Murrumbidgee Beds-
Volcanic stage.
Snowy River
phyries.
There seems to be no reason for separating the volcanic stage
of the Murrumbidgee Beds from the overlying marine beds ; the
two appear to be conformable, and the volcanicity continued, to
a greater or less degree, throughout the deposition of the marine
strata.
II. The Tamworth Beds. — The Lower Devonian formation in
the Tamworth district is described by Messrs. David and Pittman
as having a thickness of upwards of 9,000 feet, and consisting of
coralline limestones, radiolarian limestones, claystones, tuffs,
and radiolarian cherts. The following section has been measured
by them :— Thickness.
feet.
Claystones and tuffs with Lepidodendron ... 1,450
Cherty-shales with beds of tuff and lenticular
beds of radiolarian limestone 1 , 430
Claystones, tuffs, radiolarian cherts, and radio-
larian limestones ... ... ... ... 1,960
Tuffs with Lepidodendron Australe ... ... 7
Claystones with Lepidodendron Australe ... 50
Radiolarian cherty shales with interbedded
radiolarian limestones and tuffs ... ... 4,150
Coralline limestones 140-1,000
Claystones ... ... ... ... Unknown thickness.
38
It will be seen that the basal volcanic series of the Murrum-
bidgee area is apparently absent here ; nevertheless loti'g-continued
volcanic activity is evidenced in the abundance of volcanic ash
which occurs throughout the series. This volcanic material
varies from acidic to intermediate in composition, and some of
the tilff beds individually attain a thickness of 100 feet. The
limestone beds of the two areas are not very similar in their
fossil contents,' as will be seen from a comparison of the fossils
given later. The beds which succeed the limestones possess two
features of special interest ; (1) the great abundance of Radiolaria ;
(2) the occurrence of Lepidodendron Avstrale. In the Black
Cherts radiolarian casts occur to the extent of 1,000,000 to the
cubic inch, and the rock contains over 90 per cent, of silica.
The claystones also contain casts of these organisms, but in a
lesser degree ; these beds are fine-grained, often minutely
laminated, and are occasionally ripple-marked. The radiolarian
limestones occur as thin lenticular beds, varying from a few
inches up to 2 feet in thickness, and are irregularly interstratified
with the other radiolarian rocks. In composition they consist
largely of carbonate of lime, but contain about 18 per cent, of
silica, the latter due mainly to the presence of the radiolaria ; as
no other fossils have yet been found in them, the source of the
carbonate of lime is unknown. It will be seen that all of the
Tarn worth Devonian rocks are remarkably fine-grained in tex.ture ;
this fact, together with the abundance of radiolaria, might be
taken to indicate that they were deposited in deep water. The
presence, however, of plant remains (Lepidodendron) on at least
three distinct horizons, the occurrence of limestone beds, and of
ripple-marks on some of the shales, are opposed to this view.
It seems probable, therefore, that this series of strata was
deposited in a sea, not necessarily very deep, but sufficiently far
removed from land to be beyond the reach of any but the very
finest sediment.
i Bingera and Barraba Districts. — A series of strata occurs here,
not unlike that of the Tarn worth district, consisting of jointed
claystones with numerous interstratified beds of tuff and
occasional thick beds of coralline limestone. Some of the beds
contain numerous radiolaria, and in some of them Lepidodendron
Australe is abundant. This series is, no doubt, an extension of
the Tamworth beds. A very conspicuous feature in the district
is a dyke-like belt of serpentine, from a quarter to half a mile in
width, extending in a south-south-east direction from Bingera for
a distance of about 180 miles. This rock, which is an altered
peridotite, intrudes the Devonian strata ; a zone of red and dark
grey'jasperoid cherts, several hundreds of feet in width, occurs
alonjg the junction and contain abundant radiolarian casts. This
intrusion has materially influenced the metalliferous character
39
of the adjoining sedimentary rocks, with the result that numerous
auriferous reefs occur in them in close proximity to it as at
Bingera, Wood's Reef, Ironbark, Bowling Alley Point, and
Nundle.
Fig. 18.
Lower Devonian Corals and (?) Sponges.
1. CyathophyHiim Mitchelli. 2. Syringopora speleana. 3. Diphyphyllum gemmiforme.
4 and 5. Receptaculites Australis.
LOWER DEVONIAN LIFE.
The following are lists of the fossils collected from the two
important districts where rocks of this age are developed.
Murrumbidgee District.
Plantse—
Spongida- —Receptaculites Australis.
Hydrozoa —
Strom atopora.
Tarn worth District.
Lepidodendron.
Stromatopora.
40
Actinozoa—
Diphyphyllum gemmiforme.
Cyathophyllum Mitchelli.
Syringopora speleana.
Favosites.
Cystiphyllum.
Zaphrentis.
Campophyllum.
Diphyphyllum Porteri.
,, robustum.
Syringopora auloporoides*
„ Porteri.
Favosites gothlandica.
,, basaltica.
Sanidophyllum Davidis.
Spongophyllum giganteum.
Actinocystis.
Alveolites alveolaris.
Litophyllum Konincki.
Heliolites porosa.
Brachiopoda —
Spirifer Yassense. Atrypa reticularis.
Chonetes Culleni.
Rhynconella Wilsoni.
Atrypa desquamata.
Gasteropoda —
Pleurotomaria.
Murchisonia.
Bellerophon.
Dentalium tenuissimum.
Cephalopoda — Orthoceras.
Pisces — Ganorhyncus Sussmilchii.
PROTOZOA. — Radiolaria were locally abundant (Tamworth Beds).
Foraminifera are unknown.
PORIFERA. — Receptaculites, an organism whose true affinities are
still uncertain, occurs in abundance in the Murrumbidgee Beds.
CCELENTERATA. — Corals still retain the dominating position
they held in the Silurian Period. Of the Tabulata, Halysites was
extinct, but Favosites and Syringopora continued to flourish, the
latter in even greater abundance than before ; the former is
represented mainly by branching types. Of the Tetracoralla, the
genus Diphyphyllum occurs in large numbers, and is, perhaps, the
most distinctive of the Lower Devonian corals ; Cyathophyllum
is still abundant, but Mucophyllum, Heliophyllum, and other
typical Silurian genera have become extinct. The Cystiphyllidse
are more strongly represented, such genera as Spongophyllum
and Actinocystis being abundant, but Rhizophyllum is absent.
Heliolites (Octocoralla) is still very plentiful.
MOLLUSCOIDEA. — Brachipods were locally abundant, particu-
larly the genera Spirifer and Chonetes ; these occur in enormous
numbers in some of the Murrumbidgee Beds. Atrypa still lingers
on, but Pentamerus, so characteristic of the Silurian period, is
absent.
41
MOLLUSCA. — Cephalopods were large and numerous, the straight-
shelled types, such as Orthoceras, still predominating. The
Gasteropods were still represented mainly by long turreted forms
(Murchisonia, &c.) ; but genera with depressed shells, such as
Setlerophon, become more common. Pelecypods appear to have
been rare.
Fig.119.
Lower Devonian Molluscoidea and Mollusca.
1 and 2. Chonetes Culleni. 3. Murchisonia turris. 4. Orthoceras subdimidiatum.
5. Loxonema anglicum. 6, 6a, 6b. Spirifer Yassemis.
CRUSTACEA. — No Trilobites or other Crustacea have yet been
found.
VERTEBRATA. — The Murrumbidgee Beds have yielded one fossil
fish, Ganorhyncus, which must have been about 5 feet in length,
and belonged to the Dipnoi. This is one of the oldest recorded
fish for Australia.
42
!**•
a «
ll
g '%
The Flora. — The lycopod, Lepido-
dendron, if the age assigned to the
beds in which it occurs at Tarn worth
is correct, must have occurred in
abundance. No other fossil plants are
known.
Comparison of the Murrumbidgee and
Tamworth Faunas. — The fossil fauna
of the Murrumbidgee Beds differs
markedly from that of the Silurian
period. There is an entire absence
of such characteristic Silurian corals as
Halysites, Mucophyllum, Tryplasma,
Heliophyllum, ifec. On the other hand,
Diphyphyllum, the most characteristic
of the corals of the Murrumbidgee
Beds, does not occur in Silurian strata.
Similarly, the brachiopod, Pentamerus,
is absent from the Murrumbidgee Beds.
Such genera as are common to both
formations are represented for the most
part by different species.
While the fossil fauna of the Tam-
worth Beds also differs from that of
the Silurian period, it, in addition,
displays a marked difference from that
of the Murrumbidgee Beds. Mr. W. S.
Dun has pointed out that the Tam-
worth fauna, as a whole, is more closely
related to that of the former than it is
"to the latter.
If the faunas of the Murrumbidgee
and Tamworth Beds were contempo-
raneous they certainly must have been
provincial faunas, i.e., were evolved in
seas so isolated from one another that
intermigration was practically impos-
sible. The fossil lycopod, Lepido-
dendron, is unknown from both the
Silurian strata and the Murrumbidgee
Beds ; it is, on the other hand, very
common in Upper Devonian strata.
This raises the question as to whether
the Lepidodendron-bearing strata of
Tamworth should not be correlated
with the Upper Devonian Beds.
43
THE UPPER DEVONIAN OR LAMBRIAN SERIES.
Mount Lambie Beds. — The best known occurrence of Upper
Devonian strata is that occurring along the western edge of the
Blue Mountain Tableland. At Mount Lambie (near Rydal) this
formation has a thickness of not less than 10,000 feet, and
includes shales, claystones, sandstones, and quartzites, the last
predominating. Marine fossils occur in abundance in some of
the strata, and consist mainly of Brachiopods (Spirifer, Rhyn-
chonella, Lingula) and Pelecypods, the former largely pre-
dominating. In these marine beds drift Lepidodendron also
occurs.
At Capertee, some distance to the north-east of Mount Lambie,
the formation consists of quartzites, conglomerates, claystones,
&nd limestones. The limestone beds are usually thin, but some-
times thicken into solid masses of considerable extent ; they
SOLITARY CREEK.
Fig. 21.
Section of Upper Devonian Strata, near Mount Lambie. (After David and Pittman.)
A = Granite. B = Quartzite, with Spirifer disjuncta and Lepidodendron Australe.
-C = Ferruginous shales. D = Grey shales, with obscure plant impressions.
E = Conglomerate. F = Quartzites and shales, with Lepidodendron.
Contain fossil corals (Favosites, Heliolites, Syringopora, and
Cyathophyllum). This occurrence of a coralline limestone in the
Upper Devonian formation of New South Wales is unusual. The
whole series has been folded into symmetrical anticlines and
«ynclines.
In the adjoining Mudgee-Hargraves district, thick beds of
tuff and contemporaneous lava-flows occur at the base of the
series These flows consist of rhyolite and augite-andesite.
Conglomerates are also strongly developed in this region.
SUCCESSION OF STRATA
along"
GAP* SPRING CREEKS.
Quarbzibes
and
Sandstones
^Shales* Sandstones
> with Lmgula.SpiHfer 186
Rhynconella .Favosites.fcc
> Red Sandstones w.t* 200
Thin band of Conglomerate
=r--^=-g-- ^Shales
30* .. ..
Conglomerates
with inberbedded 413 ..
Red Shale *Sandstones
. . Protaklt small unconform/Cy here
•*f-,'v I Red TuFFs with bands of
J^Llk^^- ' rgreen cherty shales & 2
j_" '.; '-• :• : I 6large masses of Rhyolite.
238
:Z%e Molong-C 'anobolas Beds. — Immediately to the west of the
Canobolas Mountains the following succession of strata occurs : —
The Devonian strata
shown represent only a
portion of the original
Thickness. thickness, much having
been removed by subse-
382feet quent denudation. They
rest uncomformably up-
on the Silurian strata,
and the basal conglome-
rates contain waterworn
pebbles of the Silurian
limestone. All the beds,
with the exception of
some of shales, have
a more or less red colour,
the sandstones in par-
ticular presenting a typi-
cal "old red sandstone"
appearance. Many of the
strata exhibit current-
bedding, ripple-marks,
335 and annelid tracks. The
whole series must, there-
fore, have been deposited
in shallow water along a
shore-line. As is usual
ao .. .. in New South Wales,,
the fossils are nearly
all brachiopods, and
these include Spirifer
disjuncta, RJiynchonella
pleurodon, and Lingula
gregaria. Some plates of
Fig. 22. a placo- ganoid tish have
Section showing thickness and succession of Silurian also been found here,
and Devonian Strata at Gap Creek, Orange District. At Qanowindra, some
30 miles to the south,
similar Upper Devonian shales and sandstones occur, containing
in one and the same stratum the fossil shell Lingula gregaria
and the fossil plant Lepidodendron ; these plant remains
evidently drifted to their present position. At Wellington,
about 60 miles to the north of the Molong locality, a massive
series of Upper Devonian conglomerates, quartzites, and shales
occurs, also containing Spirifer disjuncta and RJiynchonella.
pleurodon.
: : '••••'.
•
—
•
R
L
(T
. — —
—
Efs^di"
r
&£
=>rc>T<:=>..'°<=>Ta.
CT, «=> <i tfjjp
*^s>*
-yvs?^.-.
^
<'<=£<*
^<J®i?
^^•^o.V-
5|E
','"r~l.~
.•".&.'•'. '-;<y.';'
}
—
— — -
—
— : — =
*^
"'TT. n
>
—
— —
—=_
Green Shales with
occasional thin
.bands oMine-
-grained Tuff
Coralline Limestone
with Halysitee.&c
Shales & Tuf Fs
In the Parkes-Forbes dis-
trict the Devonian system
is represented by a much
denuded series of quartzites,
sandstones, and chocolate and
greenish-grey coloured shales.
The thickness of the beds ex-
posed to the east of Parkes
exceeds 5,000 feet. A pecu-
liarity of the series is the
repeated alternation of quartz-
ites and chocolate-coloured
shales. Specimens of Lepi-
dodendron Austrcde and of
fish-scales and plates are fairly
common in these beds. From
one locality the formation has
yielded poorly preserved speci-
mens of Rhychonella, Pteri-
ncea, and Orthis.
Many other outcrops, some
of them covering considerable
areas and consisting of similar
massive conglomerates, quartz-
ites, and shales, occur in
various localities in the wes-
tern districts of New South
Wales. These occurrences
have not yet been systematic-
ally examined, and have, in
nearly all cases, been referred
to the Upper Devonian, from
their lithological character
only. Mr. E. C. Andrews
has quite recently mapped an
extensive series of Upper De-
vonian strata in the Cobar
district, lying immediately
to the west of the Silurian
mineral belt. They resemble
the Mount Lambie Beds in
their lithological characters,
and contain imperfectly-pre-
served brachiopod shells and
crinoid stems.
South - Eastern District. —
Extensive areas of similar
46
strata occur in the south-eastern district extending at intervals
from the Shoalhaven River to the Victorian border. In the County
of Auckland these strata have a thickness of upwards of 1,200
feet. Here, in the Narrungutta and Yambulla Ranges, the beds
are nearly horizontal, but on the Wolumla gold-field they have
suffered considerable folding. In some of them ripple-marks and
47
annelid tracks are not uncommon.' On the Genoa River fresh-
water or estuarine shales, which occur near the top of the series,
have yielded the following fossil plants : —
Pecopteris obscura.
Sphenopteris Carnei.
Archceopteris Howitti.
Cordaites Australia.
These are the oldest fresh-water beds yet observed in
South Wales. Farther to the north on the Pambula gold-field a
thick series of Upper Devonian strata is seen resting unconform-
ably upon the Silurian beds. On the Yalwal gold-field, still
further to the north, contemporaneous lava-flows and tuffs are
associated with similar Upper Devonian strata ; rhyolite and
basalt flows apparently alternate with one another, and the
former outcrop on a grand scale for miles along the Upper
Danjera Creek, forming precipitous walls to the gorge. Fluxion
and spherulitic structures are particularly \vell developed in the
rhyolites. Certain belts of these, Devonian strata have been
impregnated with gold, along what are probably shear zones, and
have been extensively mined for that metal.
Fig. 24.
Upper Devonian Fossils .
1. Lepidodendron Australe. 2. Pteronites Pittmani. 31. Spirijer disjunctus^
4. Rhynbonella pleurodon'.
48
UPPER DEVONIAN LIFE.
The following is a list of the more important fossils at present
known from these beds : —
Hydrozoa — -Stromatopora.
Actinozoa — Heliolites, Favosites, Syringopora (three species).
Crinoidea — Crinoid stems.
Vermes — Annelid tracks.
Bryozoa — Fenestella.
Brachiopods — Lingula gregaria. Spirifer disjuncta, Spirifer
Jaqueti, Rhynchonella pleurodon, Chonetes, Athyris, Atrypa,
Leptcena rhomboidalis.
Pelecypoda — Pteronites Pittmani, Leptodomus, Aviculopecten,
Pterinea.
Gasteropoda — Loxonema, Murchisonia, Euomplialus Culleni,
Bellerophon.
Pisces — Plates of placo-ganoid fish.
Filicales — Pecopteris obseura, Sphenopteris Carnei, Archceopteris
Howilti.
Lycopodiales — Lepidodendron Australe.
Cordaitese — Cordaites Australia.
The fauna, so far as we know it, is for the most part a littoral
one in which Brachiopods predominate. The two cosmopolitan
species Spirifer disjuncta and Rhynconella pleurodon are particu-
larly abundant, certain beds being literally crowded with their
shells. Lingula is also abundant at some localities. The sea-
bottom where these brachiopod shells accumulated must have been
not unlike the oyster-banks of the present day. Pelecypods were
numerous, and belonged largely to the oblique-winged aviculids.
The gasteropods were less numerous, the long turreted forms of
the Silurian and Lower Devonian now giving place to flattened
types sfich as Euomphalus and Bellerophon. The Brachiopods
and Mollusca, although numerous, do not seem to have attained
large dimensions as individuals. The shallow waters of the Upper
Devonian seas, constantly receiving large quantities of sediment
from the neighbouring land, were unfitted for such organisms as
crinoids and corals to live in, and as one would expect, their
remains are seldom found in these Devonian strata. Coralline
limestones occur in the Capertee district, and probably represent
temporary local conditions of open and clear waters in which the
coral polyps were able to flourish.
The absence of trilobites is not easy of explanation ; they
flourished abundantly in the Silurian, and as we find them also
in considerable numbers in the Carboniferous, they evidently had
49
not become extinct. The muddy waters of the Upper Devonian
should have provided a suitable habitat for them. Very little
collecting has been done in these strata however, and they may
still be found in them. Fragmentary fish remains have been
obtained from several localities, but little is at yet known about
the fish to which they belonged.
The Devonian Flora. — This fiora is interesting as being the
oldest yet discovered in Australia ; it includes ferns, lycopods,
and cordaitese. The occurrence of such widely different groups of
land-plants living side by side in this period is a strong argument
in favour of the existence of a terrestial fiora in the Silurian
period, or even earlier. A long period of time must have been
necessary for the evolution of such diverse types of plants as this
fiora displays. Lepidodendron is the most abundant and widely
distributed of the Devonian plants, due, no doubt, to the fact
that its trunks and branches were able to survive transportation
by sea and to resist decomposition long enough to become water-
logged and thus be buried in the Devonian marine sediments.
The scarcity of the other members of this flora is due, no doubt,
to the comparative absences of known fresh-water strata; the
ferns found in the Genoa Creek beds were, no doubt, just as
widely distributed on the Devonian land surfaces as Lepido-
dendron was.
SUMMARY OF THE DEVONIAN PERIOD.
Our knowledge of the Devonian formation in New South
Wales is so incomplete that it is difficult to make any broad
generalisations as to the geographical conditions and earth
movements of this period. The conclusions advanced here are
therefore tentative, and will, no doubt, need considerable modifica-
tion as fuller information becomes available.
It has been shown that Devonian strata of two different types
occur in New South Wales, and that they have been referred to
the Lower and Upper Devonian epochs respectively. Both the
Upper and Lower series are uncomformable with the Silurian
strata, but their stratigraphical relation to one another is quite
unknown, as no junction between them has yet been found, nor
are both known to occur in one and the same district. In
Victoria, however, the Upper Devonian strata (Mt. Tambo beds,
Iguana Creek beds) rest directly upon the Middle Devonian beds
of these localities, and the junction between them shows a
marked uncomformity. The Upper Devonian strata of Victoria,
however, are all believed to be fresh-water beds. Judging by the
known distribution of the Lower Devonian beds in New South
Wales, the deformative movement which closed the Silurian
50
Period must have raised a considerable portion of the State above
sea level, leaving, however, at least two considerable areas still
under marine conditions, one in the south, stretching from the
Murrumbidgee River southwards into Victoria, the other to the
north, in what is now the Tarn worth -Barraba district. The
littoral deposits, whose deposition might reasonably be expected
to have followed this extensive uplift, do not apparently exist,
or if they do have still to be found ; off-shore deposits, such as
shales and limestones, are the prevailing rock types. Vulcanisrn
was a pronounced feature, particularly at the beginning of the
period, and continued intermittently throughout ; the main
centres of eruption seem to have been in the south.
As already pointed out, the fossil faunas of these two areas
indicate that if they were contemporaneous the seas in which
they lived could not have been in direct communication, but
must have been separated from one another by a land barrier
which prevented the new species evolved in either area from
migrating to the other.
Marine life was abundant in these seas, and reference to the
lists of fossils already given will show that reef-building corals
flourished, while, in the Murrumbidgee region, Brachiopods and
the various groups of Mollusca were also well represented. From
these beds the oldest vertebrates yet found in Australia have
been obtained. These were primitive fish, belonging to a group
called the Dipnoi ; an allied genus, Ceratodus, still survives in
Queensland.
Assuming that the Upper Devonian strata were deposited
later than the Lower Devonian strata, and that a marked
unconformity exists between them in New South Wales, as
appears to be the case in Victoria, then a deformative
movement must have followed the deposition of the Lower
Devonian sediments. The wide extent of the Upper Devonian
strata indicates that this must have been followed by an extensive
subsidence, which allowed of the 'formation of broad shallow
epicontinental seas, in which the Upper Devonian sediments
were deposited. The common occurrence of conglomerates, grits,
and sandstones indicates the existence of considerable areas of
dry land at no great distance to provide the necessary material
for their formation ; this supposition is supported by the presence
of 'abundant drift-wood in the same strata. It is impossible, with
our present deficient knowledge, to reconstruct the geography of
New South Wales as it was at this time, but it seems probable
that there existed an archipelago of large islands separated by
broad, shallow^ epicontinental seas. An abundant marine inver-
tebrate fauna, consisting of Braehipods, Pelecypods, and
Gasteropods inhabited these seas. Vertebrate animals were
51
represented by fish only, which appear to have I »een both large
and numerous. , That the neighbouring land was clothed with
vegetation is shown by the abundant drift Lepidodendron which
is found in these marine strata and the occurrence of plant beds
near the Victorian border. These plants were all Cyptogams
(lycopods and ferns).
An alternative explanation of the relations between the Lower
and Upper Devonian formations, however, suggests itself, and
that is, that the two formations were deposited more or less
contemporaneously, the former in an open but comparatively
shallow epicontinental sea, at some distance from a shore-line ;
the latter in the shallow coastal waters of the same sea. The
marked differences in the faunas of the two formations would be
due in this case to differences of environment. It has already
been pointed out that the beds of the typical Murrumbidgee type
and of the typical Mount Lambie type do not occur in one and
the same districts ; that fact lends some support to this view.
The occurrences of Lepidodendron Australe in the beds above
the coralline limestones in the so-called Lower Devonian beds at
Tamworth, and the occurrence of a coralline limestone with
flavosites, Heliolites, and Syringopora in the Upper Devonian
formation near Capertee supplies additional evidence. One would,
of course, if this view were the correct one, expect to find formations
somewhat intermediate in character between the characteristic
Murrumbidgee and Mount Lambie types ; these, however, may yet
he found. Until further evidence is available it would be prefer-
able, therefore, to use the terms Murrumbidgean and Lambian in
lieu of Lower and Upper Devonian.
CLOSE OF THE DEVONIAN PERIOD (KANIMBLA EPOCH).
The close of this period was one of the greatest mountain-
making epochs of New South Wales ; and no part of the State,
excepting the North -Eastern section, has since been subjected to
similar orogenic earth movements. Throughout the central and
southern tablelands the Ordovician, Silurian, and Devonian strata
are strongly folded, Carboniferous strata are absent, and the
strata of the succeeding period (Permo-Carboniferous) rest upon
the Devonian and earlier formations with a marked unconformity.
These Permo-Carboniferous strata are either quite horizontal or
have a very low angle of dip; and have not been folded ; their
present elevation above sea level is due to epeirogenic movements
(vertical uplift) only. Throughout the greater part of this area
the two lowest subdivisions of the Permo-Carboniferous series,
viz., the Lower Marine Series and the Lower Coal Measures, are
absent, the Upper Marine Series resting directly upon the denuded
of the Devonian or older strata. It is apparent, therefore.
52
that the orogenic movements which folded the Devonian strata in
the region under consideration must have taken place before the
Permo-Carboniferous strata were laid down, probably also before
the Carboniferous sediments to the north were deposited. This
latter opinion is supported by the fact that when the Permo-
Carboniferous seas invaded this area, the Devonian strata had
been so deeply denuded as to expose extensively the large granite
bathyliths by which they had been intruded. (See Fig. 52.)
The folding, therefore, must have taken place either at the close
of the Devonian or, at latest, early in the Carboniferous Period,
and was on such an extensive scale as to convert the greater-
part of New South Wales into dry land. For this mountain-
making period the name Kanimbla Epoch is suggested, and will
be used in that sense in this account of the geology of New
South Wales. The strata then folded now dip either to the east
or the west, the axes of the folds striking nearly north and south,
i.e., approximately parallel to the existing coast line. The
tangential thrust which produced this folding probably came from
the east.
The folding was accompanied by the intrusion of numerous
bosses and bathyliths of igneous rock. These rocks vary con-
siderably in composition, but are all more or less acidic, and
are, for the most part, granites and tonalites.
CHAPTER VIII.
THE CARBONIFEROUS PERIOD.
THE great mountain-making movement which closed the Devonian
Period converted the greater part of New South Wales into dry
land, the exception being the north-eastern portion, now known
as the New England Tableland. The greater part of this region
was covered by the sea during a considerable part of the Carboni-
ferous Period. In the southern and western parts of this area
extensive deposits of Carboniferous marine and fresh-water beds
occur, having their present southern and south-western boundary
approximately parallel to the railway line from Newcastle to
Narrabri, and at no great distance from it. The only known out-
crop of Carboniferous strata south of this line is the small inlier
surrounded by Permo-Carboniferous strata at Pokolbin.
The Carboniferous formation in New South Wales has been
subdivided into :—
(a) Upper Carboniferous, with Lepidodendron Veltheim-
ianum and Rhacopteris.
(b) Lower Carboniferous, with Lepidodendron Australe.
Lower Carboniferous. — Considerable thicknesses of strata, occur-
ring in the New England district, have been referred to the
Lower Carboniferous Period because of a supposed lithological
resemblance to a formation in Queensland, known as the Gympie
Series. Some of these strata have been traced across the border
into Queensland, and have been found to be continuous with some
of the so-called Gympie beds of that State. Certain of the strata
included in the Gympie series in Queensland are undoubtedly of
Carboniferous age ; some are probably of Permo-Carboniferous
age, while other strata which have been referred to this series are
very probably older than Carboniferous, perhaps in some cases as
old as Ordovician ; the absence of fossils in many localities makes
a correct determination difficult.
No marine fossils have yet been obtained from most of the
so-called Gympie beds in New South Wales, and their reference
to the Lower Carboniferous epoch, based entirely on lithological
resemblances to strata in Queensland, whose geological age is so
very doubtful, is not conclusive. As some of them have
Permo-Carboniferous strata resting unconformably upon them,
as, for example, at Ashford, near Inverell, these cannot, of course,
be younger than Carboniferous.
54
The fossil plant Lepidodendron Australe has been obtained
from some of these beds, but as this fossil is very common in
Devonian strata in other parts of the State, its occurrence, in the
absence of other fossils, might more justly be taken to indicate a
Devonian age for such beds. Until detailed surveys have been
carried out in this region no confident opinion can be expressed
as to the geological age of many of these so-called Lower Carboni-
ferous (Gympie) beds, but the balance of evidence is in favour of
a Devonian age for at least some of them. Quite recently some
of these so-called Gyrnpie beds of northern New England have
been shown to be of Permo-Carboniferous age.
Upper Carboniferous Series. — These are extensively developed
on the watersheds of the Karuah, Williams, and Paterson Rivers,
which are all tributaries of the Hunter River, draining the
rizmsul ?.»!* t_— £ ? . ff .CWit ?«rtl«al Brak
WILLIAMS X t0lkaan1tM^ ... r , PADDY* Hill
/ -x - vx rt KARUAH RIVER
CLARENCETOWH" * jv v\> "r\^. <~ir*£~~~ s
<t<"\ ' '\**.X \ \ \*">'\ ^ • ^s".' •""''*kCr' """ •••"•"' '" .' •V"r."^""-T- -~- ~_.^^</-,/,.. „...
""'A'""^ *"".V^'-. "VK v "^-V< •" •.'...--;- - ;•••/-.' -~j:y
Geological sketch section, from the Williams River, at Clarence Town, S.E. and K. to the Karuah River.
Fig. 25.
Section of Carboniferous Strata from Clarence Town to Karuah River. (Jaquet).
southern slopes of the New England tableland. These strata,
according to Mr. Jaquet, have a thickness of at least 19, 000 feet
They are partly marine and partly fresh-water in origin, and
consist of tuffaceous sandstones, claystones, limestones, conglome-
rates, cherty shales, with contemporaneous lavas and tuffs. Some
of the beds contain numerous marine fossils of undoubted Carbo-
niferous age, while in the fresh-water beds abundant plant remains
are found. The marine beds are well developed in the neighbour-
hood of Clarence Town, where they consist of fossiliferous shales
and sandstones, interstratified with coarse-grained arkose sand-
stones and tuffs ; limestones occur, but are not very thick, and,
when followed in the direction of their strike, pass rapidly by
insensible gradations into calcareous shales ; oolitic structure is
not uncommon. Fresh- water beds occur interstratified with the
marine beds, more or less, throughout the series, increasing in
55
importance towards the top, where they entirely replace the
marine beds. These fresh-water beds consist of shales and tufface-
ous sandstones, with thin seams of inferior coal. Throughout the
Upper Carboniferous epoch volcanicity was a marked feature, as
evidenced by the numerous thick beds of tuff' and lava which
occur over wide areas, interstratified with both the marine and
fresh-water sediments. In the Clarence Town and Paterson
districts no less than twelve successive lava flows occur, ranging,
individually, up to 500 feet or more in thickness (Fig. 25).
These volcanic rocks comprise rhyolites, rhyolite-glass, and
hypersthene-andesites with their corresponding tuffs. Some of the
latter are very coarse-grained, with blocks up to 3 feet in diameter
embedded in them ; they contain also water- worn fragments
of older rocks, and merge gradually into arkose-sandstones. At
Bulladelah one of the rhyolite flows has, by the action of thermal
springs, been altered into Alunite (hydrous sulphate of alumina
and potash) ; this has been quarried on a large scale for the
manufacture of alum. Another feature of possible economic
importance is the occurrence of numerous beds of Titaniferous-
Magnetite interstratified with the Upper Carboniferous Series.
These beds are of sedimentary origin, the Magnetite having
associated with it a variable proportion of quartz and felspar
grains, and they merge by insensible gradations into ordinary
tuffs and arkose-sandstones. This iron ore varies considerably
in composition, containing 36 per cent, to 50 per cent, of
metallic iron, 10 per cent, to 28 per cent, of silica, and 3 per
cent, to 16 per cent, of titanic acid. Professor David has
suggested that these beds have been formed by wave-action on a
sea-beach, mechanically concentrating the grains of magnetite
contained in the volcanic ash, so abundantly ejected during this
period.
At Pokolbin, some miles to the south of West Maitland, an
"inlier" of these Upper Carboniferous strata occurs, entirely
surrounded by strata of Permo-Carboniferous age ; here also
rhyolite lavas and tuffs are extensively developed. Further
outcrops occur also along the western edge of the New England
tableland, as for example at Crow Mountain, near Barraba, where
they consist of conglomerates, sandstones, shales, and limestones,
with which are associated rhyolites and rhyolite tuffs These
beds contain similar marine fossils to those at Clarence Town.
An extensive development of these acid lavas and tuffs occurs
further to the north, in a belt running parallel to and west of
the Northern railway line; they also underlie the Permo-Carbo-
niferous rocks in the Drake District. Marine Carboniferous
strata also outcrop on the coast from Port Stephens to Port
Macquarie.
56
CARBONIFEROUS LIFE.
(a) The Flora.— The Flora is well preserved, much more so
than that of the Devonian Period already described. It consists
entirely of Cyptogams, and includes the following species : —
Equisitacese. — Catamites radiatus.
Lycopodiaceae. — (?) Lepidodendron Australe, Lepidodendron
veltheimiamum , Lepidodendron volkmanniamum , Cyclostigma
Australe.
Filicacese. — Rhacopteris (Aneimites) inequilatera, Rhacopteris
intermedia, Rhacopteris septentrionatis, Archceopteris Wilkinsoni,
Cardiopteris pohjmorpha.
n?
Fig. 26.
Carboniferous Plants.
1. Archceopteris Wilkinsoni (Feist). 2. Lepidodendron Volkmannianum. 3. Rhacopteris
{Aneimites) inequilatera. 4. Calamites radiatus. 5. Cyclostigma Australe.
The geological range of Lepidodendron Australe is uncertain ;
that it was abundantly present during the Devonian Period is
unquestioned, but as to whether it lived on into the Carboniferous
Period is very doubtful. It has never yet been found associated
with the other members of the flora listed above, neither has it
Fig. 27.
A Carboniferous Trilobite.
Phillipsia dubia.
been found associated with marine beds containing a typical
Carboniferous marine fauna. The beds in which it occurs, as.
already pointed out, in the absence of
other fossils, might more reasonably be
referred to the Devonian Period. The
most abundant and characteristic fossil
plant of the Carboniferous Period is
Rhacopteris, and from it the flora as a
whole has been termed the Rhacopteris
Flora.
(b) The Fauna. — This, as far as we
know it, is entirely a marme inver-
tebrate fauna, consisting largely of
Brachiopods, Bryozoa, Gasteropoda,
Trilobites, and Corals, <fec. The Bra-
chiopods appear to have largely pre-
ponderated, but so little collecting
has been done that generalization is
difficult. The following is a list of the
more important genera and species so
far described : —
Actinozoa. — Amplexus, Zaphrentis Culleni, Lophophyllum
corniculum, Campophyllum columnare, Cyathophyllum Davidis,
Michelinia.
Crinoidea. — Actinocrinus, Periechocrinus.
Blastoidea. — Metablastus (?).
Bryozoa. — Fenestella, Polypora.
Brachiopoda. — Spirifer striata, Spirifer bisulcata, Orthis
(Rhypidomella) Australia, Orthis (Schizophoria) resupinata,
Leptcena rhomboidalis, Productus semireticulatis, Productus
punctatus, Productus com, Chonetes papilionacea, Orthotetes
crenistria, A thyris planosulcata , Cyrtinacarbonaria, Khynchonella
pleurodon, Strophalosia.
Pelecypoda. — Aviculopecten, Edmondia, Entolium, Pteronites.
Gasteropoda. — Euomphalus pentangulatus, Loxonema babbin-
donensis, Bellerophon.
Cephalopoda. — Orthoceras,
Trilobita. — Phillipsia^ Griffithides.
PROTOZOA. ^Neither Foraminifera nor Radiolaria appear to
have been abundant.
ACTINOZOA. — Corals, so far as is known, were only moderately
abundant ; most of those found built simple coralla and belong to
the Tetracoralla. The Tabulata, which was so strongly represented
in the Silurian and Devonian Periods, is here represented by one
genus only (Michelinia}.
58
ECHINODERMATA. — Crinoids, although less abundant than in the
Silurian Period, are still present in considerable numbers. This
formation contains the first and only recorded Blastoid from this
State.
Fig. 28.
Carboniferous Brachiopode.
1-3. Orthis (Schizophoria) resupinata. 4-5. Productus semireticulatus (Martin).
Leptcena analoga (Phillip). 7. Orthis (Rhipidomella) Australis. 8. Spirifer striata.
9. Orthotetes crenistria.
59
MOLLUSCOIDEA. — Bryozoa are numerous, and mo?t of those
found belong to the Fenestellidse, the most characteristic Palaeozoic
representatives of this class. Brachiopods are present in great
abundance and dominate all the other invertebrates ; the families
Stropkomenidce, Orthidce, Productidce and Spiriferidw are all
well represented. Rhynconella pleurodon, which lived in such
countless numbers in the Upper Devonian Epoch, still survived,
but is not abundant.
MOLLUSCA. — All the important classes were represented, but
were quite subordinate in importance to the Brachiopods.
CRUSTACEA. — The Trilobites still lingered on, but were repre-
sented by but two genera, both of which are small in size. This
unique and important group of Palaeozoic organisms became
extinct at the close of this period.
SUMMARY.
The crustal movements which closed the Devonian Period
probably converted the whole of New South Wales into dry land.
Most of it remained above the sea during the succeeding Car-
boniferous Period, but in the north-eastern part of the State a
subsidence began at the beginning of this period which allowed of
an extensive transgression of the sea taking place in that region.
Much detailed mapping of the Carboniferous formation will have
to be done, however, before the extent of this transgression will
be at all accurately known. Subsidence continued more or less
throughout this period, but repeated oscillations in this downward
movement brought about alternate marine and fresh-water
conditions, particularly towards its close. The sea contained
an abundant invertebrate fauna, while the land supported a well-
developed cryptogamous flora. This subsidence was accompanied
by intense and widespread vulcanicity, and from numerous centres
of activity in the north-eastern part of the State extensive lava
flows and deposits of volcanic ash were produced. These eruptions
continued at intervals throughout the greater part of the Carbon-
iferous Period, but were most pronounced towards its close.
CHAPTER IX.
PERMO-CARBONIFEROUS PERIOD.
A TYPICAL Permian formation, analogous to that of the Northern
Hemisphere, does not occur in Australia, its place being taken by
the so-called Permo-Carboniferous system. This name has been
applied in Australia to a thick series of marine and fresh-water
beds which follow the Carboniferous formation described in the
last chapter, and which are in turn overlain by fresh- water
Triassic strata. In New South Wales this Permo-Carboniferous
system has a maximum thickness of about 17,000 feet, and
includes both marine and fresh-water sediments. The marine
beds contain an abundant fauna which, taken as a whole, is
essentially different from that of the underlying Carboniferous
strata, and which has affinities with both the Carboniferous and
Permian marine faunas of the Northern Hemisphere. The
fresh-water beds, interstratified with these marine sediments,
-contain a fossil flora absolutely different from that of the under-
lying Carboniferous beds, and which displays a decidedly
Mesozoic aspect ; nevertheless it is quite different from that
preserved in the overlying Triassic strata.
The Permo-Carboniferous system is strongly developed in the
•eastern part of New South Wales, especially in what might be
called the central-eastern portion of the State. Here it occurs in
the form of a great basin extending from the coast to the
western edge of the Blue Mountain tableland, and from the
Illawarra district northwards to the southern edge of New
England tableland. Throughout the greater part of this area
the Permo-Carboniferous strata are overlain by Triassic beds ; a
continuous outcrop of them occurs, however, around the edge of
the basin, excepting along that part of the coast between
{Joalcliff and Lake Macquarie. In addition to this main basin,
Permo-Carboniferous strata are extensively developed along both
the eastern and western flanks of the New England tableland,
but are quite absent in the south-eastern and in the western
parts of the State.
Where the Permo-Carboniferous formation comes in contact
with the underlying Carboniferous, as in the Hunter River
district, the two systems seem to be separated by a slight uncon-
formity, and there is frequently considerable overlap of the en tire
strata of the Permo-Carboniferous on the Carboniferous, so that
in many places the basal beds are entirely concealed from view
by the later beds.
61
The following subdivison of the Permo-Carboniferous system
is used in New South Wales : —
Maximum thickness.
Upper Coal-measure Series ... ... 1,500 feet
Dempsey Series ... ... ... ... 3,000 „
Middle Coal-measure Series ... ... 1,700 ,,
Upper Marine Series ... ... ... 6,400 ,,
Lower Coal-measure Series ... ... 300 „
Lower Marine Series ... ... ... 4,800 ,,
Total ... 17,700
(A). — THE LOWER MARINE SERIES.
The Hunter River District. — This, the lowest subdivision of
the Permo-Carboniferous system, has its greatest development in
the Hunter River district, where it attains a maximum thickness
of about 4,600 feet. The following strata occur (in descending
-order).
Thickness.
Parley stage —
Marine sandstones ... ... ... ... 800 feet
Ravensfield sandstones ... ... ... 15 ,,
Lochinvar stage —
Tuffaceous and calcareous shales and
cherts (with abundant Bryozoa and
Foraminifera) ... 700 „
Amy gdaloidal basalt flow 100-500 „
Harper's Hill sandstones and conglome-
rates (passing into andesite in places) ... 200 ,,
Tuffaceous shales (with glacial erratics
and two contemporaneous basaltic lava
flows) 2,500 „ .
Massive sandstones, with plant remains... 50 „
Glacial beds with numerous striated
boulders 200 „
The basal beds consist of shales and sandstones containing
numerous ice-striated pebbles and boulders. These are not in
any sense boulder - clays or till, but are ordinary sediments
into which, during their deposition, glaciated pebbles have been
dropped by floating ice. It might be mentioned here that this is
the probable origin also of the striated boulders and erratics
which occur on several higher horizons in the Permo-Carboniferous
system in New South Wales. These glacial beds grade upwards
into massive sandstones containing plant remains. Then follows
a series of shales with occasional glacial erratics, and containing
62
abundant marine fossils. These beds are about 2,500 feet thick,
and include several contemporaneous lava-flows. The tuffaceous
sandstones and conglomerates which come next are typically
exposed at Harper's Hill and in the railway cuttings at Allandale,
They contain abundant fossil shells, some of which, such as
Eurydesma, Keenia, Aviculopecten, &c., attain a considerable size.
In close association with the Eurydesma beds occur andesitic lava-
flows and tuffs, typically developed at Blair Duguid, to the south
Fig. 30.
Photograph of a Glacial Erratic (Granite) occurring in Upper Marine Strata,
near Branxton, New South Wales. (David.)
of Allandale. The Harper's Hill beds are followed by a series of
basic lavas and tuffs ranging from 100 to 500 feet in thickness,
the latter containing fossil plants. This volcanic series is well
exposed at Mount View, still further to the south of Allandale,
and is overlain by about 700 feet of soft calcareous shales, some
of which are crowded with exquisitely preserved fossil Bryozoa
(Fenestella, Polypora, Stenopora) and Foraminifera (Nubecularia f
&c.). These calcareous shales are more or less tuffaceous ; they
close the Lochinvar stage and are succeeded by the Ravensfield
sandstones, the basal beds of the Farley stage. This bed of
63
sandstone, although not more than 15 feet in thickness, is so
persistent, that in one place it can be traced for a distance of
20 miles ; it contains, in places, numerous fossils, the most
characteristic of which are the genera Goniatites and Edmondia.
Some beautiful starfish are also obtained from this stratum. The
remaining beds of the Farley stage have a thickness of about
1,000 feet, and consist mainly of sandstone, in some of which
marine fossils are very abundant.
Near Raymond Terrace the Lower Marine series includes some
fresh water beds which occur at about the same horizon as the
Eiirydesma beds of Allandale. These contain abundant fossil
ferns (Gangamopleris) and a coal seam about 10 feet thick, known
as Garrett's Seam.
The Northern Rivers District. — Extensive outcrops of Lower
Marine strata are known to occur at various localities between
the Hunter River and the Queensland border, notably on the
watershed of the Macleay River, and about the headwaters of the
Upper Clarence River. The former occurrence extends from the
coast at the mouth of the Macleay River, westward, to the eastern
fall of the New England tableland, but very little however is at
present known as to its real extent. In his account of the Drake
Gold-field, Mr. E. C. Andrews has described the occurrence of
Lower Marine strata, associated with which is an extensive series
of andesitic lavas and tuffs, the whole resting unconformably upon
an older series of acid lavas and tuffs ; the latter are, probably, of
Carboniferous age. The Per mo-Carboniferous strata in this region
have been extensively folded, and have been intruded by at least
two separate granite intrusions.
Mr. J. E. Carrie has quite recently proved the existence of
similar Lower Marine strata in the Emmaville district.
Overlapping of the Lower Marine Beds. — In the Hunter River
district, where the northern edge of the Permo-Carboniferous
basin occurs, the Lower Marine beds, as well as the Lower Coal
Measures which follow them, dip south and west under the later
members of the system, but fail to reappear again, either on the
southern or the western edges of the Permo-Carboniferous basin.
Both series, therefore, have evidently been overlapped by the
Upper Marine series, which, in these regions, rest directly, and,
at the same time, unconformably, upon strata of Devonian age,
(see Fig. 53). Just how far to the south and south-west this
overlap takes place is unknown.
(B). — THE LOWER COAL-MEASURE SERIES.
Hunter River District. — In this district the lower Coal Measures
are generally referred to as the Greta Coal Measures, and have a
thickness of from 150 to 250 feet. They comprise fresh-water
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66
shales, sandstones, and conglomerates, and contain two important
coal seams. The lower coal seam is known as the Homeville
Seam ; it varies from 3 to 11 feet in thickness and contains a
hard bituminous coal. la the South Greta Mine the base of
this seam consists of kerosene shale. The upper seam, called the
Greta Seam, varies from 14 to 32 feet in thickness, and is
undoubtedly the finest seam of coal yet found in Australia. The
coal is very hard, bright, and bituminous, and shows remarkable
uniformity in composition throughout the district in which it
occurs ; it is of excellent quality for steam, gas, and household
purposes. In some places it merges into a cannel coal, and
Dccasionally into kerosene shale. IP the sandstones and shales
forming the roof of this seam stems of trees of considerable size
occur.
A bed of conglomerate, containing white and green pebbles,
which overlies the bottom seam of coal, forms a very characteristic
" persistent horizon " which has been very useful in mapping the
outcrop of these coal-measures. On the eastern side of the anti-
cline a continuous line of collieries extends from West Maitland
to Cessnoekj nearly all of which have been opened up during the
past few years As these coal seams are not horizontal, but dip
at angles ranging up to 50°, or even more in some places, their
depth below the surface must rapidly increase in the direction of
the dip, when the latter is considerable. Using a limit of 4,000
feet as the vertical depth at which coal seams can be profitably
worked, Professor David has estimated that these two seams
exist at a workable depth over an area of 158 square miles, and
contain a gross available quantity of 1,893,000,000 tons of coal.
A rich fossil flora has been preserved in the shale beds, and
includes the genera Gangamopteris, Glossopteris, Sphenopteris,
Noeggerathiopsis, and Dadoxylon ; of these the first is the most
abundant.
New England Tableland. — The Lower Coal Measures extend
northwards along the western fall of the New England Tableland
toward the Queensland border. They are known to outcrop in
the Parish of Tangorin (County of Durham), where they appear
to have been much disturbed. From there the outcrops trend
north-westwards past Muswellbrook, where a fine seam of coal
15 feet in thickness is now being opened up. At Wingen the
Greta coal seam is on fire, and has been burning for probably
1,000 years or more. Still further to the north at Ashford, near
Inverell, a long narrow coal-field occurs about a quarter of a mile
wide and extending northward nearly to the Queensland border.
Here the Lower Coal Measures have a thickness of over 400
feet, and include a fine coal seam 27 feet in thickness and of good
quality. These beds have a dip of 40° and rest unconformably
67
upon a series of highly inclined slates which have been referred
to the Carboniferous Period. It is quite possible that these
latter beds are of Devonian age. The fossil plants associated with
the coal seam here are similar to those of the Greta Series. At
Wilson's Downfall, near Tenterfa'eld, deposits of graphite occur,,
associated with slates and tuffs, all of which have been intruded
by granite. The graphite deposit has resulted from the alteration
of a dirty coal seam by the granite inclusion. These beds
probably belong to the Lower Coal Measures.
Illawarra District. — Fresh- water beds containing coal seams
have been found underlying the Upper Marine Series at several
localities immediately to the south of the Shoalhaven River.
They vary from a few feet up to 150 feet in thickness, and rest
unconformably upon tilted Devonian strata. Near the head of
the Clyde River these bede outcrop at an altitude of 1,300 feet,
and include two coal seams, the upper one of which is about
5 feet thick (including bands). Thin layers of kerosene shale
occur near the top of this seam. Similar fresh- water beds occur
elsewhere in the district, but they have no great thickness, and
the coal seams are either poor or absent. The formation, as a
whole, appears to occur in the form of small isolated basins
rather than to be continuous over any considerable area, and, as-
coal-measures, they appear to have very little commercial value.
These measures have been correlated with the Lower Coal
Measures of the Hunter River district, but it is very doubtful if
they are co-extensive with them.
(C). — THE UPPER MARIXE SERIES.
This series extends over a wider area, perhaps> than any of the
other subdivisions of the Permo-Carboniferous System in New
South Wales, and outcrops all around the edges of the main coal
basin. A description of its occurrence in the Northern, Southern,
and Western Coal fields will serve to give a general idea of the
main features.
Hunter River District (Northern Coal-field).- — The Upper
Marine Series here attains a maximum thickness of 6,000 feet,,
and consists of the following strata : —
Orinoidal Stage. feet.
Cha?nomya Beds ... ... ... ... ... 100
Crinoidal shales 2,900
Muree Stage.
Conglomerates and sandstones ... ... ... 400
Branxton Stage.
Marine shales, sandstones, and conglomerates
(with erratics) ... 3,000
68
(a) The Branxton Stage. — These beds consist mainly of sand-
stone and shale, in which marine fossils, particularly the
Fenestellidse family of the Bryozoa, are very abundant;
glacial erratics are also very numerous. These latter-
range up to 5 tons in weight, generally consist of granite,
and some of the smaller ones are distinctly striated. One of
these erratics is shown in Fig. 30. The position in which it
rests, poised on edge, and the way in which it seems to have
indented the underlying shales, shows that it was probably
dropped from floating ice into a bed of soft marine mud and left
standing in the position in which it is now seen. One of the few
fossil corals which occur in the Per mo-Carboniferous strata, viz.,
Tracliypora, occurs abundantly near the top of this stage.
(b) The Muree Stage. — The lowest stratum is a calcareous
conglomerate, containing numerous small and occasionally large
glacial erratics and an abundance of marine fossils. Its hardness
and resistance to weathering causes it to make a bold outcrop.
This bed is usually about 3,000 feet above the Greta Coal
Measures, and passes upward into a series of massive calcareous
sandstones about 400 feet in thickness, in which a small
brachiopod (tStrophalosia) occurs in great numbers.
(c) The Crinoidal Stage. — The strata on this horizon are
mainly shales, and, as the name implies, contain abundant
remains of Crinoids. The thickness varies from 1 ,500 to 3,000
feet, and they terminate upwards in beds of hard cherty shales
called the Choenomya Beds, on account of the number of pele-
cypods of that name which they contain.
The Lithgoic-Capertee District (Western Coal-field). — The
Permo-Carboniferous formation here has a total thickness of from
800 to 1,600 feet as compared with a thickness of over' 15,000 feet
in the Hunter River district. The Lower Marine Series and the
Lower Coal Measures are entirely absent, while the Upper Marine
Series-, the oldest subdivision represented, rests unconformably
upon highly tilted Lower Palaeozoic strata. It seems evident,
therefore, that this region was dry land undergoing denudation
during the time the absent members of the formation were being
deposited elsewhere. A fairly rapid subsidence toward the later
part of the Upper Marine epoch, however, allowed the sea to
transgress much farther westwards than had been the case in the
earlier part of the period. That the subsidence was fairly rapid
is indicated by the thick coarse conglomerates which occur at the
base of the Upper Marine Series in the western district. This
is a typical basal conglomerate produced by the waves working
over the regolith as the eea advanced on the land. The boulders
in it are mainly granite and quartzite, derived from the older
rocks upon which the conglomerate rests ; the material cementing
69
the boulders together is frequently granite sand (arkose con-
glomerates). These conglomerates are of considerable thickness,
with increasing coarseness towards the lowest stratum, where
occasional boulders of quartzite several tons in weight occur. It
has been suggested that these large boulders have been trans-
ported by floating ice, but as this is a typical littoral deposit laid
down along an old shore-line, and as the boulders appear to have
been derived from the underlying and adjacent older strata, this
explanation hardly seems necessary. It is true that undoubted
glacial erratics exist in the Upper Marine strata of the Newcastle
district, but they occur on what is probably a lower horizon.
Above the conglomerates occur alternating beds of shale, sand-
stone, and conglomerate, the shales predominating as the top of
the series is reached : here thin bands of dolomite and earthy
limestone also occur.
The Upper Marine strata in these western districts are singu-
larly poor in fossil remains, and such as do occur are found in the
lower beds only. The following forms have been identified : —
M.artiniopsis subradiata. Gonularia inornata.
Spirifer vespertilio. Goniatites micro mphalus.
Spirifer tastnaniensis. Fenestella fossula.
Productus brachythwrus. fitenopora tasmaniensis.
Moeonia carinata. Aviculopecten tenuicollis.
Strophalosia Clarkei. Platyschisma.
In some localities the basal conglomerates are auriferous ; at
Tallawang, and at Gough's Valley, near Gidgong, the auriferous
conglomerates have been mined, and have yielded from 1 to 15
dwt. of gold per ton, while nuggets weighing up to 5 oz. have
been obtained. The gold, which was coarse and waterworn, had
undoubtedly been shed by reefs in the underlying Lower Palaeozoic
formations at the time the conglomerates were being formed, but
its* distribution in the conglomerates was very patchy.
The South-Western Coal-fidd. — The Upper Marine Series outcrop
in the valleys intersecting the tableland in the neighbourhood
of Bundanoon, &c., and consist mainly of sandstones and shales
containing abundant marine fossils. Farther south at Tallong
the formation, which ranges up to 400 feet in thickness, consists
mainly of conglomerates with thin bands of fossiliferous sandstone.
The pebbles in the basal conglomerates have been derived from
the underlying older Palaeozoic rocks, and include graphitic slates,
quartzite, &c.
The I/lawarra District. — Here, as has already been shown
with regard to the Western Coal-field, the Lower Marine Series
is absent and the Upper Marine Series, where the base is visible,
rests unconformably upon truncated Lower Palaeozoic strata.
Near the southern edge of the Permo-Carboniferous basin, however,
11
1.1
5 t>
6 It
o PQ
o _o
71
fresh-water beds, such as those at the Clyde River, tmderly
the Upper Marine Beds, but, as already pointed out, to a very
limited extent. Upper Marine strata outcrop along the coast
from Wollongong to as far south as Ulladulla. North of the
Shoalhaven River they are overlain by the Upper Coal Measures,
but south of it they occupy the surface of the tableland over a
very considerable area. When the tableland is intersected by
the river valleys, these beds have been removed, and the under-
lying Lower Palaeozoic strata exposed. The Upper Marine Beds,
which here have a maximum thickness of about 3,000 feet, have
been subdivided as follows : —
Thick.
Volcanic Series — Crinoidal shales ... ... 1,000 feet
Nowra grits ... ... ... ... ... 250 ,,
Wandra-Wandrian sandstone ... ... 550 „
Conjola Beds 1,400 „
(a) Conjola Beds. — These occur at the base of series and rest
either upon the underlying fresh-water beds, or unconformably
upon Devonian or older strata. They consist of conglomerates,
grits, and pebbly sandstones. Large boulders of granite, quartz
porphyry, and quartzite occur both in the basal conglomerates and
the overlying beds of coarse sandstone. Marine fossils are fairly
common in these beds, particularly the genus Mceonia (a pelecypod).
(b) The Wandra- Wandrian Sandstones. — These outcrop strongly
along the road from Nowra to Milton, but possess no features of
special interest.
(c) The Nowra Grits. — These are the gritty sandstones which
outcrop around the township of Nowra and along the banks of
the Shoalhaven River. They resemble the Muree rock of the
Hunter River district both in lithological character and in their
contained fossils.
(d) Crinoidal Beds. — These consist mainly of marine shales and
sandstones. In the Kiama district their place is taken largely
by the Volcanic Series. The lower beds contain crinoid stems in
abundance, while in the Gerringong district the strata are literally
crowded with fossils, due probably to the rapid killing off of the
marine organisms by the showers of fragmental material which
now began to be ejected by volcanoes. The richness of this marine
fauna is shown in the following list of fossils : —
Upper Marine Fossils from Gerringong.
PLANTS. — Coniferous wood (Dadoxylori), Fucoid remains.
CRINOIDEA. — Tribrachiocrinus corrugatus, Phialocrinus Step-
hensi.
BRYOZOA. — Stenopora crinita, K. Tasmaniensis, Fenestella
fossula, F. internata, Polypora, Protoretepora ampla.
72
BRACHIOPODA. — Lingula ovata, Productus brachythcerus, Die-
lasma hastata, Martiniopsis subradiata, Martiniopsis oviformis,
Spirifer vespertilio. S. tasmaniensis, S. Clarkei, >S. Strzeleckii,
Spiriferina duodecimcostata.
PELECYPODA. — Deltopecten subquinquilineatus, D. leniusculus,
Merismopteriamacroptera,Mcecniaelongata,M. valida, M. carinata,
Chcenomya Etheridgei, C. Mitchelh, Astartila polita, Notomya
securiformis, Stutchburia costata, Nuculana Darwini.
GASTEROPODA. — Playschisma oculum, Ptycomphalina Morris-
siana, Mourlonia Strzeleckiana, Murchisonia verneuliana.
PTEROPODA. — Hyolithes lanceolata, Conularia inornata.
CEPHALOPODA. — Goniaiites micromphalus, Orthoceras.
Vertical Scale
Cambewarra
Mtn.
Jamberoo
• About 13 Miles - >-Mtn.?l30ft
Robertson Basalt
2000 Ft
1000 ft
r Nowra_- -Berry; ^ - x < v < *
/. Howra •
i4 Grits, '.
and Ardl/jceous Sandstones
Wa/l&ya Do/erite
Nepheline Syenite
Saddleback Doieriie
West/ey Park Tuffs
Argillaceous Sandstones and Shales
Fig. 36.
ession of 1
[iama District. (Jaquet and Card.)
Diagrammatic Section showing the succession of the Permo-Carboniferous Volcanic Series
in the Ki
(e) The Volcanic Series. — From the Cambewarra Mountains to
Port Kembla the upper portion of the Upper Marine formation
consists entirely of lavas and tuffs; these have in the neighbour-
hood of Kiama a maximum thickness of about 1,000 feet. To
73 -
the north, south, and west the volcanic series gradually thins out
and gives place to ordinary marine sediments. From the first
centre of eruption, which seems to have been in the neighbourhood
of Kiama, a great series of basic lavas and tuffs was ejected and
deposited on the surrounding sea-bottom. A second centre of
eruption then developed further to the south, in the direction of
Cambewarra, which produced trachytic lavas and tuffs ; these in
turn were followed by basic lavas. Vulcan icity was resumed on
74
a smaller scale in the Upper Coal-measure epoch with a further
outpouring of basic lavas. The section in Fig. 36 shows this
volcanic series, including the lavas of the coal- measure.
1. Westley Park Tuffs. — These are about 40 feet in thickness ;
followed downwards, they merge imperceptibly into marine shales
and sandstones. They contain abundant marine fossils, while
ejected volcanic blocks up to a ton or more in weight are not
uncommon.
75
2. Blowhole Flow. — This outcrops at sea-level at Kiama, and
extends southwards as far as Gerringong. This flow is a typical
basalt, and is about 140 feet in thickness.
3. Kiama Tuffs. — These overly the Blowhole flow, and have a
thickness of 120 feet. They are basic in composition, are fine-
grained and well stratified. Bands of lapilli occur at intervals.
Their basic composition results in a rich reddish-brown colour on
weathering.
4. Bumbo Flow. — This is a very extensive sheet of lava, and
ranges from 30 to 500 feet in thickness. It is strikingly columnar,
some of the columns attaining a height of 50 or 60 feet and a
diameter of 8 feet.
The rock is a basalt, which approaches andesite in chemical
composition and is markedly porphyritic in texture, the phenocrysts
of Labradorite being as much as 1 \ inches in length. The rock
also contains a very small percentage of native copper. The flow
has been extensively quarried in the neighbourhood of Kiama
for railway ballast and for road-making, its perfect columnar
structure being of material assistance in quarrying.
5. Jamberoo Tuffs.— These are trachytic in composition, and
have a maximum thickness of over 600 feet. They extend from
Cambewarra to as far north as Jamberoo, and overlap the basic
flows and tuffs already described.
6. Saddleback Flow. — This is a basalt, and covers a less exten-
sive area than the other lava flows of the district ; it has a thick-
ness of about 60 feet.
7. Cambewarra Flow. — Excepting perhaps the Bumbo flow,
this is the largest and most extensive flow in the district. It has
a maximum thickness of 600 feet, and extends from Stockyard
Mountain (north-west of Kiama) to the southern edge of the Cam-
bewarra Range, a total distance of 22 miles. It is a trachyte, and
consists mainly of Orthoclase and Plagioclase, with a subordinate
amount of Augite. The chemical analysis of these lavas is given
on page 168.
(D). — THE TOMAGO SERIES AND THE DEMPSEY SERIES.
The Middle Coal Measures.
Lying between the Upper Marine Series and the Upper Coal
Measures in the Newcastle-Maitland area of the Hunter River
district there is a considerable thickness of fresh- water beds. The
lower part of this formation contains several workable coal seams,
and has been called the Tomago or East Maitland Coal Measures
76
while the upper part, which is not known to carry any coal seams,
is known as the Dempsey Series. Neither of these are known to
occur in any other district.
(a) The Tomago or East Maitland Coal Measures. — These are
fresh- water beds, varying from 600 to 2,000 feet in thickness,
and include the following strata : —
Four-mile Creek Beds — feet.
Conglomerates ... ... ... ... 20
Sandstone and shales ... ... ... 58
No. 1 Coal Seam (top searn) ... ... 4J
Sandstones ... ... ... ... ... 68
No. 2 Coal Seam 7
Shales with (Glossopteris] ... ... ... 5
No. 3 Coal Seam ... ... ... ... 6
Shales and sandstones (with two thin
coal seams) ... ... ... ... 38
Buttai Beds-
Sandstones and shales ... ... .... 220
Rathluba Beds —
Rathluba Coal Seam ... ... ... H
Shales, &c 82
Morpeth Coal Seam ... 4J-8
Shales, sandstone, &c. ... ... ... 94
The coal seams are very variable in thickness, frequently split-
ting, and in places show marked evidence of contemporaneous
erosion, The coal is friable and inferior to that obtained from
the Lower and Upper Coal Measures. The aggregate thickness
of coal is about 40 feet, of which about 20 feet has been proved
to Tbe workable.
(b) The Dempsey Series. — This is a series of fresh-water beds,
shales, and sandstones, about 2,000 feet in thickness, lying
between the East Maitland Coal Measures and the Upper
Newcastle Coal Measures. They appear to contain no coal
seams, and possess no features of special interest.
(E).; — UPPER -COAL MEASURES.
:This,' the topmost subdivision of the Permo-Carboniferous
system, extends over nearly the same area as the Upper Marine
Series, and, except in parts of the Hunter River district, directly
succeeds : the latter formation. It is the most important and
extensive coal-bearing formation in Australia. The Upper Coal
77
Measures in the Newcastle district include the following
strata : —
feet.
Wallarah coal seam ... ... ... ... 5
Shales ... 6
Conglomerates ... ... ... ... ... 120
Great Northern coal seam ... ... ... 14
Tuffaceous shales (with fossil trees) ... ... 80
Coriglo rne rates ... ... ... ... ... 45
Shales, sandstones, and cherts ... ... 54
Upper Pilot coal seam
Shales, tuffs, and cherts ... ... ... 33
Lower Pilot coal seam ... ... ... 5
Conglomerates (with current bedding) . . . 200
Cardiff coal seam (with bands) ... ... 16^
Shales, &c. ... 30"
Burwood coal seam ... ... ... 13^
Shales and cherts ... ... ... ... 35
Nobbys coal seam . . ... ... ... 6
Shales ... 40
Dirty coal seam ... ... .. ... 7
Shales 50'
Yard coal seam
Shale and sandstones ... ... ... . . 200
Borehole coal seam ... ... ... ... 6-20
Waratah sandstone ... ... ... ... 30
Shales, &c. (with two small coal seams) ... 170
Total thickness -1,221
It will be seen that the Newcastle Coal Measures include ten
important coal seams, as well as several smaller ones. Of these,
the Borehole seam has received the greatest attention from the
coal miner, and is worked at nineteen distinct collieries. It
varies from 4^ to 20 feet in thickness, and in places splits into
two seams, the upper division being then known as the Young
Wallsend Seam. The upper seams correspond with those in the
Illawarra Coal Measures, and are being worked in several
collieries. The two Pilot seams apparently coalesce in a south-
westerly direction, and form the Australasian Seam, which
(including clay bands) has a thickness of 50 feet, and is the
thickest coal seam in New South Wales ; only the lower 7 feet of
the coal is mined.
The aggregate thickness of workable coal in the seams of the
Newcastle Coal Measures is from 35 to 40 feet.
The coals are fairly hard ; they include both splint and bitu-
minous coals, and the quality fe excellent for gas-making arid:
78
steaming purposes. The strata with which these coal seams are
associated consist of conglomerates, sandstones, shales, and cherty
tuffs. Conglomerates are strongly in evidence in the upper
part of the series, individual beds ranging up to 200 feet in thick-
ness. A feature of special interest with regard to these conglome-
rates, is that they show strongly marked current bedding, the
laminae in many cases dipping from the ocean towards the land ;
this would seem to indicate that the land which supplied the
36 feet Greenish-grey shales passing into red shales like the chocolate
Narrabeen stage.
10 feet ] Conglomerate weathering ochreous brown.
10 feet Chiefly shales, greenish-grey to ochreous and red.
2 feet Hard whitish sandstone. The basal bed of the Triassic rocks.
2 feet Coal much weathered. This is the Wallarah or Bulli Seam.
1 inch Brown shale, with Vertebrana.
linch Coal.
8 inch Shaly coal, with bands of brown shale.
3 feet Dark grey shale, becoming lighter in colour downwards.
1 foot Red shale like chocolate shale.
1 foot Fine-grained sandstone.
45 feet Coarse conglomerate.
20 feet Conglomeratic sandstone.
of the N
Fig. 39.
Cliff Section, Moon Island, south of Newcastle, showing junction of Triassic Rocks
and Upper Coal Measures. (David.)
pebbles for the building up of these beds lay to the east of the
existing coast. The shales contain an abundance of fossil plants,
among which the genus Glossopteris is particularly plentiful.
Remains of fossil insects (Mayflies) also occur on some horizons.
The beds of chert which occur at frequent intervals, particularly
between the Nobbys and Burwood coal seam, have been shown to
consist of minute broken fragments of felspar crystals, inter-
spersed with volcanic ash. These beds then, fine-grained as they
are, are really tuffs ; excellent samples of them may be seen in
the cliff sections adjacent to Newcastle.
79
Origin of the Coal. — Professor David, in his description of the
Pilot seam and the adjacent strata, makes the following remarks
regarding the origin of the coal : — " No more impressive evidence
can be imagined as to the origin in situ of our coal seams than
that afforded by this beautiful section. (See Fig. 40.) The beds
of chert which separate the Upper Pilot seam from the Lower-
Coarse conglomerate.
Horizon for 14-foot (Great Northern) coal seam.
?il trees on horizon of the Awaba Trees of Fennel Bay.
80 feet, chiefly tuffaceous grey shales, with occasional cherty bands,
and some perished coal, perhaps, on horizon of Fassifern Seam
45 feet conglomerate, passing downwards into pebbly
sandstone, with drift trees fossilised in ironstone
to 3 ieet dark grey shale.
40 feet hard, bluish-grey sandstone.
Bottom of Government Quarry.
12 feet cherts and Carbonaceous shales.
8 feet 9 inches coal and bands, Upper Pilot Seam
6 feet 5 inches soapy shales and hard cherty rock.
8 feet speckled tuft's, well stratified sandstones, an
cherty shales.
19 feet cherts and grey shales.
."> feet, Lower Pilot Seam, w>al and shale band
:H feet sandstone, passing downwards into
hard, line conglomerate.
Fig. 40.
Section of Upper Coal Measures, Government Quarry, Swansea. (David.)
are traversed by numerous vertical stems of large trees, now
converted into chalcedony These can be traced downwards
almost from the lioor of the Upper seam through a thickness of
from 20 to 30 feet of chert into the roof of the Lower seam. As
they are traced downwards into the top layer of the coal of the
Lower Pilot seam, the substance of the fossil trees changes
quickly from chalcedonic-quartz into a form of hydrocarbon. It,
is a fact most obvious, even to the most casual observer, that:
80
these trees are all in situ in the roof of this lower coal seam, and
that their stems and roots have become partly absorbed into the
substance of the coal. The trees were about 5 yards apart from
•centre to centre, and their diameter varies from 10 to 15 inches.
In the floor of both the Upper and Lower Pilot seams there are
great numbers of more or less vertical roots of vertebraria [the
rhizome of Glossopteris. — C.A.S.], while the layers of black shale
between the beds of coal abound in Glossopteris [a fossil fern. —
20 to 30 feet. Coarse sandstones and fine conglomerates.
Fossil trees.
20 feet (about). Dark-grey clay shales and sandstones.
6 feet Sandstone.
10 feet Cherts and cherty shales.
13 feet Burwood Coal Seam.
16 feet Dark-grey clay shales.
Thin coal seam.
10 feet Fine greyish-white sandstone.
Sea level.
10 feet Clayey sandstones.
^ 10 to 12 feet Cherts.
5 to 6 feet Nobbys Coal Seam.
Fig. 41.
Cliff Section, Portion 30, Parish of Kahibah, south of Newcastle (David). This,
with the two preceding sections, gives a nearly complete succession of the Upper
Coal Measures as seen outcropping along the coast south from Newcastle.
C.A.S.], and the black fireclay bands are full of mother-of-coal
and sporangia (seed vessels). It is quite evident that we have
here to deal with an ancient fossil forest which marked the final
stages in the evolution of a huge peaty swamp in Permo-Carboni-
ferous times. This forest was formed of closely-packed, tall,
coniferous trees, rooted on the surface of thick peat. It is clear,
then, that in this seam, as in the case of all Newcastle seams,
the woody material which went to form the coal actually grew on
the spot where the seams are now found.
81
The past geological history of this part of the coal-field may
probably be read as follows : — Along a wide coastal plain there
was a development of plant growth in shallow marshes, the pre-
dominant type of plants at first being Glossopteris and Sphenopteris.
This growth of lowly-organised plants like ferns was followed later
by a spread of forest trees."
Rix's Creek Coal-field. — The Upper Coal Measures which occur
at Rix's Creek, near Singleton, have a thickness of upwards of
1,000 feet and dip to the west. Bores put down in these
measures at Ravensworth penetrated twelve (12) seams of coal,
the aggregate thickness of coal being 86 feet. These coal
measures are probably the equivalent of the Newcastle Coal
Measures.
The Curlewis-Gunnedah Coal-field. — The same coal seams
extend in a westerly direction to Gunnedah, where they
have been worked to a small extent. The following succes-
sion of strata have been described from this locality by
Mr. J. E. Carne.
Thickness.
feet.
Tertiary (3) Dolerite Flow 200
{' Hawkesbury Stage 130
f Chocolate shales 3
Narrabeen Stage -< Sandstones 40
( Conglomerates 90
( Sandstones 50
Coal seam 12-15
Shales, sandstones, and conglome-
rates 100
Permo-Carboniferous - Upper^j g^erty Tales' :.' 50
Coal Measures. Sandstone, conglomerate, and
shales 58
Coal seam 6
j Shales and sandstone (unknown
I thickness)
The Mnrrurundi District,. — Here the Upper CoalMeasure Series
consist mainly of lavas and tutf's ; interstratified with them, how-
ever, there are some fresh- water beds.
The rhyolites and rhyolite tutf's which occur at the base of the
series are probably of Carboniferous age. The fresh-water beds
are about 100 feet thick, and contain at least one coal seam in
which an important deposit of Kerosene Shale occurs, and which
is now being opened up. The lavas and tuffs associated with
these fresh-water beds are basic in composition, and are upwards
of 1,200 feet in thickness.
83
The Western Coal-field. — This coal-field occurs along the western
edge of the Permo-Carboniferous Basin, the coal measures
outcropping beneath the Triassic strata along the sides of the
valleys on the western edge of the Blue Mountains Tableland,
from Lithgow northwards to Gunnedah. South from Lithgow
the outcropping edge of the coal-basin trends south-west past
Burragorang to the South-western Coal-field.
The Lithgow Coal Measures are the equivalent of the Newcastle
and Bulli Coal Measures, and in the Lithgow district have a thick-
ness of about 480 feet ; northwards the thickness gradually in-
creases, until at Talbragar, and in the North-western Coal-field
generally, a thickness of about 1,200 feet is reached. The base
of the coal measures in the Lithgow district is marked by a bed
of conglomerate about 50 feet in thickness called the Marangaroo
Conglomerate ; the remaining strata consist of shales and sand-
stones, with a few thin bands of conglomerate and cherty tuffs.
Seven coal seams are known to occur, three of which are of com-
mercial importance. Of these the lowest (Lithgow seam) is the
most extensively worked, seven collieries operating on it at
Lithgow, and five collieries at Wallerawang and Cullen Bullen.
The next seam (sixth seam), which is 60-80 feet above the
Lithgow seam, is worked to some extent at Portland, Cullen
Bullen, and Wallerawang, and is somewhat similar in composi-
tion. The " Top " or " Katoomba " seam occurs at the top of the
series, immediately below the Triassic strata. This seam is
apparently identical with the " Bulli" seam of the Illawarra
district and with the seam now being worked in the Balmain
Colliery (Sydney). It has been mined for coal at Hartley Yale
and elsewhere, but its importance is due mainly to the occurrence
in it of a band of kerosene shale, varying from 2 feet to 6 feet in
thickness, which has been extensively mined at Hartley Yale,
Katoomba, &c. The nature and origin of kerosene shale will be
referred to later. The shales associated with the coal-measures
are very suitable for the manufacture of brick, pottery, stoneware,
and fire-brick", and are being extensively used for this purpose
at Lithgow. The fossil flora preserved in these shales is similar
to that found in the corresponding strata in other districts,
and includes Olossopteris, Vertebraria, tiphenopteris, Phyllotheca,
Brachyphyllum, Dadoxylon, and the Nce.ggerathiopsis. In the
cherty tuffs near Lithgow, these plants are particularly well
preserved.
The South- Western Coal-field. — This occurs adjacent to the Main
Southern Railway Line from Mittagong to Tallong. Here the
main streams have cut down their gorges through the Triassic strata
which forms the surface of the Tableland, and have exposed the
underlying upper coal-measures. These range up to 200 feet in
84
thickness and include several coal seams. At Tallong, on the
southern edge of the basin, conglomerate and sandstones pre-
dominate. Here the coal is of a very poor quality, as might have
been expected, since it was produced at the very border of the coal
swamps, and therefore subject to contamination by mechanical
sediments. Here also the leaves of Nceggerathiopsis are far more
plentiful than fronds of Glossopteris, probably due to the fact that
the dry land to the south and west was clothed with Dadoxylon
trees from which the leaves were shed. Throughout this coal-field
the coal is apparently not of such good quality as that from other
parts of the State, owing to the relatively higher percentage of ash
contained. Kerosene shale of very good quality has been mined
near Mittagong.
The Southern (Illawarra) Coal-field. — The upper coal-measures
in the Newcastle district dip south, and at Sydney are nearly
3,000 feet below sea-level. From here they begin to rise, until
at Clifton they again appear above sea-level. Followed still
further southwards, the strata continue to rise until, at Carnbe-
warra on the southern edge of the basin, they reach an altitude
of 1,600 feet. Here they have a thickness of only 40 feet,
whereas, at Jamberoo, some 20 miles northwards, the thickness
has increased to 850 feet, which is about the average thickness
for the district. The strata, often referred to as the Bulli
Coal Measures, consists mainly of shale and sandstones ; but at
Jamberoo the basal beds are tuffs, and two basaltic lava-flows
occur in the series. Cherty tuffs, similar to those of the Newcastle
district, also occur. Five seams of coal exist throughout the
greater part of the district, as follows : —
No. 1, or the Bulli seam 2-1 4 feet in thickness.
No. 2, or the dirty seam . .. . 4-13 ,, .,
No. 3, or the thick seam £-17 ,, ,,
No. 4 seam 7-9 ,, ,,
No. 5, or the bottom seam .. 4-14 ,, ,,
Of these the top, or Bulli seam, has been mined all along its
outcrop from Clifton to Mount Kembla. The coal is an excellent
steaming and coking coal.
The same seam is being mined at Helensburgh in the Metro-
politan Colliery, at a depth of 1,100 feet below the surface, and
in the Sydney Harbour Colliery, at a depth of about 2,900 feet
below sea-level. The coal from the latter colliery is semi-
anthracitic in composition, and is almost smokeless.
CHAPTER X.
PERMO-CARBONIFEROUS PERIOD (continued}.
I. — PERMO-CARBONIFEROUS LIFE,
(a) The Marine Fauna.— -The marine life of this period is
thoroughly Palaeozoic in character, and contains an admixture of
SS*?-^
1
w$nr
mm i
^ri-,ll'l
Fig. 43.
Permo Carboniferous Corals and Bryozoa.
1. Polypora. 2. Stenopora crinita. 3. Trachypora Wilkinsoni. 4. Zaphrentis.
Cainodon. 5-7. Zaphrentis Gregoriana.
86
what would, iri the Northern Hemisphere, be considered as
distinct Carboniferous and Permian types. That it differs
markedly from the marine fauna of the true Carboniferous forma-
tion of New South Wales, already described, is shown by the
following list of its more important members ; such genera as are
common to the two periods are represented, in most cases, by
different species : —
Foraminifera : — Nubecularia, Lituoln, Nodosaria, Endothyra,
Lagena.
Spongida : — Hyalostelia.
Actinozoa :—Zaphrentis, Trachypora.
Crinoidea : — Phialocrinus, Tribrachiocrinus.
Asteroidea : — Pahester.
Echinoidea : — Archceocidaris.
Bryozoa : — Fenestella, Polypora, Protoretepora, Stenopora.
Brachiopoda : — Lingula, Dielasma, Productus, Martiniopsis,
Spirifer, Spirifer ina, Strophalosia.
Pelecypoda : — Aviculopecten, Deltopecten, Mceonia, Meris-
mopteria, Chcenomya, Cleobis, Notomya, Edmondia,
Eurydesma, Stutchburia, Pleurophorus, Astartila, Apha-
naia.
Pteropoda : — Hyolithes, Conularia.
Cephalopoda : — Orthoceras, Goniatites.
Crustacea (Ostracoda) : — Entomis, Polycope, Carbonicola.
PROTOZOA. — Foraminifera are abundant, particularly so in the
lower marine strata of the Pokolbin district. Radiolaria are
not known to occur.
SPONGIDA. — Sponges are uncommon.
CCELENTERATA. — The corals are the only group represented,
and are uncommon, only two genera being known. The refrigera-
tion of the climate, as indicated by the glacial beds, is the cause
generally assigned for the practical extinction of the more
abundant corals of the previous periods.
ECHINODERMATA. — The crinoids were at times abundant,
particularly in the latter part of the Upper Marine Epoch. The
genus Phialocrinus had a calyx up to 4 inches in diameter, and
is the largest known crinoid yet found in Australia. Tribra-
chiocrinus is an interesting type, possessing three simple arms and
87
two double arms — it is the commonest genus, and is confined to
Australia. Large starfish occur, particularly on the Ravensfield
sandstone horizon. Hea-urchins were
cystoicls and blastoids are unknown.
not numerous, while
Fig. 44.
Permo-Carboniferous Echinodermata.
1. Phialocrinus princeps. 2. Palcester giganteus
MOLLUSCOIDEA. — The Bryozoa become more important than
they had ever been before. The Fenestellidre ( Fenestella, Polypora,
&c.) occurred in great numbers, and their beautiful lace-like
structures are wonderfully well preserved in some of the marine
shales. The coral-like genus Stenopora was also abundant, and is
represented by both massive (S. crinita) and branching forms
(S. Tasmaniensis).
The BRACHIOPODA lived in countless numbers, and probably
dominated all the other invertebrates. The Spiriferidse (Spirifer,
Martiniopsis, &c.) and the Productida? (Productus and Stropha-
losia) were the most abundant of these ; the genus Spirifer,
in particular, was represented by large numbers, both of
species and individuals. Martiniopsis supplied the largest
brachiopod shells yet found in Australia. The Strophomenidse
and Orthidse, so abundant in the Carboniferous strata, are
absent here.
Fig. 45.
Permo-Carboniferous Brachiopods.
1. Spirifer convolutus. 2. M artiniopsis subradiatus. 3. Martiniopsis subradiatus
{internal cast). 4-5. Spirifer Tasmaniensis. 6-7. Terebratula (Dielasma) sacculus.
8, 10. Productus brachythcerus (ventral valve). 9. Productus brachythcerus (dorsal
valve).
MOLLUSCA. — These rival the Molluscoidea in numbers, the two
sub-kingdoms together providing the great bulk of the marine
fauna. The Permo-Carboniferous was undoubtedly the *' Age of
the Shell-fish." The Pelecypods dominate the other classes of
the mollusca, and were more abundant and individually larger
than they had been in any previous period. The shells of
Aphanaia attained a length of 15 inches, while Cleobis and
Eurydesma also built very large and thick shells.
89
Fig. 46.
Permo-Carbon if erous Molhi s< -a .
1-2. Eun/desma cordatum (Morris). 3. Aviculopecten tenuicollis (Dana).
4. Mceonia elongata (Dana). 5. Goniatites (Agathiceras) micromphalus (Morris).
6. Keeneia platyschismoides (Eth. fll.). 7. Platyschisma oculum (Sowerby).
8. Orthoceras (Cameroceras) Phillipsi (De Kon.).
The Gasteropoda, while not so numerous as the Pelecypoda,
were larger than they had ever been before. Platyschisma, and
its ally Keeneia, were the largest and most characteristic genera.
The Cephalopoda were relatively uncommon ; Orthoceras still
persists and, together with Goniatites, is fairly abundant on the
Ravensfield sandstone horizon. The great advance in the
Cephalopods, which took place in other parts of the world
90
towards the close of the Palaeozoic Era, and which foreshadowed
their extraordinary development in the Mesozoic Era, has no
parallel in New South Wales.
ARTHROPODA. — Trilobites are unknown, and evidently became
extinct at the close of the Carboniferous Period.
The Ostracods are the only known representative of the sub-
kingdom, and even those are not abundant.
(B.) The Terrestrial Flora and Fauna. — This includes the
following genera : —
Equisitales — - Phyllotheca, Schizoneura, Annularia.
Filicales (Ferns) — Glossopteris , Gangamopteris, Vertebrariu,
Sphenopteris, Alethopteris, Taencopteris.
Cordaitese (?) — Dadoxylon, Noeggerathiopsis.
Coniferse (?) — Brachyphyllum.
Ginkgoacese — Baiera.
Insecta — Neuroptera (?).
Amphibia — Bothriceps.
Pisces (Fish) — Urosthenes.
Fig. 47
Permo-Uarboniferous Plants.
1-2. Glossopteris linearis (McCoy). 3-4. Glossopteris Browniana (Bgt.).
91
The most characteristic member of this flora is the fern
Glossoptens (Fig. 47) ; its fronds occur in enormous numbers, and
the peculiar anastoraising venation shown in the illustration is
very characteristic. Ganyamopteris, although less abundant, is
just as characteristic, particularly for the earlier part of the
period ; it has a similar venation to Glossopteris, but no midrib
Fig. 48.
Permo-Carboniferous Plants.
1. Gangamopteris Clarkei (Feist.). 2. ScMzoneura Australis (Eth. fil.)..
3. BracfiypJiyllum Australe (Feist.). 4. Vertebraria Australis (McCoy). 5. Phyllotheca
Australis — stem (Bgt.). 6. Phyllotheca Australis— whorl of leaves.
(Fig. 48). Vertebraria was the rhizome of Glossopteris. Both
ferns must have nourished abundantly in the coal-measure
swamps, as also did the horsetail Phyllotheca. Dadoxylon was
the largest of the plants, and probably ranged up to 1 00 feet in
height; numerous trunks occur in situ immediately on top of
some of the coal-seams, and it is frequently found as driftwood,
both in the marine and fresh-water beds. It apparently flourished
on the dry land surrounding the coal swamps, and spread over
92
the surface of the coal seams after coal-making conditions had
ceased. The fossil leaves called Nceggerathiopsis are believed to
have been the foliage of these trees. The classification of
Dadoxylon is uncertain, but it is believed to have belonged to the
Cordaitew, a group which combined some of the features of
Conifers and Cycads, and was, perhaps, the ancestors of both.
Schizoneura, Alethopteris, and Baiera appear only towards the
close of the period ; in the Balmain Colliery they occur
immediately above the coal seam, and are associated there
with GLossopteris ; all three plants, as well as Phyllotheca ,
pass up into the overlying Triassic strata. Sphenopteris also
occurs in both formations, but is represented by different
species.
It will be of interest to make a comparison here of the Carbon-
iferous, Permo-Carboniferous, and Triassic floras.
The following table gives a list of the more important members
of the flora from each of these periods : —
Carboniferous.
Permo-Carboniferous.
Triassic.
Equisetales
Calamites
Phyllotheca
Phyllotheca
Schizoneura Aus-
S. Australis
tralis
A nnularia
Equisetum
Lycopodiales
Lepif/odendron
(Unknown)
(Unknown)
Filicales
Aneimitex
Glossopteris
Thinnjeldia
Rhacopteris
Gangamopteris
Tceniopteris
Gardiopteris
Vertebraria
M acrotcmiopteris
A rchcKOpteris
Alethopteris c.f.
Alethopteris Aus-
Australis
tralis
Cordaitese
(?)
Sphenopteris
Dadoxylon
Sphenopteris
(Unknown)
Coniferse
Cycadales
(Unknown)
(Unknown)
Brae hyphyllum
(Unknown)
(?)
Podozamites
Pterophyllum
Ginkgoacese
(Unknown)
Baierti
Baiera
Ginkgo
It will be seen that not a single member of the Carboniferous
flora passed upwards into the Permo-Carboniferous. The re-
frigeration of the climate, which took place at the beginning of
the latter period, as indicated by the glacial beds in New South
Wales and other parts of Australia, has been suggested as the
cause of this marked break between the two floras. There is
also a very marked difference between the Permo-Carboniferous
and Triassic floras, all the more important members of the
former failing to pass the boundary. Some few members
93
of the Triassic flora (Schizoneura, Alethopteris, and Baler a)
.appeared, however, before the close of the Permo-Carboniferous,
and we have, thus, a
.slight commingling of the
two floras in the topmost
beds of the Upper Coal
Measures.
The Permo-Carboniferous
flora, although so different
from that of the Triassic
Period, has, as a whole, a
decidedly Mesozoic aspect,
and were it not for the fact
that some of the fresh-water
beds containing these fos-
sil plants are actually in-
terstratified with marine
strata, containing an un-
doubted Upper Palaeozoic
fauna, the strata contain-
ing the Glossopteris flora
would probably have been
referred to the Mesozoic
Era.
Land Animals. — The Ter-
restrial fauna is a very
limited one ; a Labyrintho-
dont (Bothricepft major] has
been obtained from the
Upper Coal Measures at
Airley in the Lithgow dis-
trict, and is the oldest
veitebrate animal, oth^r
than fish, yet found in
New South Wales. A fos-
sil fa'sh (Urostkenes Aus-
tralia) has been obtained
from the Upper Coal
Measures, both in the
Lithgow and Newcastle
districts, while from the
latter locality, the wings of
some undescribed insects,
belonging probably to the
Neuroptera, have been ob- Fig' 49'
, . ,* Permo-Carboniferous Amphibian Bothrtceps majo
tamed. (A.S.W.)- from Airley.
94
II. ECONOMIC IMPORTANCE OF THE PERMO-CARBONIFEROUS
FORMATION.
The Coal — Quality and Available Supply. — Various estimates
have been made from time to time as to the quantity of coal
available in the Permo-Carboniferous Coal Measures of New South
Wales. The first of these was made by the late Government
Geologist (Mr. C. S. Wilkinson), who, assuming 4,000 feet as the
limit of depth at which economical mining could be carried out,
and allowing one- fifth for loss in working, estimated an available
supply of 78,198,000,000 tons of coal. He excluded seams less
than 2J feet in thickness. In 1890, Professor T. W. E. David,
taking the same limit of depth, but excluding seams under 3 feet
in thickness, arrived at an estimate of from 130,000,000,000 to
150,000,000,000 tons. Still later in 1901, Mr. E. R Pittman,
Government Geologist, with more accurate data as to the area,
over which the coal measures occur, viz , an area of 16,550 square
miles, and assuming an average thickness over this area of 10 feet
of workable coal, reduced the above estimate to 115,346,880,000
tons. The estimate of the thickness of coal used in making this
calculation is a very conservative one. The output for the past
six years has been as follows : —
1905 ... 6,632,138 tons. 1908 ... 9,147,025 tons.
1906 ... 7,626,362 „ 1909 ... 7,019,879 „
1907 ... 8,657,924 „ 1910 ... 8,173,508 „
At this rate of production the estimated available supply would
last for over 12,000 years. The following table gives 'analyses of
the coal from various localities, the figures given in most cases
being an average of a considerable number of published analyses : —
Volatile
Calori-
Locality.
Water.
Hydro-
Carbon.
Carbon,
Ash.
metric
value.
Lower Coal f
Measures.
Hunter River District
Ashford (near Inverell)
Clyde River
1-74
0-71
0-68
39-42
22-90
34-96
51-68
68-96
52-92
7-14
7-43
11-53
13-6
13-83
Middle Coal 1
Measures, j
East Maitland District
1-60
38-85
53-85
870
12-4
(
Newcastle District . . .
1-95
34-48
5420
9-33
12-8
Singleton ,,
1-72
36-76
52-87
8-25
12-7
Upper Coal J
Curlewis
Gunned ah
•2-40
2 '55
*3'30
35-35
56-30
55'35
8-00
6'75
12-0
12*3
Measures.
Lithjjow District . . .
1-87
3] -49
52-61
14-03
11 5
Illawarra ,, ....
0-97
23-10
65-26
1067
12-6
V
Sydney
0-66
17-57
71-09
10-68
13-0
It will be seen that the coals are all anhydrous bituminous
coals, and show a considerable variation in the relative propor-
tions of fixed carbon and the volatile hydrocarbons. These
95
varieties include excellent steam, gas-making, coking, and house-
hold coals ; it is apparent, therefore, that New South Wales
possesses excellent coal resources, both from the point of view of
quantity and quality, and as they are at the same time very
favourably situated for commercial purposes, they form a great
national asset.
Kerosene Shale. — This substance occurs more extensively in
New South Wales than perhaps in any other part of the world.
It is found both in the Upper and Lower Coal Measures, but the
more extensive deposits occur in the former formation. In nearly
all cases the deposits occur at or near the edges of the coal basin ;
it would seem, therefore, that the edges of the coal measure
swamps provided the necessary conditions for the deposition of
this material.
The most extensive deposit at present known is that now being-
opened up at Wolgan, some miles to the north of Lithgow. The
main tunnel here has exposed a seam with an average thickness
of over 4 feet for a horizontal distance of over 4,000 feet, two-
thirds of this thickness being of first grade quality ; ordinary coal
also occurs in this seam, both above and below the kerosene shale.
Kerosene shale also occurs at many other places in the Western
district, including Katoomba, Hartley Yale, and Capertee Valley,
at some of which it has been extensively mined. Important
deposits have also been worked at Joadja, near Mittagong, in the
south-western coal-field, arid at Mount* Kembla, in the Illawarra
district, and an extensive deposit is now being opened up at
Murrurundi.
The New South Wales production of kerosene shale to the end
of 1910 was 1,490,312 tons, valued at £2,250,000.
Kerosene shale is a close-grained, brownish-black rock, with a
peculiar toughness, and a well-marked conchoidal fracture. In
composition it differs markedly from coal, in containing a very
high percentage of volatile hydrocarbons and a correspondingly
low percentage of fixed carbon, as will be seen from the following
analyses of samples of high-grade material from various localities
in New South Wales.
Water.
Volatile
Hydro-
Carbons.
Fixed
Carbon .
Ash.
Torbane .
0'72
69 '69
9-04
20'54
Joadja
0-16
89'59
5-27
4-98
Capertee Valley
0-30
64-40
13-85
21-45
Wolgan
0'30
67'92
11-98
19-80
Hartley Vale
82-24
4-97
12-79
Mount Victoria . .
0'47
67*45
14-63
17-45
Katoomba
0-30
74-10
13-08
15-52
96
The average of the analyses from 61 New South Wales samples
from various localities gives 69*85 per cent, of volatile hydro-
carbon and 14*10 per cent, of fixed carbon, or a ratio of about
5 to 1. With an increasing proportion of fixed carbon, kerosene
shales merge gradually into cannel coals ; inferior grades contain
increasingly higher percentages of inorganic material (ash).
The mode of occurrence is similar to that of ordinary coal, the
two often occurring in one and the same seam, it being not un-
common for the kerosene shale to have a layer of coal both above
and below it. The area over which it occurs is seldom extensive,
as it sooner or later merges into, and gives place to, ordinary coal.
The microscopic structure and composition of kerosene shale
indicate that it has resulted from the accumulation of an ulmic
precipitate, together with seed-spores, pollen grains, and other
vegetable debris. The plant-remains include fronds of the genus
Glossopteris, sometimes in considerable abundance.
It eeems probable, therefore, that near the borders of the
coal-measure swamps, expanses of open water occurred, com-
paratively free from the usual coal-making vegetation. Upon the
surface of this water showers of spores and pollen grains fell from
the surrounding vegetation, while the water itself was more or less
charged with organic material in solution. These materials
slowly accumulated at the bottom of the swamp, and as they had
a different chemical composition from that of ordinary plant fibre,
the resulting rock (kerosene shale) has a correspondingly different
composition from that of ordinary coal.
Clays. — The shales of the coal-measures include some beds of
shale which are very suitable for making bricks, pottery, &a
These are being utilised to a considerable extent in the Lithgow
district.
III. THE PERMO-CARBONIFEROUS GLACIATION.
Nature and Extent of the Glaciation. — The occurrence of
glaciated pebbles and erratics in both the Lower and Upper
Marine Strata has already been referred to. This glacial horizon
is not confined to New South Wales, but occurs also in Victoria,
Tasmania, South Australia, and Western Australia, and is one
of the most interesting features of the Per mo-Carboniferous
Period in the Southern Hemisphere.
As already pointed out the glacial beds of the Hunter River
district in New South Wales are not typical boulder clays or
till, but are marine sediments into which glaciated pebbles and
large erratics were dropped by floating ice as the sediments.
97
accumulated. No actual glaciers are known to have existed in
New South Wales, but the nature of some of the transported
boulders, Devonian quartzite and Silurian limestone, suggests,
that they may have been derived from corresponding formations
in this State. In Victoria, Tasmania, and South Australia,
however, the glacial deposits are true moraine deposits, which
rest upon glaciated land surfaces. At Bacchus Marsh, in Vic-
toria, fresh-water sandstones, containing Gangamopteris and
Schizoneura, are interstratified with the glacial deposits. In the
Inman Valley in South Australia, the removal of the glacial
deposits is re-exposing the Permo-Carboniferous valley down
which the one-time glacier flowed. Tn West Australia the glacial
beds are analogous to those of New South Wales. There can be
no question, therefore, that gla.ciers existed on the Australian
Continent during at least part of the Permo-Carboniferous
Period ; that these glaciers extended at times down to sea-level is
shown by the fact that glaciated pebbles and erratics were tran-
sported by floating ice and distributed over the bottom of the
shallow Permo-Carboniferous sea.
This Permo-Carboniferous glaciation was not limited, however,
to Australia ; in Peninsular India (Gondwana Series), in South
Africa (Dwyka Series), and in Brazil, glacial deposits analogous
to those of Australia are found, in each case associated with
strata containing the characteristic Glossopteris flora. The
boulder beds of all these regions, and the glaciated land
surfaces upon which they rest, are just such evidences as
those upon which the existence of the Pleistocene Ice Age
of the Northern Hemisphere depends, and the reality of
which is universally accepted. The conclusion has been gene-
rally arrived at, therefore, that a glacial period existed in
the Southern Hemisphere during the Permo-Carboniferous
Period.
The complete change in the flora which ushers in the Permo-
Carboniferous Period in Australia is quite in harmony with this
view. The marine fauna, however, does not lend the same
support. The absence of reef-building corals is, of course, signi-
ficant ; but there is not that marked difference in the marine
faunas of the Carboniferous and Permo-Carboniferous Periods
which might have been expected had there been a refrigeration of
the climate, such, for example, as that which produced the Great
Ice Age of the Pleistocene Period. On the contrary the glacial
boulder beds of the Irwin and Gascoyne River Districts of West
Australia occur in a marine series of strata which contains a
remarkable commingling of the Carboniferous and Permo-
Carboniferous marine faunas of New South Wales ; a similar
commingling of these two faunas appears to exist to some extent
3910— D
98
in Queensland also. This shows that the change from one fauna
to the other was a gradual one, and not a sudden one as might be
expected if it were due to a sudden change to a colder climate. In
the Northern Hemisphere, on the other hand, the palseoritological
evidence of the Pleistocene Period strongly supports the theory
of an Ice Age. While it must be admitted that extensive
glaciers existed in Australia during the Permo-Carboniferous
Period, and that many of these glaciers extended down to
sea-level, it is improbable that Australia, during any part
of this period, was buried under an ice-sheet or succession
of ice-sheets analogous to those which submerged such a large
portion of the Northern Hemisphere during the Pleistocene
Ice Age.
The transportation of glacial material by floating ice extended
to as far north as the Bo wen River in Queensland, and
the Gascoyne River in West Australia, but the existence of
land ice is not known for certain from further north
than Derrinal in Victoria and the Inman Valley in South
Australia. The direction of the striae on the glaciated land
surfaces indicates a general northerly direction of movement for
these glaciers.
Cause of the Glaciation. — The cause of this glacial period, and
particularly its peculiar localisation, is one of the outstanding-
problems of geology. The conditions which produced the Pleis-
tocene glaciation were world-wide in their effect, and the areas
most strongly affected were more or less circumpolar. In the
Permo-Carboniferous Period, on the other hand, the regions
affected were for the most part in the Southern Hemisphere, and in
India glaciers, extending nearly to sea-level, existed within a few
degrees of the equator. The distribution of land and sea at this
time was possibly an important factor. The remarkable simi-
larity of the floras of Australia, India, and South Africa at this
time leads to the inference that these regions, now so widely
separated, were joined by direct land connections, and formed
parts of a continent, covering part of what is now the Indian
Ocean ; this supposed continent has been named Gondwana Land.
There are also reasons for thinking that Australia at this time
had direct land connection with Antarctica and thence to South
America. With this distribution of land and sea, there must
have been a very different oceanic circulation to that which exists
at the present day, a condition of things which must have had
some corresponding influence on the climate. This factor, in
itself, was probably not the main one in producing the glacial
conditions, but was most likely a strong contributing cause
working in conjunction with other factors which are still
unknown.
99
SUMMARY OF THE PERMO-CARBONIFEROUS PERIOD.
No very definite information is yet available as to the earth
movements which took place at the close of the Carboniferous
Period in New South Wales. The unconformity, if any, which
exists between the strata of this and the next period, is not
very marked where junctions between these two formations
are definitely known to occur. If any uplift did take place at
the close of the Carboniferous it was quickly followed by a sub-
sidence which allowed an extensive transgression of the sea
to take place. The limits of this sea are not definitely known,
but it certainly covered a considerable portion of what is now
the Hunter River district, as well as large areas between there
and the Queensland border. One of these areas extended from
the coast at the mouth of the Macleay River westwards to
the main tablel ind ; a second area occurred in the Drake
district near the Queensland border, and extended westwards
to at least as far as Emmaville. What the limits of these
transgressions of the sea were, and as to whether they were
separate inlets or portion of one continuous sea, is not yet
known. These marine conditions at the beginning of the
Permo-Carboniferous Period were preceded in some localities for
a limited time by fresh-water conditions, during which some
fresh- water beds, including a coal seam in one case, were deposited ;
the places where this occurred seem to have been limited in area.
In this epicontinental sea was deposited that thick series of
marine sediments known as the Lower Marine Series, all of
which must have been laid down in comparatively shallow water,
floating ice, derived perhaps from glaciers in Victoria and
Tasmania, drifted northwards on the surface of this sea, dropping,
as it melted, its load of morainic material into the marine
sediments as they were being deposited. The water of this sea
was inhabited by an exceedingly numerous and varied marine
invertebrate fauna whose hard parts have been beautifully
preserved in many of the strata. At certain localities these
remains collected in such abundance as to form beds of limestone.
From time to time this tranquil deposition of sediments was
interrupted by volcanic eruptions on a considerable scale, as a
result of which extensive lava flows were poured on to the
surrounding sea bottom, while immense quantities of volcanic ash
were distributed far and wide. The volcanic cones from which
these eruptions took place probably stood as islands in this
shallow sea. To allow of the deposition of such a great thickness
of shallow-water marine sediments (4,600 feet) as was deposited
during the Lower Marine Epoch, a more or less continuous
subsidence must have been slowly taking place.
100
An upward movement of the Earth's crust now followed, which
brought about the entire withdrawal of the sea, converting some
of the areas previously covered by it into dry land, but converting
the southern area (Hunter River district) into a large fresh-water
lake, which extended in a north-westerly direction at least as far
as Muswellbrook, but how far south and south-west is not at
present known. A smaller lake extended from Inverell to the
Queensland border. In these lakes the shales, conglomerates, and
coal seams which constitute the Lower Coal Measures were
deposited. Twice during this epoch the water shallowed
sufficiently to allow of the whole area becoming covered by
dense vegetation, whose accumulated remains formed two seams
of coal with an aggregate thickness of about 40 feet. This
thickness of coal would have required a thickness of at least
280 feet of vegetable material for its formation, the growth and
accumulation of which must have required a very long period of
time.
Renewed subsidence now again allowed the sea to invade the
land. This second transgression did not reach its maximum
extent until fairly late in the Upper Marine Epoch, when the
sea extended over the area approximately shown on the map.
(Fig. 29.) The area then covered did not coincide with that
covered by the Lower Marine transgression, for while it extends
considerably farther to the west and south, its northern extent
was limited to the present Hunter River district. The Devonian
and Silurian strata covered by the Upper Marine deposits in the
southern and western parts of the area effected had been
undergoing denudation during the Carboniferous Period and the
earlier part of the Perino-Carboniferous Period ; this resulted
in the development of an extensive peneplain in these rocks,
and exposed the granite bosses by which they had been intruded
at the close of the Devonian Period. (See Fig. 52.) As the sea
now slowly advanced on the land, the waves worked over the
regolith on this old land surface and produced the thick basal
conglomerates which mark the base of the Upper Marine Series
in these regions
This re-advance of the sea was accompanied by a similar
marine fauna to that which had inhabited it during the Lower
Marine Epoch ; very few of the species of the older fauna failed
to reappear, and but few new species had developed in the
meantime. That glacier* still existed (or had reappeared) is
evidenced by the erratics which occur in the Upper Marine
sediments. Vulcanism still continued, but the centre of activity
had shifted to what is now the Illawarra district. From one
point of eruption near Kiama a great series of basic lavas and
tuffs were poured out ; at first great showers of volcanic ash,
101
large blocks and bombs rained down into the sea, causing a
wholesale destruction of the animals by which it was inhabited,
then followed great floods of molten lava which spread far and
wide over the sea bottom. After these eruptions had been in
progress for some tim^, a second centre of activity developed some
few miles to the south at Cambewarra, from which trachytic
lavas and tuffs were ejected. The volcanic activity in these
regions continued until the close of the epoch.
The development of a land barrier to the east now cut off the
Upper Marine Sea from the ocean and converted it into a fresh-
water lake in which the Upper Coal Measures were deposited. The
great thickness of these beds, and the fact that throughout they
evidence shallow-water conditions of deposition, show that a slow
subsidence was in progress. Each coal-seam indicates a period
of comparative rest from the downward movement, during which
the waters silted up and became sufficiently shallow to allow of a
dense growth of swamp vegetation extending far and wide over
its surface. Sooner or later renewed subsidence carried the
accumulation of vegetable material beneath the water, and
brought about the deposition on top of it of beds of shale, sand-
stone, and conglomerate. Volcanic eruptions still continued ; in
the Newcastle district, showers of the finest volcanic dust from
time to time rained down into the coal-swamps, while in the
Murrurundi and Kiama districts basic lava-flows were poured
out at intervals over the lake-bottom.
It will be seen from what has already been stated that a sub-
sidence area developed in the eastern part of New South Wales
at the beginning of and continued more or less throughout the
Permo-Carboniferous Period. That the area affected and the
extent of subsidence varied in different parts of the regions
named is shown by the following table giving the formations
deposited in the respective areas, together with their thicknesses : —
Hunter
River
District.
Illawarra
District.
Lithgow
District.
Drake District.
Macleay River
area.
ft.
ft.
ft.
Upper Coal Measure
1,500
850
480
Absent.
Dempsey Series
2.000-3,000 ! Absent.
Absent.
do
Middle Coal Measure 800-1,700
do do
do
Upper Marine Series ! 6,400
3,200 400
do
Lower Coal Measure
300
150 Absent.
do
Lower Marine Series
4,800
Absent.
do Present
(thickness
unknown).
Total Thickness
17,700
4,200
880 Unknown.
102
The apparently permanent retreat of the sea at the close
of the Lower Marine Epoch from the areas covered by it in
the Emrnaville, Drake and Macleay River districts suggests
that "some important earth movements may have affected these
regions at that time. This is supported by the fact that the
Lower Marine strata here are much more highly folded than
those of the Hunter River district, and that they have been
extensively intruded by plutonic igneous rocks. The overlap of
the Upper Marine strata on the Lower Coal Measures and
Lower Marine Series at several places in the northern edge of
the Maitland coal-field lends further support to this view. Jt
would appear probable, therefore, that at the close of the Lower
Marine Epoch (or perhaps Lower Coal Measure Epoch) the
north-eastern part of the State was subjected to erogenic earth-
movement which folded the Lower Marine strata and lifted
them above sea-level. The folding was accompanied by the
intrusion of plutonic igneous rocks. The strength of this
movement decreased southwards, and died out as the present
Maitland district was approached, the only effect here being to
cause a slight overlap of the Upper Marine Series on the earlier
Per mo-Carboniferous strata. Renewed orogenic earth-movements
took place in the same region at the close of the Permo-
Carboniferous Period, and this time extended sufficiently far
southward to develop a series of broad anticlinal and synclinal
folds in the Permo-Carboniferous strata along the northern edge
of the Maitland coal-field. Only one of these folds (the Lochinvar
Anticline) extends much to the south of the present course of the
Hunter River, and even this soon flattens out and disappears.
This was the last occasion upon which orogenic earth -movements
are known to have affected any part of New South Wales.
CHAPTER XI.
TRIASSIC AND JURASSIC PERIODS.
ABOVE the Permo-Carboniferous formation described in the last
chapter, there is found in New South Wales an extensive series of
Fig. 50.
Narrabeen Beds (Shales, Sandstones, and Conglomerates), as seen in the Cliff Sections
on the coast near Newport.
104
fresh- water beds, which rest conformably, for the most part, upon
them, but which contain a distinctly different fossil flora ; this
flora is of undoubted Mesozoic age. These fresh- water beds are
overlain in turn, in the north-western part of the State, by marine
strata of Cretaceous age. As they represent the total sedimenta-
tion which took place from the close of the Palaeozoic Era until the
beginning of the Cretaceous Period, they are generally, in Eastern
Australia, referred to as the Trias- Jura formation. It is con-
sidered by some authorities that part of these fresh-water beds
in New South Wales (the Hawkesbury Series) are of Triassic
age, while the remainder (Clarence Series and Artesian Series)
are considered to have been deposited later ; these they consider
to be of the same age as the so-called Trias-Jura beds of the neigh-
bouring States of Queensland and Victoria. The reasons for this
will be discussed later.
The Triassic and Trias-Jura formations in New South Wales
occur in several distinct areas, and have been named as follows : —
1. The Hawkesbury Series Triassic.
2. The Clarence Series ) m • T
3. The Artesian „ } Tnas-Jura.
4. The Talbragar „ Jurassic.
It will be convenient to describe each series separately, and
discuss their relative ages subsequently.
1. THE HAWKESBURY SERIES.
These overlie, to a considerable extent, the strata of the main
Permo-Carboniferous coal-basin of New South Wales. They out-
crop along the coast from the Shoalhaven River nearly to
Newcastle, and extend westwards to Lithgow. What are said
to be outliers of this series occur as far north as Camden Haven
and Broken Bargo. Adjacent to Sydney, the base of the series is
nearly 3,000 feet below sea-level ; southwards, westwards and
northwards the strata rise gradually until in the Illawarra
Range they reach an altitude of nearly 1,000 feet and at Lithgow
over 3,000 feet above sea-level. They cap the greater part of the
Blue Mountain Tableland.
This series has been subdivided as follows :—
1. The Wianamatta Stage.
2. The Hawkesbury „
3. The Narrabeen ,,
The Narrabeen Stage. — The beds belonging to this stage
consist of sandstones and shales, with occasional thin beds of
conglomerate. They attain their maximum thickness near
105
106
Sydney, where, in the Cremorne bore, the following section was
proved : —
Hawkesbury Sandstones ... ... ... 1,020 feet.
Narrabeen Beds —
Chocolate shales ... ... ... ... 170 ,,
Sandstones, shales and conglomerates ... 1,082 „
Cupriferous shales ... ... ... 38 ,,
Estheria shales ... ... ... ... 561 „
Upper Coal Measures ... (Thickness unknown.)
The Estheria shales are so called because some of the beds con-
tain immense numbers of a small ostracod of that name ; beds of
sandstone and conglomerate are interstratified with these shales.
The cupriferous shales which follow are probably redistributed
tuffs, and contain a small percentage "of copper, too small, how-
ever, to give the beds any commercial value. Following these
there is a thick series of conglomerates, sandstones and shales, the
latter containing abundant fossil plants. The chocolate shales,
which occur at the top of this stage, are also redistributed tuffs,
and have a characteristic chocolate-red colour, which, together
with their peculiar lithological characters, enables them to be
readily identified. As this bed maintains these characters over
the whole of the area in which the Hawkesbury Series occur, it is a
useful " persistent horizon" in mapping these beds. These
chocolate shales outcrop strongly on the coast at Narrabeen, a
few miles north of Sydney, from whence the formation gets its
name.
When followed westwards, the Narrabeen beds are found to
thin considerably, as will be seen from the following sections
taken from various localities at increasing distances westwards
from Sydney : —
Cre-
morne
Bore,
Sydney.
More-
bank
Bore.
Euroka
Bore.
Wood-
ford
Bore.
Clar-
ence
Bore.
Lith-
gow.
Hawkesbury Sandstone
Stage
ft.
1 100
ft.
1 000
ft.
079
ft.
284-
ft.
1Q1
ft.
135
Narrabeen Stage-
Chocolate shales
Shales and sandstones..
Copper shales
Estheria beds .
170
1,082
38
561
}W
} 749
V 1,165
921
355
241
'
Totals (Narrabeen Stage)
1,851
1,493
1,165
921
355
241
107
fffli
In the western part of the Blue Mountains the Narrabeen beds
consist mainly of massive sandstones, and the chocolate shale bed
(170 feet thick at Sydney) has split into three well-defined bands
separated by sandstone, the upper and lower bands being 130 feet
apart. These are well shown in the
road-cuttings on the Mount Victoria ^rxrso
Pass. On the north-western edge of
the basin, at Gunnedah and Mur-
rurundi, beds of conglomerate, about
200 feet in thickness, occur at the base
of the Narrabeen beds. In the south-
western part of the basin the Narra-
been beds are missing, having been
overlapped by the Hawkesbury sand-
stones.
Fossil plants are abundant in some \ -g |;
of the shales, particularly those near / J3 S-i
the top of the series, as, for example, \ +* 2 li
in the cliff sections along the coast
between Narrabeen and Barranjoey.
Ripple-marks, annelid tracks and bur-
rows, and sun-cracks are common in
many of the shale beds, while current-
bedding is frequently seen in the sand-
stones. All these features, together
with the occasional occurrence of
bands of conglomerate, furnish con-
clusive evidence of shallowness of water
in which these beds were deposited.
The Hawkesbury Sandstone Stage. —
These beds outcrop strongly along the
coast in the neighbourhood of Sydney,
and form the surface rock of the
greater part of the Blue Mountain
tableland. The precipitous wall-like
escarpments which this formation pre-
sents around the sides of the Blue
Mountain valleys is due to the under-
mining of the hard Triassic sandstones
by the more rapid weathering of the underlying
of the coal-measures.
S o
ill
0 %®
02 --3
la
a
•<
soft shales
The Hawkesbury Sandstone formation consists mainly of
massive sandstones and grits, which attain a maximum thickness
of 1,100 feet at Sydney. Occasional thin lenticular beds of
carbonaceous shale occur, but are always limited in extent.
108
Current-bedding is a frequent and conspicuous feature in the
sandstones, the prevailing direction of dip of the laminae being
Fig. 53.
Triassic Sandstones, Valley of the Waters, Blue Mountains.
north-north-east, arid the average angle of dip about 20 degrees,
It seems obvious from this that the sandstones were deposited
in shallow water in which rapidly-moving currents, coming mainly
109
from the south-south-west, were transporting large quantities
of sand. Examples of contemporaneous erosion are also not
uncommon. Some of the lenticular beds of shale above referred
bo, contain fossil-plants, fish, and fresh-water shells (Unio), and
must have been deposited in small lakes or lagoons temporarily cut
off from the main body of water in which the coarser sediments..
no ,;
were being deposited. The sandstones vary somewhat in com-
position— some are very argillaceous, others are the reverse : others
again contain much mica, still other beds are very ferruginous ;
while small flakes of graphite are not infrequently found in many
of the strata. Where the Hawkesbury Sandstones have been
intruded by basalt-dykes, prismatic structure has been developed
in many cases, the most notable being that at Bondi.
Ill
This has been produced in what were porous sandstone beds,
saturated with water at the time the intrusions took place ;
unequal heating started convection currents which heated the
particular sandstone bed for some distance away from the
contact, and caused the rock to expand. Subsequent contraction
on cooling developed the joints whose intersection resulted in the
prismatic structure. This prismatisation is always accompanied
by a variable amount of secondary silification, which has con-
verted the sandstone into an imperfect quartzite. The altered
rock has been much in demand for road-making purposes, and is
known to the road-maker as " white metal"; consequently, these
interesting occurrences have been in nearly every case quarried
out and removed.
Another interesting feature of the Hawkesbury Sandstones is
the contortion of the laminae in certain of the strata showing
current bedding. No really satisfactory explanation of this
feature has yet been forthcoming.
Many excellent beds of " free-stone," ranging up to 60 feet
in thickness, are found, and have been extensively quarried for
the building of the metropolis. Gold occurs more or less
throughout the Hawkesbury Sandstones, but the quantity (2
or 3 grains to the ton) is, of course, too small to be of any
value ; as much as 2 or 3 dwt. per ton has been found in some
places, and has given rise to much profitless expenditure of
money in prospecting the rocks in such localities.
The Wianamatta Stage. — The strata of this stage consist of a
thick series of shales, with occasional bands of sandstone,
carbonate of iron, and thin hands of impure coal. The beds
attain their maximum thickness in the Picton and Campbelltown
districts, wh^re, according to the late Rev. W. B. Clarke, the
thickness approaches 700 feet, and the formation includes grits
and sandstones. The name Wianamatta, which was given to
them by this geologist, is the native name for South Creek ; he
recorded from this locality a seam of impure coal, 4 feet in
thickness. The Wianamatta Shales overlie the Hawkesbury
Sandstones over large areas, but do not extend so far to the west
and north as the latter formation. In the Blue Mountains, they
have been removed from considerable areas by denudation ; the
small outliers occurring under the basalt caps at Mounts Tomah
and King George, and the larger outlier at Springwood,.
testifying to the greater area once occupied by these shales in
this region.
Small lenticular beds of impure fresh-water limestone occur at
Kurrajong, which contain fossil Ostracods antf Foraminifera.
The fossil fauna found in the Wianamatta Shales inclydeB fresh-
water fish, pelecypods, and
large amphibia (Labyriri-
thodonts) ; fossil plants
also occur in considerable
abundance. The shales
provide excellent brick-
making material, and are
extensively quarried for
that purpose m\the en-
virons of Sydney ; it is
from such quarries at St.
Peters that specimens of
the fossil fish and amphibia
have been obtained.
Relation of the Hawkesbury
Series to the Upper Coal
Measures.
Throughout the greater
part of the area over which
the Hawkesbury Series oc-
cur, they rest conformably
upon the Upper Coal
Measures, so that the Tri-
assic sedimentation seems
to have followed that of
the Permo - Carboniferous
without any interruption ;
it is a matter of difficulty
to fix the dividing line
between the two forma-
tions. At ^Ellalong, how-
ever, on the northern edge
of the basin, a well-marked
unconformity occurs, as
may be seen from the
section. (Fig. 56.)
A comparison of the
floras of the two periods
has already been made on
page 92, wherein it was
shown that, although a
marked difference exists,
a slight commingling of
them occurs at the junction
of the two formations.
113
Life of the Triassic Period (Hawkesbury Series).
(A.) Fossil Plants.
Equisetacese — Schizoneura Australe, Phyllotlieca Hooker i (P.
concinna], Equisetum.
Filicales — Thinnfeldia odontopteroides, Thinnfeldia Narra-
beenensis, Sphenopteris, Alethopteris (Cladoplebis) Australia, Mac-
rotcvniopteris Wianamattw, Oleandridium lentriculiforme^ titenop-
teris rigida, Cycadopteris scolopendrina, Taeniopteris.
Cycadales — Podozamites lanceolatus.
Ginkgoales — Ginkgo dilatata, Baiera midtifida.
Comferse—Araucarites.
Fig. 57.
Triassic Plant. Thinnfeldia odontopteroides.
(B.) Fossil Fauna.
Foraminifera — Nubecularia, Haplophraymium, Endothyra,
Discorbina, &c.
Pelecypoda — Unio, Unionella.
114
Crustacea (Ostracoda) — fieyrichia, Darwinula, Cytheridce,
Estheria.
Pisces (fish) — Palaeoniscus, Myriolepis, Cleithrolepis, Pleuracan-
thus, Elonichthys, Gosfordia, Apateolepis, Dictyopyga, Sagenodus,
Acentrophorus, Belonorhyncus, Semionotus, Pristisomus, Elpiso-
pholis, Pholidophorus.
Amphibia (Labyrinthodonta) — Mastodonsaurus, Platyceps.
THE EQUISITALES. — Schizoneura had already appeared before
the close of the Permo - Carboniferous • it continued on into the
Triassic, but soon became extinct. Phyllotheca, on the other
hand, continued to flourish luxuriantly throughout the Triassic.
Equisetum makes its first appearance here.
THE FILICALES. — Thinnfeldia is the largest and most abundant
of these; the size of the frond and the shape of the pinnules varied
considerably, but the frond itself was always dichotomous. Among
the many thousands of these which have been collected, not one
fertile frond has yet been observed, and it is more than probable
that this so-called fern is the vegetation of some more highly
organised plant. Specimens of an influorescence have been found
associated with Thinnfeldia both at Mount Piddington and at
Narrabeen, which possibly may have been derived from the same
plant. Macrotwniopteris and Oleandridium are more charac-
teristic of, and are fairly abundant in, the Hawkesbury Series.
THE FISH. — These occur on three distinct horizons — 1st, the
Hawkesbury Sandstone Stage, at Gosford ; 2nd, the Wianamatta
Stage, at St. Peters (near Sydney), and at Mittagong ; 3rd, the
Talbragar beds on the Talbragar River, near Gulgong ; the latter
beds have been referred to the Jurassic period by some writers.
There is some doubt as to whether the Gosford fish-beds are near
the base of the Hawkesbury Sandstones, or near the top of the
Narrabeen beds. The fossil fish genera described from the locali-
ties are as follows : —
Hawkesburv Stage
(Gosford).
Wianamatta Stage
(St. Peters).
Talbragar Beds
(Jurassic).
Elasmobranchii
(An imperfect speci-
Pleuracanthus.
men).
Dipnoi Gosfordia.
Sagenodus.
Teleostomi Myriolepis.
Myriolepis.
Coccole.pis.
(Actinopterygii)
Semionotus.
Cleithrolepis.
Pholidophorus.
Semionotus.
Cleithrolepis.
Pholidophorus.
Aphnelepis.
Aetheolepis.
Archceomene.
Apateolepis.
Acentrophorus.
Leptolepis.
Dictyopyge. Platysomus.
Belenorhyncus. Elipsopholis.
Pristisomus. Elonichthys.
Peltopleurus. Palceoniscus.
115
The Gosford fish are all
regarded as being hornotaxial
with the Triassic of Europe ;
the assemblage of fish from
the Wianamatta shales at St.
Peters, however, is remarkable,
in that it displays an aston-
ishing commingling of European
Palaeozoic and Mesozoic genera.
Such genera as Pleur acanthus,
Sagenodus, Elonichthys, Platy-
somus, Paloeoniscus, Acentro-
phorus, and Elipsopholis range
in Europe from Lower Car-
boniferous to Permian, and do
not pass upwards beyond the
Palaeozoic. On the oth°r hand,
Semionotus, Cleithrolepis, and
Pholidophorus are typical of
the Mesozoic in Europe. This
seems all the more strange
when one remembers that at
Gosford, which is on a lower
horizon, only Mesozoic types
occur. The Talbragar fish seem
to have their nearest allies in
the Jurassic of Europe. Pleura -
canthus appears to have been
the largest of these Triassic
fish, and attained a length of
nearly 6 feet.
THE AMPHIBIA. — These had
already made their appearance
before the close of the Permo-
Carboniferous, but the Triassic
examples are larger ; one un-
described Mastodonsaurus (a
Labyrinthodont) from the St.
Peters fish beds, has a length
of quite 12 feet.
THE CRUSTACEA. — Esiheria
was the most important genus,
and occurred in enormous num-
bers in the early part of the
period.
116
Fig. 59.
New South Wales Triassic Fish.
Palceoniscus antipodeus. b. Cleithrolepis granulatus.
2. THE CLARENCE SERIES.
These also are fresh-water beds occurring in the form of a basin
in the north-east corner of New South Wales. They outcrop
strongly over the eastern part of the watershed of the Clarence
River and along the coast from Woolgoolga to the mouth of the
Richmond River; northwards they cross into Queensland, and
are continuous with the Ipswich beds of that State. At Grafton,
which is at about the centre of the basin, a borehole, put down in
search of artesian water, passed through a thickness of 3,700 feet
117
of these beds, and was still in them when boring ceased.
Clarence Series have been subdivided as follow :—
The
Upper Clarence Beds
Middle ,,
Lower „
Shales, Ac.
Massive sandstones.
Shales and sandstones with coal
seams, conglomerate.
CO
The conglomerates at the base of the series are very thick, and
outcrop strongly around the western edge of the basin ; they are
auriferous at Pretty Gully, about 15 miles from Drake, but
not payably so. Five seams of coal occur in the Lower Clarence
118
Series above the conglomerates, and range from 2 to 37 feet in
thickness. So far as these seams have been prospected, they
appear to contain too many clay-bands for the coal to have much
economic value, except, perhaps, for local purposes. The sand-
stones of the Middle Clarence Beds have a strong lithological
resemblance to those of the Hawkesbury Series, and on that
account it has been suggested that the Lower, Middle, and
Upper Clarence beds are the equivalents of the Narrabeen,
Hawkesbury Sandstone, and Wianamatta stages of the Hawkes-
bury Series. The fossil flora of this series possesses some
differences from that of the Hawkesbury Series, but is quite
similar to that of the Ipswich beds of Queensland and the
Trias- Jura beds of Victoria ; it is characterised by the relatively
great abundance of Tcuniopteris Daintrei, which has not yet been
found in the Hawkesbury Series. Several species of Thinnfeldia
are present, but the genus is more variable and the fronds more
delicate than those from the Hawkesbury Series. Thinnfeldia of
the true Hawkesbury type, as well as Macrotceniopteris, have,
however, been found near the base of the series; coniferous wood
occurs in abundance.
3. THE ARTESIAN SERIES.
Fresh-water beds of Trias-Jura age outcrop along the western
edge of the New England Tableland, from Dubbo northwards
past Narrabri and Warialda to the Queensland border. Here
they join on to the Ipswich beds, and are thus linked up by way
of Queensland with the Clarence Series. The width of outcrop
of the artesian beds (the intake beds) in an east and west direction
is, on the average, about 60 miles, beyond which they dip west-
wards beneath Cretaceous marine strata. Further to the west
they have been met with at considerable depths in the bore-holes
put down to tap the artesian water which they contain. As they
have been intersected at localities as far apart as Moree, Coon-
amble, and Nyngan, these Trias-Jura strata must underlie the
Cretaceous system over a very large area in north-west New South
Wales, an area estimated by Mr. E. F. Pittman as being about
•83,000 square miles. The correlation of these beds with the
Clarence Series is based, firstly, on the occurrence in both of them
of Tceniopteris Daintrei ; and secondly, on the fact that, as already
stated, they are actually linked up with them by way of the
Ipswich beds, in Queensland. The occurrence of artesian water-
in these strata is of the very highest importance to this part of New
South Wales, which has a low average rainfall, and is subject to
long periods of drought. Many artesian weJls have been sunk
throughout this region, ranging up to nearly 4,000 feet in depth,
from which flows of water have been obtained in the case
of individual bore-holes up to 3,000,000 gallons per day. The
119
water from some of the deeper bores has a fairly high temperature,
115° F. in the case of the Moree bore, and although the bore water
generally contains a fair percentage of mineral matter, it has
proved to be excellent for stock. Its use for agricultural pur-
poses is not altogether so satisfactory, as, after it has been used
for a few years, the soil becomes too highly charged with the
mineral substances brought on to the land by the bore water.
Upwards of 160 wells have been put down to date; but some of
them are at present providing a considerably diminished supply
as compared with that given at first ; whether this is due to
exhaustion in the artesian beds, or due to the partial caving in of
the bore-holes has not yet been determined.
4. THE TALBRAGAR SERIES.
These occur on the Talbragar River, about 20 miles from
Gulgong ; they are fresh- water beds about 40 feet in thickness, and
the area over which they extend is only a few acres in extent.
The lowest beds consist of ferruginous cherty shales, about 10 feet
in thickness, literally crowded with fish and plant remains. The
plants are preserved in the form of siliceous impressions, their
pure white colour being in marked contrast to the yellow colour
of the rock on which they occur ; the fish also occur as impressions
on the shale, in most cases with the bones replaced by ochreous
material, and are beautifully preserved. These fish are crowded
together as if suddenly destroyed, a feature characteristic of the
Gosford fish beds also ; this sudden destruction was probably due
to a rapid influx of sediment into the lake in which the fish were
living. The fish beds are succeeded by white siliceous shales and
siliceous ironstone, both of which are unfossiliferous. The
Talbragar deposit, as a whole, appears to lie in an erosion hollow
in the Hawkesbury sandstones. The fossil flora is very similar to
that of the Clarence Series ; Podozamites lanceolatus is particularly
abundant, while Tceniopteris Daintrei and Thinnfeldia are not
uncommon. The fish are different from those so far obtained
from other Trias-Jura localities in New South Wales, and have
their nearest allies in the Lias and Jurassic of Europe ; they are
listed on page 114.
Correlation of the Hawkesbury, Clarence, Artesian, and Tal-
bragar Fresh-water Beds. — Considerable diversity of opinion exists
as to the relative age of the Triassic and Trias- Jura beds from
the different localities in New South Wales. The Hawkesbury
Series are generally accepted as being of Triassic age ; the flora
and fauna both support this view, and the absence of any break
in the sedimentation in passing from the Permo-Carboniferous
strata to the Narrabeen beds (with the exception at ^Ellalong
already mentioned) confirms it. With regard to the Clarence and
120
Artesian Series, however, the view is held by some geologists
that these were deposited later than the Hawkesbury Series. It
is now the generally accepted view that the Clarence and Artesian
Series are of the same geological age as the Ipswich and Burrum
formations in Queensland, with which they are, in fact, co-extensive,
and of the same age as the Gippsland and Cape Otway beds in
Victoria ; in both of these States the age of these freshwater beds
is taken as being Trias- Jura. Various arguments have been put
forward in support of the view that the Hawkesbury Series are
older than the Clarence, Artesian, and Talbragar Trias-Jura
beds. Taking the Palseontological one first as being the most
important, what differences there are in the fossil floras will be seen
from the following lists : —
Schizonfum AustTdla
Hawkes-
bury
Series.
Clarence
and
Artesian
Series.
Talbragar
Beds.
Ipswich
Beds.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
(or a simi
X
X
X
X
X
X
iar form)
.A.
Phyllotheea Hookeri
Equi^tujn
ThiwnfcldicL odontopt&Toidas
Thinnfeldia N arrabeenensis
Sph €nopt&ris
AlattioptfiTis A.ustvci,l'ifi
Macrotayniopteris Wianamattce. . .
Oleandridium lentriculiforme
Tceniopteris Daintrei
Podozamites lanceolatus
Ginkgo dilatata
BuidTtt wiultijidci
A raucarites
How far the differences are due to insufficient collecting, or how
far they represent real differences in the respective floras, is at
present somewhat difficult to decide. The fossil fish of the
Talbragar beds belong to genera which have not yet been found
in the Hawkesbury Series, and have their nearest allies in the
Jurassic of Europe ; when one remembers, however, that one
particular bed in the Wianamatta shales at St. Peters con tains an
assemblage of fossil fish quite different from that in another bed
in the same quarry, this fact loses some of its weight. The
absence of arte.-ian water in the Hawkesbury Series, which occurs
in the form of a typical basin, has been urged as a reason why
the Hawkesbury Series should not be of the same age as the
Artesian Series. This argument would, however, apply equally
well to the Clarence Series, which also occurs in the typical basin
form but, as far as is known, contains little or no artesian water.
121
The absence of coal seams in th« Hawkesbury Series has been
similarly cited as a reason for their greater age ; there seems to-
be no valid reason, however, why sedimentation could not go on
in twro distinct basins simultaneously with conditions for coal-
making favourable in the one locality and unfavourable in the
other. At present, therefore, while it may be admitted that
there are some differences between the fossils of the Hawkesbury
Series and the Trias-Jura beds of New South Wales, it is,
perhaps, premature to say definitely that the former were
deposited before the latter.
SUMMARY OF THE TRIASSIC.AND JURASSIC PERIODS.
The close of the Permo-Carboniferous Period, as already pointed
out, was marked in the north-eastern part of New South Wales
by mountain-making (orogenic) movements which folded the
Permo-Carboniferous sediments as far south, approximately, as
the present Hunter River district, where the folding produced
an elevation of at least 7,000 to 8,000 feet. These folded strata
suffered considerable denudation early in the Triassic Period
before the strata of this period were deposited uncomformably
upon them. To the south and south-west of this region no such
earth movements took place, and Triassic sedimentation followed
that of the Permo-Carboniferous Period without any apparent
break. The beginning of the Triassic Period found the whole of
New South Wales above the sea, and extending much further
eastwards than it does at the present time. Certain large areas
remained covered with fresh water, and in the lakes considerable
sedimentation took place ; it will be convenient to call these three
sheets of water the Hawkesbury Lake, the Clarence Lake, and the
Artesian Lake respectively. There is no doubt that the first-named
existed at the beginning of the period, but there is some reason for
thinking that the two latter may not have developed until
somewhat later. The Hawkesbury Lake was essentially the same
sheet of water as that in which the Upper Coal Measures were
deposited, although for a time somewhat restricted in size,
particularly on its northern margin ; in this lake was deposited in
succession the Narrabeen, Hawkesbury, and Wianamatta beds,
with a maximum thickness of about 3,000 feet. As shallow-water
conditions of deposition are in evidence, more or less, throughout
all these beds, the lake-bottom must have been slowly subsiding.
The other two lakes mentioned were in reality parts of an
extensive sheet of fresh water which covered large portions of
southern Queensland and northern New South Wales, and which,
perhaps, extended into South Australia. Parts of this lake
became from time to time vast shallow swamps, in which grew
the vegetation from which the Triassic coal seams were iormed.
122
The great thickness and the nature of the sediments deposited
shows that here, too, a slow subsidence was taking place, while
the coal seams indicate that the subsidence was of an intermittent
nature, each coal seam marking a period of comparative rest in
the downward movement.
In the waters of these lakes fish abounded, while on the
adjacent shores lived the large amphibia, which preyed upon
them. Small Pelecypods (Unio) and Crustacea also inhabited
the lake and river waters. The surrounding country was clothed
with a luxuriant vegetation ; Cycads and Conifers nourished
upon the uplands, while the marshes and swamps supported a
dense growth of ferns and horsetails. The great terrestrial and
flying reptiles, which were such a characteristic feature of the life
of other continents at this time, do not appear to have found their
way into Australia.
CHAPTER XII.
THE CRETACEOUS PERIOD.
STRATA of this age occur over an extensive area in the northern
and north-western parts of New South Wales — an area of upwards
of 70,000 square miles. They are not known to occur in any
other part of the State. No detailed geological surveys have been
made of this area, consequently information regarding the Cre-
taceous formation is somewhat limited. As these Cretaceous strata
are continuous with those of the sam^ period in the adjoining States
of Queensland and South Australia, the information gathered
from these localities will be made use of to supplement that which
has been obtained from New South Wales.
The Cretaceous Formation of Australia has been subdivided as
follows : —
A. The Upper Cretaceous or Desert Sandstone Formation.
B. The Lower Cretaceous or Rolling Downs Formation.
The Rolling Downs Formation. — Although this formation has
been met with in sinking wells and bore-holes in New South
Wales, no surface outcrops have yet been discovered. In
Queensland, however, outcrops occur over extensive areas, par-
ticularly in that part of the southern portion of the State known
as the Rolling Downs. The surface here consists of gently
undulating plains, or rolling downs as they are called, cut out of
strata of Cretaceous age, hence the name. The strata in this
region consist of shales, sandstones, limestones, marls, and
gypseous clays, mainly of marine origin, but including some fresh-
water deposits containing plant remains and thin seams of coal.
The basal beds of the series, which consist of very porous sand-
stones, are known as the Blythesdale Braestones, and have been
referred to by the Queensland Geological Survey as the intake
beds of their artesian-water basin. As already stated, no surface
outcrops of Lower Cretaceous strata have yet been met with in
New South Wales, but considerable thicknesses have been passed
through in sinking artesian wells. The Wallon bore, in the
Moree district, passed through a thickness of 1,500 feet of these
beds, consisting mainly of marine shales, sandstones, and lime-
stones. The bore-hole at Bulyeroi, 60 miles to the south-west,
passed through similar strata 620 feet in thickness. In both
cases the Cretaceous strata were met with only a few feet from
the surface, being covered and hidden by a superficial deposit of
124
Post-Tertiary age. At Yandama Station, in the Milparinka
district, 450 miles west from Moree, strata containing marine
fossils characteristic of this formation were met with in sinking
shallow wells.
Small flows of artesian water have been obtained from some of
these Lower Cretaceous strata, but, as already explained, the
main supplies in New South Wales are being obtained from the
underlying Triassic rocks. So far as is known, no unconformity
exists between the two formations in New South Wales, but in
Queensland a very distinct unconformity is believed by the local
geologists to exist.
The Desert Sandstone Formation. — This gets its name from its
occurrence in the desert regions of the interior of Australia. In
New South Wales the formation outcrops extensively in the
north-western part of the State, and consists of coarse sandstones,
grits, conglomerates, and beds of a fine-grained white siliceous
rock, resembling kaolin in appearance. The sandstones and grits
are the lowest beds of the series, and are of marine origin. In
many localities the sandstone has been altered into an intensely
hard, brittle, porcellanous rock resembling quartzite. This altera-
tion has been brought about by the introduction of secondary
silica, possibly by the action of thermal springs. At some
localities, notably at White Cliffs, there occur above the sand-
stone beds of a very fine-grained, soft, white rock, which in some
places is almost devoid of alumina, and consists of nearly pure
silica, although in other places as much as 25 per cent, of alumina
may be present. Doubtful determinations of Badiolaria and
Diatoms have been made, suggesting the probability of the
rock having an organic origin. The same stratum also contains
numerous fossil marine shells, fragments of fossilised wood, and
the bones of marine reptiles (Sauropterygia). A remarkable
feature at White Cliffs is the occurrence in this bed of numerous
water- worn boulders of a fossiliferous Devonian quartzite, ranging
up to 2 feet in diameter. The origin of these boulders has given
rise to considerable discussion. The exceeding fineness of the
sediments in which they are imbedded precludes the possibility
of transportation to their present position by running water.
Transport by floating ice has been suggested ; the boulders do
not, however, show any glacial striae, and there is a total absence
of any corroborative evidence. It has also been suggested that
they may have been transported entangled in the roots of drift-
ing trees. As Devonian quartzites outcrop about 20 miles to
the westward, where part of the shore-line of the Cretaceous sea
probably existed, and, as fossil driftwood is common in the same
bed as the boulders, there seems to be some probability of this
being the correct explanation.
125
The Upper Cretaceous strata, which
are always horizontal or nearly so,
attain, both in the De Grey Ranges
and at Mount Oxley (near Bourke), a
thickness of about 500 feet. The
formation, as a whole, has been exten-
sively denuded since its deposition, so
much so, that, for the most part, mere
isolated outliers remain of what was
at one time a much more extensive
formation. At Mount Brown, at
Tibbooburra, and near Milparinka, the
basal conglomerates of the Cretaceous,
where they dip away from the Lower
Palaeozoic strata, are auriferous. The
gold has, no doubt, been derived from
reefs traversing these Palaeozoic strata,
and concentrated in the Cretaceous
gravels during the time they were
being deposited.
At White Cliffs in the Wilcannia
district, and at Lightning Ridge, near
Walgett, precious opal occurs in the
Upper Cretaceous rocks. It is of
secondary origin, and occurs as irregu-
lar veins and patches in the white
siliceous rock already referred to. At
the former locality it is quite common
to find marine shells, reptilian bones,
and fragments of fossil-wood wholly or
partly replaced by precious opal. The
quality of the opal obtained is equal
if not superior to that obtained in any
other part of the world, and the value
of the production to date exceeds
£1,237,899 sterling.
The Upper Cretaceous strata in New
South Wales, so far as is known, are
conformable with the underlying Lower
Cretaceous.
Cretaceous Ltfe. — The Cretaceous
flora is represented in New South
Wales collections by coniferous wood
only. In the De-Grey Ranges a grove
of fossil-tree stumps occurs in the
Desert Sandstone formation ; these are
Ill
126
standing in the position of growth, the larger ones having a
diameter of about 4 feet. They must have been covered by the
Cretaceous sediments while still erect, became petrified by infil-
tration of silica, and have been re-exposed since by weathering.
The occurrence of driftwood in some of the marine beds is not un-
common. In Queensland occasional thin seams of coal occur both
in the upper and lower beds, and the fossil leaves of a considerable
number of genera of dicotyledonous plants have been obtained
from fresh-water beds in the same State. There is considerable
probability, however, that these leaf beds are of Tertiary age.
With regard to the fauna, so little collecting has been done
from the New South Wales strata that it will be more satisfactory
to refer to the Cretaceous fauna of Australia as a whole. The
invertebrate fauna, so far as we know it, consists dominantly of
mollusca. Of these, the Pelecypoda are particularly numerous ;
fifty genera and over 100 species have already been described.
The Cephalopoda are also abundant, and with regard to size
dominated all the other invertebrates. Specimens of Crioceras
have been obtained in Queensland, which range up to 2 feet or
more in diameter. The genera Ammonites and Belemnites are
abundantly represented. Gasteropods are only sparingly repre-
sented. Foraminifera are abundant, but no beds of chalk are
known to exist. Crinoids, echinoicls, and sponges do not appear
to have been abundant, while reef-building corals are totally
absent. The vertebrates were represented by fish and reptiles.
The latter belong to the two great cosmopolitan groups — the
Sauropterygia, and the Ichthyopterygia, and appear to have been
numerous. The great terrestrial and flying reptiles, so abundant
in the Northern Hemisphere at this time, were absent, or at any
rate, none of their remains have yet been found.
LIST OF THE MORE IMPORTANT AUSTRALIAN
CRETACEOUS FOSSILS.
PLANTS : — Coniferous Wood.
FORAMINIFERA : — Lagena, Nodosaria, Reophax, Cristellaria,
Haplophragmium , Polymorphina.
SPONGIDA : — Purisiphonia.
CRINOIDEA : — Isocrinus* Pentacrinus.
ECHINOIBEA : — Micraster.
VERMES : — Serpula.
BRACHIOPODA : — Discina, Lingula, Rhynchonella, Terebratula.
PELECYPODA : — Aucella,* Corimyaj* Gucullcea*, Cyrenopsis*
Glycimeris* Inoceramus,* Lima, Maccoyella* Modiola,* Mytilus,
Nucula, Ostrea, Pecten, Pseudavicula,* Tellina* Trigonia*
GASTEROPODA : — Nqtica, &c.
CEPHALOPODA : — Belemnites,* Ammonites, Ancylcceras,* Crio-
ceras, Hamites, Haploceras,* Nautilus, Scaphites.
127
PISCES: — Belonostcinus, Lamna, &c.
REPTILIA: — Cimoliosaurus,* Plesiosaurus, Agrosaurus, Ichthyo-
saurus, Notochdone,.
NOTE. — Those genera marked with an asterisk have been found in
New South Wales,
Fig. 64.
Cretaceous Pelecypoda.
1-2. Maccoyella Barklyi. 3. Trigonia nasuta. 4. Trigonia Maori. 5. Inoceramus, Sp.
6. Aucella Hughendenensis.
128
SUMMARY.
The subsidence which had been taking place during the
deposition of the Trias- Jura fresh- water beds in western New
South Wales and Queensland, finally resulted in an invasion of
the sea from the north, which, at the beginning of the Cretaceous
Period, submerged the greater part of Queensland, a considerable
part of Central Australia, and the north-western part of New South
Wales (see map), and converted the whole of this area into a vast
epicontinental sea. This subsidence continued intermittently
throughout the Lower Cretaceous to an extent of at least 1,500
feet, allowing for the deposition of the Rolling Downs formation,
Fig. 65.
Cretaceous Cephalopoda.
a. Belemnites oxys. b. Ammonites (Haploceras) Daintrei.
c-d. Crioceras Jackil.
129
all the strata of which show more or less evidence of shallow-
water conditions of deposition. The existence of fresh-water beds
and thin seams of coal indicate that parts of this Cretaceous sea
were from time to time temporarily cut off from the main body
and converted into swamps, in which a luxuriant vegetation
flourished.
The unconformity which in Queensland exists between the
Rolling Downs Formation and Desert Sandstone Series, shows
that crustal movements took place after the deposition of the
former, which brought about a temporary retreat of the sea, — at
least over the eastern part of the Cretaceous area. Renewed
subsidence followed during the Upper Cretaceous, and a
re-advance of the sea took place which transgressed in many
places, even beyond the limits of the Lower Cretaceous sea.
The marine fauna of the Upper Cretaceous appears to have been
essentially the same as that of thei Lower ; this, together with the
fact that in other parts of the area the two series are apparently
conformable, may be taken to indicate that the retreat of the sea
did not affect the whole area, and the progress of life continued
uninterruptedly throughout the period.
3910-K
CHAPTER XIII.
THE TERTIARY PERIOD.
THE uplift which closed the Cretaceous Period converted the
whole of existing New South Wales into dry land, and no part of
it, excepting a limited area in the south-western corner, has since
been beneath the sea. Tertiary marine strata are, therefore,
excepting in the small area mentioned, absent in this State.
There is also no evidence for the existence of any large Tertiary
lakes, as lacustrine deposits of any importance are not known to
occur; the only other Tertiary formations found are alluvial
deposits (formed along the Tertiary river channels), lava flows,
and tuffs. This comparative failure of the geological formations
of New South Wales to provide a record of its Tertiary history
is, however, compensated for to a large extent by the evidence
obtained from a study of the development of its present topo-
graphy.
Such Tertiary formations as occur may, from the point of view
of their origin, be subdivided as follows :—
(A) The Eocene (? Oligocene) Marine Strata.
(B) The Fluviatile Deposits.
(C) The Diatomaceous Earth Deposits.
(D) The Volcanic Formations.
A. THE MARINE STRATA.
These occur in tht south-western part of the State, along the
lower courses of the Murray and Darling Rivers ; they consist of
calcareous sandstones and shales containing marine fossils. They
are concealed, for the most part, by more recent superficial
deposits, but outcrop in places in the banks of the above-mentioned
streams. A bore put down at Arumpo proved these beds to be
at least 900 feet in thickness, as at this depth a characteristic
Eocene Pelecypod (Trigonia semiundulata) was obtained. At
Tareena and Mindarie similar beds have yielded abundant
marine fossil shells, including various species of Cucullcea,
Crassatella, Trigonia, Cardila, Ostrea, Fusus, Valuta, Turritella,
and Cerithium. This marine fauna shows a commingling of
species which in other parts of Australia are considered to belong
to distinct Eocene and Miocene faunas. These beds are apparently
co-extensive with marine strata in the adjoining States of Victoria
131
and South Australia, which are by the geologists of those States
referred to the Eocene (? Oligocene) Period, Their presence shows,
Fig. 66.
Tertiary Basalt Flow (Newer Basalt), Guy Fawkes, New England, New South Wales
that the subsidence which affected the southern part of Australia
at the beginning of the Tertiary Period formed a large embayment,
132
Fig. 67.
Map of the South-Western part of New
South Wales, showing- the probable area
covered by the sea in the early part of
the Tertiary Period. (After Gregory.)
whose extent is indicated in the
map shown in Fig. 67. This
transgression of the sea appears
to have come to an end, so far
as New South Wales was con-
cerned, before the beginning of
the Miocene Period.
B. THE FLUVIATILE DEPOSITS.
At many places in New South
Wales old river channels are
found buried between deposits
of alluvium and sheets of basalt.
In these channels are found beds
of fine and coarse river-gravel,
clay, sand, and in some few
cases beds of lignite ; the coarse
gravels usually occur at the
base of the deposit, and in
many cases contain gold, tin-
stone, gem-stones, &c. These
buried gravels are known to
the miners as " shallow leads " and " deep leads." The former
may be defined as the alluvial deposits occurring along existing
stream channels ; the latter as a stream channel whose alluvial
contents are buried beneath a capping of alluvium or lava
(or both). In some cases, as at Kiandra and Bathurst, the old
river channel, with its gravel and basalt capping, is on top of a
hill 500 or 600 feet above the level of the present day tableland.
These have yielded no recognisable fossil plants, and are probably
of early Tertiary age ; the basalt flows which cover and protect
them are believed to be the equivalent of the " older basalt " of
Victoria. These leads are provisionally referred to the Lower
Tertiary (Eocene Period). In other cases, as at Forest Reefs and
Gulgong, the old channels lie beneath the surface of the table-
land, and may be below the level of the adjacent present-day
stream channels. Some of these contain numerous fossil leaves
and fruits derived from a flora which, in its general character,
was similar to the present-day coastal brush vegetation. These
leads are provisionally referred to the Upper Tertiary (Pliocene
Period).
(a) The Lower Tertiary Leads.
The Kiandra Lead. — This occurs on top of a hill adjacent
to the town of Kiandra ; the section in figure 68 shows
it as exposed in the face of New Chum Hill. The
1 .!
-Ill
£111
-8 o
134
materials forming this deposit are as follows (in descending
order) : —
Thickness.
Columnar basalt ... ... ... ... 11 feet.
Earthy lignite 8 „
Yellow and red sands and clays... ... 35 ,,
Lignite (containing tree-stems) ... ... 8 ,,
Red and yellow clay ... ... ... 8 „
Coarse sandy layers ... ... ... 45 „
Red and yellow clay ... ... ... 6 „
Lignite and black shales (containing plant
remains) ... ... ... . , 25 ,,
Earthy lignite ... ... ... ... 4 „
Sand 3 „
Auriferous wash .. 14 ,
This material lies in a well-defined rock channel up to 10 chains
in width, and has been traced for a distance of about 2U miles ;
there can be no doubt that it is an old river channel. This deep
lead has been cut across in several places by the present-day
streams, thus exposing good sections of it in their valley walls.
The Bathurst Lead. — This occurs on the top of the Bald Hills,
adjacent to the town of Bathurst ; the basalt capping has a
thickness of about 200 feet, and almost directly overlies the
quartz pebble wash. Between the two, on the north side of the
hill, there is a deposit of white clay about 10 to 12 feet in
thickness. The only fossils recorded from this lead are fragments
of silicified wood. The bed of this old river channel is about
550 feet above that of the present day Macquarie River.
(b) Upper Tertiary Leads.
Vegetable Creek Leads — These are in nearly all cases covered
by basalt, in some places two distinct flows occur, separated by a
small thickness of sand and clay. The Hume Lead at the Wesley
Mine gave the following section : —
Red sandy soil ... ... 10 feet in thickness.
Basalt 8J „
Tuff and scoriae ... ... 51 ,,
Basalt flow 2l|
Do 73
Sands and clays ... ... 22 „
Stanniferous gravels ... 3J „
All of the leads in this district are stanniferous (tin-bearing),
the tin occurring iji the form of water- worn grains of oxide of
tin (cassiterite). . Fossil plants are not uncommon in them, and
135
include varieties of oeech, oak, banksia, grevillia, laurel, and
eucalyptus.
Many of the leads on the New England tableland, besides
being stanniferous, contain gem-stones, such as diamond, sapphire,
zircon, topaz, &c.
ft. in.
13 0 Yellow clay.
10 6 Yellow clay with sand
9 0 Yellow and white sand.
14 0 Fine and coarse drift.
54 0 Yellow clay with stones.
1 6 Rotten slate.
16 6 Eed clay.
8 6 Red clay with stones and slate.
20 6 Red clay with stones.
44 0 Red and yellow clay.
2 0 Rotten or decomposed slate.
193 6
Fig. 63.
Section of one of the " Deep Leads" at Forbes, New South Wales. (Andrews,
The Leads of the Parkes-Forbes District. — The leads of this
district include both shallow and deep leads, the former in many
instances merging down stream into the latter. They are
auriferous, the gold occurring (a) along the gutters of the main
channels, and associated with the coarser stream deposits ;
136
(b) along the rim rocks or the sides of the buried stream channel ;
(c) in various irregularly arranged patches of coarse stream
material situated above the older and deeper buried stream
channels. In Fig. 69 is a section of a bore-hole put down
through one of these alluvial deposits. These leads, unlike
those in many other parts of the State, are not capped with
basalt. Mr. E. C. Andrews, in his report on the Parkes- Forbes
gold-field, gives the following history of the formation of these
deposits : —
"(1,) The land was raised, and a series of 'valley in valley '
forms were excavated by the Lachlan tributaries. Along the
steep channel bottoms gold was deposited by the rapid streams,
for during the process of wearing the country down, the lodes
contained therein were also broken down, and their auriferous
contents washed down and lodged in the channels of these old
streams.
" (2.) After the formation of these rock channels the land sank,
and the rock-bound watercourses, instead of being deepened,
were at this stage gradually filled up. The gold contents became
poorer in these upper alluvial deposits ; firstly, because the gold
reefs were being buried in part ; secondly, because the streams at
this stage had not the power to carry the coarser gold as far as
formerly ; and, thirdly, because the gold was distributed through
a vast width of alluvial debris, instead of being concentrated
near the bottom of a narrow gutter.
" (3.) After the filling of the well-defined channels, the alluvial
began to overflow the rock rims of these old watercourses, and to
bury the lower portion of the main Lachlan valley. The streams
at this stage ran in no well-defined channels, except locally, and
gold was naturally jigged and deposited upon the channel sides
and also bottoms.
" (4.) The land to the east of Forbes appears to have risen con-
siderably at this stage, and heavy masses of coarse drift were
laid down upon the clay and sand beds by swiftly flowing streams.
As the strength of the stream decreased, the black soil plains
were deposited in turn upon the coarse drift."
The Gulgong Leads. — The alluvial deposits in these leads range
from a few feet up to 200 feet or more in thickness, and are
covered in some cases by basalt flows ranging up to 130 feet in
thickness. These leads were very rich in gold, and in seven
years (1869-1876) produced about 16 tons of this metal ; the
gold was derived from the denudation of the reefs in the sur-
'rounding Silurian strata. In these deposits abundant fossil
'leaves and fruits were obtained, as well as the bones of
marsupials, some of which belonged to extinct species of large
size.
137
The Forest Reefs Leads.—Thesti occur beneath the basalt flows
which form the capping of the tableland in the Orange district.
They are similar to the Gulgong Leads, and contain fossil fruits
and leaves ; they, too, are auriferous.
C. THE DIATOMACEOUS EARTH DEPOSITS.
These occur at widely distant localities, such as Coonia,
Canobolas Mountains, Warrumbungle Mountains, Barraba,
Wyralla (Richmond River), £c. The deposits are in no case
very extensive, and appear to have resulted from the accumu-
lation of the frustules of diatoms and the spicules of sponges in
small fresh-water lakes and lagoons. Nearly all of these deposits
are associated with Tertiary igneous rocks, those at , the
Warrumbungle Mountains being interstratified with trachytic
lavas and tuffs. The following are analyses of material from
some of th^se deposits, from which it will be seen that the
diatomaceous earth is of good quality : —
Coonia.
Parraba.
Warrumbungle
Mountains.
.
Wyralla.
Si02
8T64
80-56
82-62
86-01
Fe20s
A1,0S
CaC08
0-40
3-20
1 -50
1-77
4-15
0-31
j 5-20
9-53
2-83
Not deter-
MgCO,
H20
2-16
10-95
0-21
P2-S4
0-70
10'96
mined,
do.
5'48
The diatoms which they contain belong mainly to the genus
Melosira, and with these are associated the spicules of a fresh-
water sponge (Spongilla). Impressions of the leaves of dicoty-
ledonous plants and of fern fronds (Pteris] are frequently found
in these deposits.
D. THE VOLCANIC DEPOSITS.
Three distinct volcanic epochs seem to have occurred in New
South Wales in the Tertiary period ; two of these were productive
of basaltic lavas only, but the third and latest produced a most
interesting series of alkaline lavas and tuffs. The actual geological
ages of these volcanic epochs will be discussed later ; they may
be referred to as follow : —
The Alkaline Lavas and Tuffs.
The Newer Basalts.
The Older Basalts.
138
<D
II
1 1
—
I
33
ns
CD
•t+4- +
•-M-
It
a II
1. The Older Basalts. — These sur-
vive as cappings on some of the
residuals, which rise in the form of
isolated hills (Monadnocks), or long
narrow ridges, above the surface of
the Great Eastralian Tertiary pene-
plain. River gravels underlie these
basalt flows at many localities. The
basalt capping the Kiandra lead, as
shown in figure in the previous
chapter, belongs to this period, as
also does that capping the Bald
Hills near Bathurst (Fig. 70) ; the
basalt cappings on some of the
peaks arising above the level of the
surface of the Blue Mountain table-
land also probably belong to this
epoch. These basalts flowed down
the valleys which occurred on the
surface of a (?) Cretaceous pene-
plain, thus covering the river
gravels. How extensive these flow&
were it is now impossible to esti-
mate, as what we see to-day are
mere isolated remnants both of the
basalt and the peneplain upon which
they rested.
The Newer Basalts. — These occur
as extensive sheets (flows), resting
in many places upon the surfaces of
the tablelands of New South Wales.
This series has its greatest develop-
ment on the New England table-
lands, covering there many hundreds
of square miles in the neighbourhood
of Inverell, Glen Innes, Armidale,
Walcha, and other localities. On
the Central tableland they have
a considerable development in the
Orange-Blayney and Oberon dis-
tricts, while on the Southern table-
land they are extensively developed
between Cooma and Bombala.
Many of these basalt flows appear
to have resulted from fissure erup-
tions, as we seldom find anything in
the nature of volcanic cones in the
139
districts in which they occur, while associated tuffs are rare. In
the Vegetable Creek district the flows range up to 300 feet in thick-
ness, and here beds of tuffs ranging up to 40 feet in thickness do
occur ; these latter are now much altered, and are known as laterite.
The Alkaline Lavas and Tuffs. — These are not widespread in
their distribution, like the basalts, but occur in the form of groups
of extinct volcanic cones, coveting in each case a limit area. The
Canobolas Mountains, near Orange, the Warrum bungle Moun-
tains, near Coonabarabran, and the Nandewar Mountains, near
Inverell, are the best known of these occurrences. The Canobolas
Mountains cover an area of about 10 miles square on the western
edge of the Central tableland, near Orange ; the tableland here
has an elevation of about 3,000 feet, and the volcanic series of
the Canobolas Mountains rest upon the surface of this tableland,
and rise to a maximum altitude of 4,610 feet, i.e., about 1,600
feet above the tableland level.
The first eruption brought to the surface a series of highly acid
and alkaline lavas called Comendites( Alkaline Trachytic-Rhyolites)
and Alkaline Quartz-Trachytes ; these built up a number of steep
lava cones. The next series of eruptions produced alkaline-
trachytes and extensive beds of tuff of somewhat similar com-
position ; while still later eruptions produced alkaline andesites of
a somewhat basic type. The order of eruptions was as follows : —
1. Comendites and Quartz Trachytes.
2. Alkaline Phonolitic Trachytes.
3. Andesites.
A sequence which shows increasing basicity.
The alkaline rocks of the Warrumbungle and Nandewar
Mountains closely resemble those of the Canobolas Mountains
both in chemical composition and lithological characters, while the
sequence of eruption was the same in all these localities. Analyses
of these rocks are given on page 169.
THE TERTIARY FLORA.
As has already been mentioned, numerous fossil fruits and
leaves have been obtained from some of the Tertiary leads.
Those at Forest Reefs and Gulgong, in particular, have yielded a
large number of fossil fruits, which include the genera Plesiocap-
paris, tipondylostrobus, Penteunt, as well as numerous others.
A large number of fossil dicotyledonous leaves have been
obtained from the Deep Leads at Gunning, Forest Reefs, Emma-
ville, &c., and have been referred to such genera as Alnus,
Quercus (Oak), Fagus (Beech), Cinnamomum, Laurus (Laurel),
Magnolia, Bombax, Pittosporum, Eucalyptus, Banksia, and
Grevillia. This flora has been described as containing represen-
tatives of the existing floras of many other parts of the world, and
140
to be entirely different to that now occurring in Australia. Both
the generalisation and the generic and specific determinations upon
which it is based are open to serious question. It has been shown
that it is unnecessary to seek outside of Australia for the types
of our Tertiary fossil plants, as they are to be found in the luxuri-
ous flora now confined to strips and patches along the coast, where
there is a warm climate and an abundant rainfall. The Tertiary
representatives of this present day coastal " brush " flora have a
very wide distribution, occurring from Tasmania to Queensland,
and as far west, at least, as Orange. These regions, some parts
of which are now relatively cold, and other parts relatively dry,
must have had a warmer and moister climate during the Tertiary
Period in order to have supported such a vegetation, it will be
shown in the next chapter that the present tableland regions of
East Australia were preceded by an extensive peneplain elevated
but little above sea-level, the only highlands then existing being
isolated hills and long narrow ridges, few, if any, of which reached
an elevation of 1,000 feet. Under such topographical conditions
this region would have, it is considered, a more or less uniformly
warm and moist climate which would be capable of supporting
such a " brush " vegetation as appears to have covered it in Upper
Tertiary times. The Tertiary flora, then, while differing to a
considerable extent from that of f^he present tableland regions, with
their relatively cold climate, and of the western slopes and plains
with their hot and semi-arid conditions, was, taken as a whole,
not very different from our present day coastal " brush " flora.
THE TERTIARY FAUNA.
The dominant group of land animals during this period was, as
is the case at the present day, that group of the Mammalia known
as the Marsupialia ; the Monotremes were also well represented,
but none of the higher mammals (Placental Mammals) were
present. The following is a list of tae more important land animals,
of the Tertiary Period :—
C Diprotodon.
Nototherium.
Phascolonus.
| Phascolomys (Wombat).
( Marsupialia •{ Thylacoleo.
I Thylacinus (Tasmanian Tiger).
I Sarcophilus (Tasmanian Devil).
f; | Macropus (Kangaroo).
^Ualmaturus (Wallaby).
VERTBBBATA -{ Mnnotrftrnpst J Echidna.
BS / Ornithvrhynchus (Platypus).
Aves (birds) Dromornis, &c.
( Megalania (Giant Lizard).
LReptilia 1 Chelodina.
( Meiolania (Turtle).
142
Some of the genera listed above are now extinct, and those
which survive are represented, for the most part, by different
species. As compared with their present-day representatives, the
Tertiary vertebrates were characterised by their larger size ; not
that small species did not exist, but that many which then lived
were larger than any existing to-day. The largest of all was the
Fig. 72.
Skull of Diprotodon Australia. (After Owen.)
genus Diprotodon, a marsupial as large as a rhinoceros, and which
walked on all-fours ; its skull in some cases was over a yard in
length. This huge extinct marsupial lived in large numbers even
in the far western parts of the State, where, under existing
conditions, they would die of starvation and thirst. This supports
the evidence given by the Tertiary plants that the climate was at
that time moister than at present, arid that the land was clothed
with a luxuriant vegetation.
Nototherium was also of large size, quadrupedal in habit,
and resembled in general appearance a large tapir. The wom-
bats (Phascolomys) were much
larger than their present-day
descendants, as also were the
kangaroos (Macropus] and
wallabies (Halmaturus). Car-
nivorous marsupials, which do
not now exist on the mainland
of Australia, were represented
by the two living Tasmanian
genera Thylacinus (Tasma-
nian tiger) arid Sar^ophilus
Skull of Thylacoleo carmfex. (After Owen.) _ ». / . ... , " ,
(Tasmanian Devil), but here
again by larger species. The disappearance of these two genera
from the mainland was, possibly, due to the advent of the dingo
143
(Canis Dingo), probably introduced into Australia by the present-
day aborigines. Thylacoleo (Marsupial Lion) is another fossil
marsupial, said to have been carnivorous in habit, but there is
considerable difference of opinion upon this point.
Genyornis and Dromornis, the largest of the Tertiary birds,
somewhat resembled the present-day Emu, but were larger. The
present-day Monotremes — Echidna and Ornithorhyncus — were
also represented by larger species, while the Reptilia included
lizards and turtles.
Many of the Tertiary vertebrates which are now extinct
possibly still lingered on into the early part of the Pleistocene
Period, and their extinction, particularly in the case of the larger
herbivorous forms, probably resulted directly or indirectly from
the climatic changes which followed the extensive uplift that
closed the Tertiary Period.
The Marine Fauna. — A list of the more important genera has.
already been given on page 130. All the genera still survive-
in our present seas, although the majority of the species are
extinct. This fauna consisted dominantly of Pelecypods and
Gasteropods.
ECONOMIC IMPORTANCE OF THE TERTIARY
FORMATIONS.
As has already been pointed out, many of the Tertiary
fiuviatile deposits contain substances of economic value ; these
include gold, platinum, tinstone, and precious stones. Of the
total gold (value £60,000,000) and tin (value £8,750,000) pro-
duced in New South Wales to date, considerably more than
one-half has probably been obtained from these alluvial deposits.
The Tertiary basalts have, by their decomposition, produced much
of the best agricultural land in the State, and thus indirectly
added to the national wealth to a greater extent even than the
gold and tin-bearing alluvial deposits.
THE DEVELOPMENT OF THE PRESENT
TOPOGRAPHY.
The information regarding the history of the Tertiary Period
in New South Wales, obtained from a study of its Tertiary
formations, is very meagre, and it is desirable to supplement it
as far as possible from other sources. A study of its present
topography supplies much important information. No part of
the State, except one very small area, has been beneath the sea.
since the Cretaceous Period, while the major portion has not
144
been beneath the sea since the end of the Palaeozoic era. Con-
siderable areas (see Fig. 61), however, were covered by fresh-
water lakes in the Trias-Jura Period. The present topographical
features, therefore, have been in course of development since as
far back, at least, as the Trias-Jura Period over all parts of the
State, except the area covered by the Cretaceous sediments in the
northern and north-western regions and the small area covered
with Eocene marine strata in the south-eastern corner.
The surfaces of the various tablelands forming the highlands of
New South Wales and of the low plateaux of the central-
western areas are all parts of one and the same peneplain, cut
indiscriminately out of strata varying from pre-Cambrian to
Trias- Jura in age. As to whether this same feature extends into
the Cretaceous area of the north-west is not known to the author,
but it is thought that it probably does. This peneplain was
uplifted at the close of the Tertiary Period to form the existing
tablelands ; it was probably developed during the Tertiary Period.
As it occurs throughout the whole of Eastern Australia, the
name " Great Eastralian Peneplain " would be an appropriate one
for it, arid will, therefore, be used here.
Resting upon the surface of this peneplain in many places are
extensive sheets of basalt (the newer basalt) ; these lava flows
were obviously poured out after the peneplain surface had been
developed. They cover, in many localities, old river channels
(deep leads), such as those at Gulgong and Forest Reefs, whose
valleys, which seldom exceed 300 feet in depth, and their con-
tained alluvial deposits are, of course, also younger than the
peneplain. It is these leads which contain the fossil leaves and
fruits referred to on page 139. The surface of the peneplain is
not flat, but is traversed in most places by a network of broad,
shallow, mature valleys, ranging from 150 to 300 feet in depth ;
these have been cut out of the basalts as well as out of the older
rocks, and are, therefore, younger than the basalts.
Rising above the general level of the Great Eastralian
Peneplain there are numerous isolated hills and long narrow
ridges. They consist, in some cases, of tilted Palaeozoic strata ;
in others, of plutonic igneous rocks ; while others, again, are
made up of nearly horizontal Triassic strata. In any one district
the highest of these residuals all rise to about the same altitude
above the peneplain level, showing that they are residuals of an
older tableland, the surface of which was also a peneplain. This
older peneplain was probably cut out during the Cretaceous
Period. It will be convenient to refer to it as the Cretaceous
Peneplain, it being understood, however, that the age assigned
to it is provisional. On the Yass-Canberra tableland the
residuals of the Cretaceous Peneplain rise to a height of from
145
600 to 850 feet above the level of the Great Eastralian Pene-
plain, indicating that the tableland which preceded the present
one in this region had a minimum height of about 850 feet.
Many of the residuals of the Cretaceous Peneplain are capped by
basalt flows ; these have been referred to on a previous page as
the Older Basalts : the river gravel underlying them contain,
as far as is known, no recognisable fossils.
146
The succession of events which produced these topographical
features, with the ages provisionally assigned to them, may have
been somewhat as follow : —
Cretaceous. —
A cycle of erosion which produced the older peneplain,
followed by an epeirogenic uplift, which converted
the peneplain into a tableland, and ushered in the
Tertiary Period.
Lower Tertiary. —
(a) Volcanic eruptions, which brought to the surface
basalt flows — the Older Basalts.
(b) A cycle of erosion, which produced the Great
Eastralian Peneplain.
Upper Tertiary. —
(a) A slight uplift, followed by renewed volcanic
activity, with the pouring out of vast sheets of
basaltic lavas — the Newer ^Basalts.
(b) Development of the shallow mature valleys now
occurring on top of the tablelands.
(c) Volcanic eruptions at several centres, which were
productive of The Alkaline Lavas.
Kosciusko Epoch. —
(d) Great epeirogenic uplift, which produced the existing
tablelands, and ushered in the Pleistocene Period.
This uplift was accompanied by normal faulting on
a large scale.
Pleistocene to Recent. —
The existing cycle of erosion, during which the table-
lands produced by the late Tertiary uplift have
been partly dissected.
SUMMARY OF THE TERTIARY PERIOD.
The earth-movements which closed the Cretaceous Period
brought about (1) a retreat of the epicontinental sea which had
previously covered the north-western part of the State; (2) a
transgression of the sea which covered a relatively small area in
the south-western corner; (3) converted nearly the whole of New
South Wales into a tableland, which in the eastern part ranged
from 600 to perhaps 1,000 feet in altitude.
Very early in the Tertiary Period volcanic eruptions began,
from which basaltic lava- flows poured down the then river
valleys, covering up the layers of sand arid gravel (and in some
cases, lignite) which occurred in them (the Older. Leads). These
147
basalts are probably the equivalents of the " Older Volcanics " of
Victoria, which are associated there with Lower Tertiary marine
strata, and which also in some cases overlie lignite deposits.
Owing to the absence of recognisable fossils in these older leads,
nothing definite is known of the terrestrial fauna and flora of this
time. Long continued erosion during the Lower Tertiary Epoch
removed almost entirely the tablelands formed at the close of the
Cretaceous Period, and cut out of it the Great Eastralian Peneplain.
A small uplift at the beginning of the Upper Tertiary Epoch
brought about a retreat of the epicontinental sea which had
previously covered part of the south-western region of New South
Wales. This small uplift enabled the rivers to entrench them-
selves in their old valleys, and bring about the formation of the
" Upper Tertiary Leads," in which are preserved abundant remains
of the Upper Tertiary plants and land animals. A study of these
fossils, as has already been shown, indicates that the whole of the
State at this time enjoyed a warm, moist climate, and was clothed
with a dense sub-tropical vegetation, very different to that which
now covers much of it, but similar to the present-day coastal
" brush " vegetation. The dominant land animals then, as now,
consisted mainly of marsupials, but included also monotremes,
reptiles, large birds, &c. ; all of these had representatives larger
than any living to-day. The larger size of many of the Tertiary
Vertebrata, the large numbers of them which seem to have
inhabited what are now the more arid parts of the State, and the
fact that some of these larger marsupials were apparently quite
unfitted to travel long distances in search of food, suggests that
a luxuriant vegetation existed at the time they lived, even in the
far western parts of the State. A much more regular and more
abundant rainfall must therefore have existed over what are now
the drier parts of the State, during the Upper Tertiary Period,
while owing to the absence of high mountains and tablelands, the
climate of the whole State must have been sub-tropical as well as
moist. This latter fact is borne out by finding the leaves of sub-
tropical plants in the Upper Tertiary Leads occurring on the high
tablelands which now have a relatively cold climate.
Before the Upper Tertiary Epoch was far advanced, great
sheets of basaltic lava (the newer basalts) were poured over the
peneplain surface, particularly in the eastern part of the State, in
most cases, apparently, from fissure eruptions ; these buried many
of the river channels, thus forming the Upper Tertiary Deep
Leads, and preserving the fossil animals and plants which these
river deposits contain.
This volcanic phase was followed by a considerable period of
erosion, during which the broad, shallow, mature valleys were cut
both out of the basalts and the peneplain upon which they rest.
148
Immediately preceding the great uplift which closed this period
active volcanoes broke out at several centres, from which highly
alkaline lavas and tuffs were poured out, and which built up
groups of volcanic cones such as the Canobolas, the Warrum-
bungle, and the Nandewar Mountains.
Close of the Tertiary Period — Roeciusko Epoch. — -This was
marked by an epeirogenic earth movement of considerable magni-
tude, as a result of which the whole of the eastern part of
the State was uplifted so as to form the existing ta.blelands ; it
ranged in amount from 2,000 to 6,000 feet. This uplift was
accompanied by extensive normal faulting and warping, some of
the faults having a vertical throw of at least 3,000 feet. The
more important, and the greater number of these faults and
warps, strike approximately north and south, but east and west
faults and warps also occur. The development of these faults
produced a series of great fault blocks, the surface of each of
which is part of the Great Eastralian Peneplain. In some
localities as, for example, at Cooma and at Jindabyne, relatively
narrow fault blocks are bounded on either side by much higher
blocks, thus forming " Rift Valleys," or Senkungsf elder. These
movements brought about considerable modification of the
drainage systems and of the main divides. For the period of
time during which these earth movements were taking place,
the name Kosciusko Epoch has been suggested by Mr. E. C.
Andrews.
The western parts of the State were also uplifted at this time,
but to a much less extent, ranging up to 800 feet — in no case
exceeding 1,000 feet.
CHAPTER XIV.
PLEISTOCENE PERIOD.
THE close of the Tertiary Period (Kosciusko Epoch) was
marked by that great epeirogenic uplift referred to in the last
chapter, which produced the existing tablelands. This uplift did
not bring to light any of the marine deposits which must have
been forming along the eastern coast during the Tertiary Period.
It is probable, therefore, that the shore-line extended further to
the east then than it does now, and that the coastal strip of the
Tertiary land subsided during the Kosciusko Epoch coincidently
with or immediately after the uplifting of the tablelands, and
was separated from them by a line of faulting and warping,
corresponding approximately in position with the present
shore-line.
The cycle of erosion initiated by the Kosciusko uplift is still in
progress, and has not yet reached maturity. The streams,
rejuvenated by the uplift, held their courses against the rising
land, and have, for the most part, entrenched themselves in their
old channels. They have cut deep gorges and valleys into the
tablelands, but have only partly dissected them, the central parts
of the tablelands being still more or less intact. The faulting and
warping, which accompanied the uplift, did. however, produce
some important modifications of the Tertiary drainage systems —
as, for example, the capture of a considerable part of the original
watershed of the Snowy River by the Murrumbidgee River.
The Kosciusko uplift profoundly modified the Tertiary climate
and the Tertiary fauna and flora. Where there had previously
been level low- lying land, extending more or less over the whole
State, there was now developed a continuous belt of great table-
lands, 2,000-6,000 feet in altitude, paralleling the coast from Vic-
toria to Queensland, and entirely cutting off the but-little-elevated
western region (the Western Plains) from the coast. The eastern
tablelands, owing to their greatly increased elevation, would of
necessity develop a colder climate ; the western regions, on the
other hand, have developed a semi-arid climate, owing probably
to the cutting off of the moisture-laden winds from the Pacific
Ocean by the introduction of the great north and south table-
land barrier.
The first important effect of these geographical and climatic
changes was to profoundly modify the Tertiary flora. Plants
like Quercus, Fagus, Cinnamomum, Magnolia, and Laurus died
151
out, excepting in the moister warm coastal areas, while a much
hardier vegetation, consisting predominantly of Eucalypts and
Acacias, took their place. The genus Eucalyptus in particular
marvellously adapted itself both to the colder climate of the
high tablelands and the drier climate of the interior, and evolved
a very large number of new species.
This modification of the Tertiary vegetation reflected adversely
upon the vertebrate animals, bringing about the extinction of
many of the Tertiary genera and species, particularly those of
large size, such as Diprotodon, Nototherium, &c., and the large
Tertiary species of kangaroos, wallabies, and wombats.
PLEISTOCENE DEPOSITS.
The abrupt change in elevation in passing from the high
eastern tableland to the low-lying western plains has resulted in
the latter forming a base-level for the denudation of the former.
The western rivers draining the tableland overflow their banks
during flood time, when they enter on to the western plains, and
have formed extensive alluvial deposits on their flood-plains.
Westward the flood-plains of neighbouring rivers become co-
extensive, forming great "Piedmont" plains, such as the " Black-
soil Plains " of the north-west, and the " Riverina Plains " of the
south-west. These deposits range up to several hundreds of feet
in thickness, and represent the waste of the tablelands since the
beginning of the Pleistocene Period, and are still being added to.
Some of the shallow leads along the western margin of the table-
land region probably also belong to this period.
East of the main divide, denudation was the dominant feature
during the Pleistocene Period, but alluvial deposits along the
lower courses of some of the larger rivers, such as the Hunter
and the Clarence, began their formation during this period.
THE GLACIAL EPOCH.
Australasia, in common with Europe and North America, had
its " Glacial Epoch " during the Pleistocene Period. On the
mainland of Australia, the refrigeration of the climate was only
of sufficient amount to produce glacial conditions over one very
small area, viz., the Kosciusko tableland. This is the only
surface of any extent in Australia which has an altitude of
upwards of 5,500 feet — the downward limit of the ice-action in
the Kosciusko region during this period. A few other paints in
the neighbouring parts of New South Wales and Victoria project
above this level, but are too small in area to have afforded a
gathering ground for snow and ice. Extensive areas in the
highlands of Tasmania and New Zealand, however, supported
extensive ice sheets and glaciers at this time.
152
The Kosciusko tableland affords evidence of two distinct ice
invasions. The evidence for the older of these consists of —
(1) U-shaped glaciated valleys.
(2) Hanging valleys.
(3) Truncated spurs.
(4) General smoothing of rock surfaces.
(5) Morainic material.
(6) Alluvial flats, representing aggraded glacier lakes.
Fig. 76.
Lake Cootapatamba, Kosciusko Tableland, showing characteristic Glacial Topography.
This visitation consisted of an ice-sheet extending over an area
of from 80 to 100 square miles, and with a maximum thickness
of not less than 1,000 feet. The downward limit of the ice
appears to have been about 5,500 feet. During this time the
snow-line must have been fully 3,000 feet lower than it is now,
which would mean a lowering of the present mean annual
temperature by about 10° Fah.
Professor David has estimated that this ice-sheet existed from
100,000 to 200,000 years ago.
Still more recently, probably about 10,000 years ago, a second
but less extensive glaciation took place in the same region. At
this epoch, a number of valley glaciers developed, ranging up to
153
500 feet in thickness,
but not more than a
mile or two in length.
The evidences left by
these valley glaciers
consists of —
(1) Lateral and Ter-
minal Moraines.
(2) Glacier Lakes.
(3) Glacial Erratics.
(4) Glaciated Pave-
ments and Roches
Mou tonnes.
The glacier lakes
include the Blue
Lake, Lake Albina,
and Lake Cootapa-
tamba. The two lat-
ter are moraine lakes ;
but the first - named
lies in a true rock
basin, with a termi-
nal moraine at its
lower end.
RECENT EARTH
MOVEMENTS.
A study of the
physiography of the
present coast affords
abundant evidence of
a recent subsidence
having taken place.
Similar evidence oc-
curs along the whole
coast of Eastern Aus-
tralia. Such inlets
as Port Jackson,
Botany Bay, Broken
Bay, and many others
along the coast, are
drowned river val-
leys, the amount of
drowning indicating
a subsidence of about
200 feet. Numerous
•8 »
3 .
? S
| •£
c3 ^
03 ~
<u js
js 33
II
I 2
1
3
154
coastal lakes and lagoons, such as Lake Illawarra, Tuggerah
Lakes, Lake Macquarie, exist. These, too, are drowned valleys,
which have more recently been cut off from the sea. Other
features of the shore-line, such as the continental islands (these
are more numerous on the Queensland coast), the bold headlands,
and the deep water inshore afford additional evidence of this
subsidence.
A closer study of the coast affords evidence of a still later
movement of the earth's crust — one of uplift. This uplift was
only of small amount, about 10—20 feet. In some of the more
sheltered bays and estuaries the sea-bottom has been lifted a few
feet above sea-level over limited areas. Islands produced by the
previous subsidence have in this way been rejoined to the land,
thus forming tied islands or tombolas.
Further evidence for this recent uplift is given by the " raised
beaches" of the Hunter River delta, near West Maitland.
Estuarine beds, containing marine shells, occur here at heights
of as much as 15 feet above high- water mark — this is shown in
the accompanying section. At Largs this estuarine deposit has
yielded upwards of thirty species of living marine shells.
CHAPTER XV.
THE IGNEOUS ROCKS OF NEW SOUTH WALES.
FREQUENT reference has been made in previous chapters to the
igneous rocks of the different geological periods ; it will, perhaps,
serve a useful purpose to summarise, in this chapter, our present
knowledge of these igneous rocks.
The most satisfactory method of treating this branch of the
Geology of New South Wales would be to consider the intrusive
and volcanic rocks together, and show their relationships from
both a chronological and a petrological standpoint. So little
work has been done in correlating these two groups of rocks,
however, that the available information is too meagre to allow
of this being done ; each group, therefore, will be dealt with
separately.
A. — INTRUSIVE ROCKS.
"Very little systematic research work has yet been carried out
with regard to the intrusive igneous rocks of this State, and our
present knowedge, therefore, is so limited that broad generalisa-
tions are almost impossible ; consequently many of the conclusions
put forward here must be looked upon as being quite tentative.
From the point of view of age, these rocks fall naturally into two
groups (a) those of Paleozoic Age, (b) those of Cainozoic Age.
During the Mesozoic Era, both plutonic and volcanic activities
appear to have been dormant.
(a) Palaeozoic Intrusive Rocks. — The intrusion of large plutonic
masses of igneous rock, during this era, seems to have been
definitely related to important crustal movements of the erogenic
type ; each mountain-making epoch appears to have been a time
of plutonic activity. The most important of these epochs appears
to have been that which closed the Devonian Period (the
Kanimbla Epoch), when intrusions of granite and allied rocks took
place on a grand scale. That the earlier Palaeozoic mountain-
making epochs had their plutonic intrusions is most probable,
but at present we have but little knowledge of them. The
gneisses which form part of the Metarnorphic Series of the
Cooma district, as also those which occur in the Barrier district,
are probably altered granites, and are almost certainly of pre-
Cambrian age. Some of the hornblende and augite-porphyrites,
associated with the Ordovician strata, appear to be intrusive and
to be of pre-Silurian age.
156
Acid plutonic rocks are extensively developed over the southern
and central tableland areas of New South Wales (see map).
Many of these are definitely known to be of Kanimbla age ; none
are younger, some are probably older. As the age of many
of these occurrences is uncertain, it will be more convenient
to consider all of them together. They range from acidic
to intermediate in composition, and include granites, tonalites,
quartz-mica-diorites, grano-diorites, and quartz-porphyries.
Highly acidic granites are uncommon, the grey varieties con-
taining hornblende and biotite being the prevailing type ; some
of these so-called granites are really tonalites or grano-diorites.
These plutonic rocks occur in the form of bosses and bathyliths,
many of which are of large size and contain a considerable variety
of rock types. The one which outcrops in the Kanimbla Valley
may be taken as an example; at Old Hartley the rock is a
porphyritic granite, light in colour, almost free from ferro-
magnesian minerals, and contains numerous phenocrysts of
orthoclase ; at Lowther, on the other hand, the rock is much
more basic, contains much hornblende and biotite, is non-
porphyritic, and is very dark in colour ; while on Cox's River
(near Delaney's) a typical quartz-mica-diorite occurs. As to
whether these distinct rock-types represent separate intrusions,
or are due to magmatic differentiation in the magma after it had
been intruded, cannot be stated until these occurrences have been
systematically mapped and studied. Between Cox's River and
Lowther (on the way to the Jenolan Caves) extensive segrega-
tions of aplitic and pegmatitic granites may be seen in the road-
outtings ; these are associated with the more acidic granites. A
similar granite bathylith in the Bathurst district outcrops over
an area of at least 450 square miles.
In the north-eastern part of the State (New England ),orogenic
earth-movements occurred later in the Palaeozoic Era than
elsewhere in New South Wales, and successive igneous intrusions
took place at intervals during the Carboniferous and Permo-
Carboniferous Periods. The chronological succession of these
intrusions was probably as follows : —
1. (?) Carboniferous. — The Dark Felspar Porphyries.
2. Carboniferous (end of).— The " Blue Granite."
3. Permo Carboniferous. —
(a) Middle of the Period — The " Sphene-Granite Por-
phyry."
(b) Close of the Period— The Acid Granites (the Tin
Granite).
The " Dark Felspar Porphyries " occur from Ballendeen, in
Queensland, to as far south as Armidale, and outcrop extensively
around Tenterfield, Emmaville, Glen Innes, and elsewhere ; they
157
are the oldest of the New England
series, but their exact age is not
known. The "Blue Granite" occurs
as large bosses and bathyliths at
many and widely separate localities,
such as Tenterfield, Bolivia, and
Deep water ; biotite is a constant
constituent, and the rock has a
bluish colour, hence its name. The
" Sphene-Granite Porphyry" has an
even wider distribution than the
former, occurring, as it does, at
intervals over an area of about 1,600
square miles, extending from Wal-
langarra (Queensland) to Bolivia.
This rock consists of large porphy-
ritic crystals of orthoclase, set in a
matrix of quartz, felspar, and horn-
blende, frequently with numerous
visible crystals of sphene. It con-
tains a wonderful development of
basic segregations, and makes a very
handsome ornamental stone when
polished ; it intrudes the " Blue
Granite." Large massifs of a very
acid granite, which intrudes both the
*' Blue Granite" and the "Sphene-
Granite Porphyry," are found over
the whole of New England, but with
their maximum development to the
north. An extensive development
of greisen and pegmatite occurs about
the peripheries of these acid intru-
sions, and with thetn are associated
important ore deposits containing
tin, bismuth, tungsten, molybdenum,
and monazite. All of the above-
mentioned igneous rocks are intruded
by a series of intermediate and basic
dykes, whose age has not been deter-
mined. Regarding the evidence for
the geological age of these New
England plutonic rocks, the " Acid
Granite" and the " Sphene-Granite
Porphyry " both intrude the Lower a
Marine Series (Permo-Carboniferous), |
while the former also intrudes the a
X'-^vX
158
latter ; both also intrude the " Blue Granite," which, however, is
not known to intrude any Permo-Carboniferous strata ; none of
these plutonic rocks intrude the Triassic strata, which occur in
the eastern part of this region. Taking these facts in con-
junction with what has been said about the crustal movements
which affected this region in late Palaeozoic times (Chapter X),
it would seem probable that the ages given above are approxi-
mately correct.
Fig. 79.
Granite, Baker's Creek, New England.
Many extensive occurrences of Serpentine (altered Peridotite)
are found in New South Wales, whose age has not yet been
definitely determined. The most striking example occurs in New
England, and extends, as a narrow belt, from Bingera past
Barraba, Crow Mount, and Nundle, at intervals, to Port Mac-
quarie, a distance of about 200 miles. This intrudes strata of
Devonian age, but is not known to intrude any younger formation.
Other well-known examples occur at Lucknow, near Orange (an
altered Andesite), and at Gundagai. These serpentine occurrences
159
may be provisionally referred to the Kanimbla Epoch. The
occurrence of extensive intrusions of basic and ultrabasic
igneous rocks which do not outcrop at the surface is implied by
the occurrence of fragments of gabbro and peridotite in the
dykes and volcanic necks of the Sydney-Blue Mountain and
Illawarra districts. These have evidently been brought upward
from some deep-seated source by the material which filled these
dykes and necks.
(6) Cainozoic Intrusive Rocks. — Extensive epeirogenic move-
ments affected the earth's crust in Eastern Australia during this
era, and these have been accompanied in places by those types of
intrusion which are usually associated with such movements,
viz., laccolites, sills, dykes, and necks (plugs). These i.itrude the
Trias-Jura strata ; but as no younger sedimentary strata exist
where these intrusions are found, the exact determination of
their age is difficult. They include a highly interesting series
of alkaline rocks which, in their composition, appear to be
related to the lavas of late Tertiary age described on page 163.
This series includes nepheline-syenites, tinguaites, trachytes,
and bostonites. In the neighbourhood of Lue, several large
laccolites of tinguaite intrude the Triassic strata of that region.
The rocks here consist of soda-orthoclase, nepheline, segirine, and
sodalite, and are very rich in soda ; they are prevailingly green in
colour, and make a handsome ornamental stone when polished.
In the Mittagong-Bowral district numerous dykes and (?) plugs
of alkaline trachyte occur ; the latter will be referred to again on
page 164.
In the Kiama district, sills of Nepheline-Syenite and Tinguaite
intrude the Upper Coal Measures (Permo-Carboniferous) ; their
age has not been determined, but their composition suggests that
they are allied to the Tertiary alkaline rocks of other localities.
The analyses are given in Table II of some of these interesting
alkaline rocks, which, as will be seen, contain from 10 to 16 per
cent, of alkalies, with very low percentages of the alkaline earths.
As stated above, they are very similar in composition to the
alkaline lavas described on page 163, but as to whether the
two series were intruded and ejected contemporaneously it is at
present impossible to say.
An interesting series of basic intrusions also occurs in the
eastern part of New South Wales ; these have been studied in
some detail in the Sydney Blue Mountain area, where they occur
in the form of dykes, sills, plugs, and small laccolites. For such
basic rocks they contain a high percentage of alkalies, as will be
seen from the analyses in Table III.
One of the most interesting of these intrusions is that which
occurs at Prospect, near Parramatta ; it is a (?) sill of peculiar
160
shape containing analcite-dolerite, and intrudes the Wianamatta
Shales. Interesting aplitic and pegmatitic segregation veins are
found near the periphery of this intrusion, the former of which
are markedly more acidic and alkaline than the parent rock, and
consist mainly of al bite-felspar and analcite. Of the many
volcanic necks which occur in this region, some are filled,
wholly or partly, with basalt ; and such were probably points
of eruption. There are others, however, which are filled with a
breccia, composed largely of non-igneous material, including
fragments of coal, carbonaceous shale, sandstone, <fec., derived
from the wall rocks ; of such are those occurring at Hornsby,
Springwood, Euroka Farm, and The Basin (Nepean River).
These more or less cylindrical apertures have probably been
produced by the action of steam and other gases imprisoned in
magma reservoirs at no great distance below the surface, and
which have, by their explosive energy, drilled an opening upwards
through the overlying strata until escape became possible ; they
possessed, however, neither energy enough to clear the vent of
the comminuted rock material produced in forcing their way
upwards, nor to force the molten magma to the surface. The
volcanic neck at Dundas, near Parramatta, which is filled partly
with basalt and partly with agglomerate, contains numerous
fragments (xenoliths) of basic and ultrabasic plutonic rocks
embedded in the basalt ; these include gabbros and peridotites,.
with a considerable variety of mineral composition. Similar
xenoliths have been found in basic dykes as far south as Kiama,
and as far west as Bowenfels ; their occurrence may be taken to
indicate that large basic and ultrabasic plutonic intrusions occur
beneath this area, but are too deep-seated to have been revealed
anywhere at the surface by denudation.
Basic dykes occur in considerable numbers in the districts
adjacent to Sydney ; those which outcrop along the coast while
having a general east and west strike appear to have a radial
arrangement, and to converge to a locus about 20 miles due
east of Botany Bay. They range from a few inches up to 20
feet and upwards in thickness. Similar dykes in the Illawarra
district intersect the Upper Coal Measures, and have, in the case
of the larger ones, done considerable damage to the coal seams.
Here also basic sills have intruded the same strata, in some
cases (North Bulli) along the top of the Bulli seam, in other cases
(Metropolitan Colliery) along the middle of the seam for long
distances; such sills destroy the! coal over large areas.
B. THE VOLCANIC ROCKS.
No active volcanoes occur in New South Wales, nor in any
other part of Australia, at the present day ; nevertheless there is
abundant evidence to show that vulcanism had frequently, and
161
for long periods of time, been an important factor in its geological
history. Nearly every period belonging to the Palaeozoic Era
had its active volcanoes, from which extensive floods of lava were
poured out. The Mesozoic Era, on the other hand, appears to
have been quite free from volcanic displays. In the Caiiiozoic Era
renewed activity took place ; first came great floods of basaltic
lava from fissure eruptions, while later on volcanic cones developed
as the result of the piling up of alkaline lavas and tuffs. These
late Tertiary cones, although they have suffered considerable
denudation, still remain as evidence of the great eruptions which
produced them. Reference has already been made in previous
chapters to the volcanic rocks associated with the strata of each of
the geological periods. These occurrences will now be summarised
in chronological order.
Nothing is yet known regarding the vulcanicity of pre-Palseozoic
times ; some of the pre-Cambrian rocks of the Barrier district
may represent metamorphosed lavas and tuffs, but no detailed
description of these rocks is yet available. The volcanic erup-
tions of the Palaeozoic Era appear, in most cases, to have occurred
in, or adjacent to, subsidence areas, and to have, in the main, pre-
ceded the more important crustal movements. The Carboniferous
eruptions, for example, appear to have been confined to the north-
eastern part of the State, the only part undergoing subsidence at
that period.
Cambrian Period. — Nothing is yet known of the vulcanicity,
if any, of this period.
Ordovician Period. — Extensive deposits of andesitic lavas and
tuffs occur, associated with the Ordovician strata of the Orange—
Cadia district. These volcanic rocks have a great thickness at
Forest Reefs, near Orange, and the tuffs there are crowned with
angular fragments up to a foot or more in diameter. Andesitic
lavas of Ordovician age have also been described from the Forbes-
Parkes district. No analyses of these rocks are available.
Silurian Period. — Considerable volcanic activity took place
during this period ; rhyolite lavas and tuffs occur interstratified
with Silurian strata at Jenolan Caves, at Bo wen Park, near Orange,
in the Yass district, and on the Hargraves gold-field ; while
andesitic lavas and tuffs occur in the Parkes-Forbes districts.
The published information regarding these occurrences, however,
is very scanty. Many of the rhy elites of this and the next period
closely resemble quartz-porphyry in the hand specimens, and are
frequently mistaken for this intrusive rock.
Devonian Period. — The Silurian vulcanism continued on into
the Devonian Period, at the beginning of which stupendous out-
pourings of acid lavas and tuffs took place in south-eastern New
3910— P
162
»South Wales and north-eastern Victoria. At Taemas, in the for-
mer State, these accumulated to a maximum thickness of 5,000
feet, while, in addition, the thick Lower Devonian marine strata,
which overlie them, are more or less tuffaceous throughout. In
the Tarn worth district, also, vulcanicity was a pronounced feature
during this epoch. During the Upper Devonian Epoch, on the
other hand, vulcanism was, except in the Yalwal district, more
or less dormant ; in this locality, however, an extensive alter-
nating series of rhyolite and basalt flows of some magnitude was
poured out.
Carboniferous. — Volcanic eruptions, although confined to the
north-eastern part of the State, occurred there on a grand scale
throughout the greater part of this period, but particularly
towards its close. In the Paterson and Clarence Town districts
at least twelve distinct lava flows, as well as thick beds of volcanic
ash, are interstratified with the Carboniferous strata (see Fig. 25);
these lava flows, which range up to 200 feet or more in thickness,
are nearly all acidic in composition (rhyolites), but some hypers-
thene-andesitcs are also said to occur. Extensive deposits of
Carboniferous rhyolites and tuffs also occur on the Drake gold-
field, in northern New England, and in the neighbourhood of
Bolivia and Tenterfield.
Per mo-Carboniferous. — During this period vulcanism was, on
the whole, less pronounced and more local in its distribution than
had been the case in the Carboniferous Period. During the early
part of the Lower Marine Epoch, several extensive basic and
intermediate lava-flows were poured out in what is now the
Hunter River district, while at about the same time an extensive
series of andesitic lavas and tuffs accumulated in northern New
England (Drake gold-field). Then followed a considerable period
of rest until, towards the close of the Upper Marine Epoch, a great
•centre of eruption developed in the Illawarra district. Submarine
volcanoes here poured out a great series of lavas and tuffs on a
subsiding sea-floor; these range up to 1,000 feet in thickness, and
vary from basic to intermediate in com position, and have already
been described in some detail on page 72. These eruptions
continued on into the Upper Coal Measure Epoch, but on
a much reduced scale, when two small basalt flows were
poured out into the Coal Measure swamps. At this time a
new centre of eruption developed near Murrurundi, on the
north-western margin of the coal-basin, from which basaltic
lavas, aggregating many hundreds feet in thickness, were
poured out.
The Mesozoic Era. — No volcanic eruptions are definitely known
to have occurred in New South Wales during this era. Certain
beda of chocolate-coloured shales, which belong to the Narrabeen
163
stage of the Hawkesbury Series (Triassic), are considered to be
redistributed tuffs, and have the following composition : —
SiO2
A1208
Fc2(V
FeO
MgO
CaO
Na20
K30
H20
62-92%
2330
0-27
3-80
0-66
0-58
0-28
1-52
7-00
As to whether these were produced by Triassic volcanic eruptions
is not known ; in any case they were formed very early in the
Mesozoic era. No other volcanic rocks of Mesozoic age are defi-
nitely known to occur in New South Wales.
Cainozoic Era. — The long period of rest which characterised
the Mesozoic Era now gave place to renewed volcanic activity.
This resulted in the outpouring of vast floods of basaltic lavas,
which filled and in many places overflowed the river channels,
and thus buried hundreds of square miles of country under a
-covering of basalt. These sheets of basalt still form the surface
rocks over large areas in New South Wales. There are reasons
for thinking, as explained in the previous chapter, that these
Tertiary basalts belong to two distinct periods of eruption — an
older basalt series now represented by cappings on the tops of
more or less isolated hills (residuals), which rise above the general
level of the tablelands, and a younger series which over large
areas forms the surface capping of the tableland itself. The
former have been provisionally assigned to the Eocene Period,
the latter to the Upper Miocene or Lower Pliocene Period.
These olivene-basalts (see analyses), from a petrological point of
view, possess no feature of special interest, but by their
weathering they have produced some of the finest agricultural
soils in the State. Towards the close of the Pliocene Period
several isolated centres of eruption developed, from which a
highly interesting series of alkaline lavas was erupted. These
lavas and their associated tuffs built up groups of volcanic cones,
such as the Canobolas Mountains, near Orange, the Warrumbungle
Mountains, near Coonabarabran, and the Nandewar Mountains,
near Inverell. Taking the first-named as a type, they stand on
the top of the tableland, near Orange, adjacent to a fault (or
series of faults) marking its western edge. The first eruptions
brought to the surface a series of highly acid and alkaline viscous
lavas, which built up a series of steep lava cones ; then came
great showers of volcanic ash, included in which were fragments
varying up to several tons in weight. Further lava-flows followed
at intervals, becoming progressively more basic, the eruptions
finally closing with the outpouring of somewhat basic alkaline
andesites. The order of extrusion of lavas was as follows : —
1. Alkaline Rhyolites (Comendites) and Quartz Trachytes.
2. Alkaline Trachytes.
3. Phonolitic Trachytes.
4. Andesites.
164
The Warrumbungle and Nandewar Mountains consist of similar
lavas and tuffs, as may be seen from the analyses in Table V.
In the Mittagong-Bowral district two large cones of alkaline lava
occur, viz., the Gib Rock and Mount Jellore. The well-known
Gib rises about 1,000 feet above the surrounding country, and
consists of a fine-grained alkaline syenite (allied to bostonite),
which consists mainly of orthoclase-felspar, and contains narrow
segregation veins consisting of sanidine, hornblende, and aegirine.
This rock makes an excellent building stone, and is used to a
considerable extent in the buildings of Sydney. The Gib is
believed to represent the denuded plug of a volcano similar to
those occurring in the Warrumbungle Mountains. Mount Jellore
is a similar lava cone, consisting of alkaline trachyte.
Alkaline trachytes also occur near Dubbo, and at various
places in the Northern Rivers district.
Summarising the igneous rocks of New South Wales from the
point of view of composition and age, we get the following : —
Volcanic. Intrusive.
Cambrian ...
Ordovician ...
Silurian
Devonian ... . . P
Carboniferous
Permo-Carboniferous
Triassic
Jurassic
Cretaceous ...
Eocene
Miocene
Lower Pliocene
Upper Pliocene
None known.
Intermediate.
Acidic to interme-
diate.
Acidic (mainly).
Acidic (mainly).
Intermediate to
basic.
V Absent.
1
Basic.
Acidic to basic and
highly alkaline.
None known.
Intermediate.
Acidic to interme-
diate.
Acidic mainly.
Absent.
Basic.
Acidic to basic and
highly alkaline.
The true age of the alkaline igneous rocks is still uncertain,
but on physiographical grounds the volcanic members appear to
belong to late Tertiary.
It will be seen that the earlier Palaeozoic igneous rocks, as far
as we know them, were intermediate in composition \ then
followed a long period of time, during which the igneous rocks
intruded and extruded were dominantly acidic in composition,
while the final Palaeozoic extrusives were intermediate to basic in
composition. The Tertiary igneous rocks were dominantly basic
in composition, with a closing but limited phase of a highly
alkaline acidic to basic series.
165
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INDEX.
Acacia, 151.
Acentrophorus, 114, 115.
Acidaspis, 32.
Acid Granite, the, 156, 157.
Actinoceras, 22, 32.
Actinocrinus, 57.
Actinocystis, 40.
^llalong, 112.
Aetheolepis, 114.
Agnostus, 16.
Agrosaurus, 127.
Alethopteris, 90, 92, 93, 113, 117, 120.
Alkaline Lavas, 137, 139, 146, 163, 164.
Allandale, 62.
Alnus, 139.
Alveolites, 40.
Anbonychia, 11.
Ammonites, 126, 127, 128.
Amphibia, fossils, 112, 114, 115.
Amphibolite, 8, 9.
Amplexus, 57.
Ancyloceras, 126.
Andesite, 15, 16, 18, 43, 55, 62, 139,
163, 164.
Aneimites, 56.
Annularia, 90.
Anodontopis, 32.
Anoplotheca, 32.
Apateolepis, 114, 115.
Aphanaia, 86, 88.
Aphnelepis, 114.
Arachnophyllum, 25, 29, 32.
Araucarites, 113, 120.
Archaeocidaris, 86.
Archaeocyathinse, 11, 12.
Archaeomene, 114.
Archaeopteris, 47, 48, 56.
Archaeozoic Era, 4.
Artesian Series, 4, 104, 118, 120.
Artesian Water, 118.
Arumpo, 130.
Ashford, 53, 66.
Ashford Coal Basin, 65.
Astartila, 72, 86.
Astylospongia, 31.
Athyris, 48, 57.
Atrypa, 22, 30, 32, 40, 48.
Aucella, 126, 127.
Auckland, County of, 14, 46.
Aviculopecten, 48, 57, 62, 69, 86.
B
Bacchus Marsh, 97.
Baiera, 90, 92, 93, 113, 120.
Bald Hills, 134, 138.
Balmain Colliery, 83.
Banksia, 139.
Barraba, 38, 55, 137.
Barrier District, 4, 8, 10, 156.
Basalt, 47, 62, 74, 75, 84, 134, 137, 163.
Bathurst District, 24, 134, 138, 156.
Bathurst Lead. 132, 134, 138.
Belemnites, 126, 127, 128.
Belonorliyncus, 114.
Belenostomus, 127.
Bellerophon, 32, 40, 48, 57.
Berridale, 4, 15.
Beyrichia, 114.
Bingera, 38.
Black-soil Plains, 7.
Blue Granite, The, 156, 157.
Blue Mountain Tableland, 6, 43, 83,
104, 107, 111, 138, 159.
Boambola, 22.
Bombax, 139.
Borenore, 25.
Bothriceps, 90, 93.
Bowning, 20, 21.
Bowral, 6, 164.
Brachyphyllum, 83, 90.
Braidwood, 35, 37.
Branxton, Stage, 67, 68.
Broken Bago, 104.
Broken Hill, 4, 8.
Bronteus, 31, 32.
Buchan and Bindi Beds, 36, 37.
Bulyeroi, Bore 123.
Bundanoon, 69.
Buttai Beds, 76.
Cadia, 4, 15, 16.
Cainozoic Era, 3, 130.
,, Intrusive Igneous Rocks, 159.
,, Volcanic ,, 163.
Calamites, 56.
Calymene, 32.
Caraarotcechia, 32.
Cambewarra Mountain, 72, 73, 75, 84.
Cambrian Life, 11.
172
Cambrian Period, 4, 10.
Camden Haven, 104.
Canobolas Mountains, 44, 137, 139, 163.
Canowindra, 44.
Capertee, 35, 48, 68, 95.
Campbelltown, 111.
Campophyllum, 40, 57.
Carboniferous, Life, 56.
Lower, 53.
Period, 4, 53.
Plants, 92.
Upper, 53, 54.
Volcanic Rocks, 161.
Carbonicola, 86.
Carcoar, 16.
Cardiopteris, 56.
Cardita, 130.
Cavan, 36.
Central Tableland, 5, 6, 138.
Cerithium, 130.
Cessnock, 66.
Cheirurus, 32.
Chelodina, 140.
Chocolate Shales, 106.
Chcenomya, 72, 86.
Beds, 67.
Choetetes, 32.
Chonetes, 36, 40, 41, 48, 57.
Climliosaurus, 127.
Cinnamonmm, 139.
Clarence Series, 4, 104, 116, 120.
Clarence Town, 54, 55.
Cleithrolepis, 114, 115, 116.
Cleobis, 86, 88.
Clifton, 84.
Climacograptus, 16.
Clyde River Beds, 67, 70, 71.
Coal, Analyses of, 94.
,, Estimate of Amount Available,
66, 94.
Origin of, 79.
Measures, East Maitland, 61, 75,
76.
Greta, 63, 66.
Lower, 4, 61, 63.
Middle, 61, 75, 76.
Tomago, 61, 75, 76.
Upper, 4, 61, 76.
Cobar, 26, 45.
Coccolepis, 114.
Comendite, 139, 163, 164.
Conocardium* 32.
Conocephalites, 11.
Conularia, 69, 72, 86.
Gooma District, 4, 8, 9, 15, 137, 154.
Coonamble, 118.
Cordaitcs, 47, 48, 92.
Corimya, 126.
Coscinocyathus, 11.
Crasatella, 130.
Cremorne Bore, 106.
Cretaceous Life, 125.
Lower, 4, 123.
Peneplain, 138, 144.
Period, 4, 123, 146.
Crinoidal Stage, 67, 68.
Crioceras, 126, 127, 128. .
Cristellaria, 126.
Cromus, 32.
Crowe Mountain, 55.
Cryptograptus, 16.
Cucullsea, 126, 130.
Cullen Bullen, 83.
Cupriferous Shales, 106.
Curlewis Coal Field, 81.
Cyathophyllum, 22, 26, 32, 39, 40, 43,
57.
Cycadopteris, 113.
Cylonema, 30, 32.
Cyclostigma, 56.
Cyphaspis, 32.
Cyrenopsis, 126.
Cyrtina, 32, 57.
Cystiphyllum, 40.
Cytheridse, 114.
Dadoxylon, 66, 71, 83, 90, 91, 92.
Darwinula, 114.
De Gray Ranges, 125.
Deltopecten, 72, 86.
Dempsey Series, 4, 61, 75, 76.
Dentalium, 40.
Desert Sandstone Formation, 4, 123,
124, 125.
Devonian, Flora, 49.
Lower, 4, 35, 37.
Period, 4, 34.
Upper, 4, 35, 37, 43.
Volcanic Rocks, 161.
Diatomaceous Earth Deposits, 137.
Analyses of, 137.
Dicellograptus, 16.
Dicotyledonous, Leaves, 139.
Dicranograptus, 16.
Didymograptus, 16.
Dielasma, 72, 86.
Dingo, 142.
Diphyphyllum, 39, 40.
Diplograptus, 16.
Diprotodon, 140, 141, 142, 151.
Discina, 126.
173
Discorbina, 113.
Dolichometopus, 11.
Drake, 55, 63, 64, 117.
Dromornis, 140, 143.
Dubbo, 118, 164.
Echidna, 140, 143.
Edmondia, 57, 63, 86.
Elonichthys, 114.
Elpisopholis, 114, 115.
Emmaville District, 63, 139.
Encrinurus, 23, 31, 32.
Endothyra, 86, 113.
Entolium, 57.
Etomis, 86.
Eocene, Strata, 130.
Equisetum, 113, 114, 120.
Estheria, 114, 115.
Shales, 106.
Eucalyptus, 139, 151.
Euomphalus, 32, 48, 57.
Eurydesma, 62, 86, 88.
F
Fagus, 139.
Farley, Stage, 61, 62.
Favosites, 22, 23, 26, 32, 40, 43, 47.
Fenestella, 29, 30, 32, 47, 57, 62, 69,
71, 86, 87.
Fish, Fossil, 41, 44, 48, 93, 112, 114,
119, 127.
Fluviatile Deposits, 132.
Forbes, 16, 26, 44, 135.
Forest Reefs, 132, 137, 139.
Four-mile Creek Beds, 76.
Ganorhyncus, 40, 41.
Gangainopteris, 63, 66, 90, 91, 97.
Gap Creek, Orange District, 44, 45, 46.
Genoa Creek Beds, 37, 47.
Genyornis, 143.
Gerringong, 71, 74.
Ginkgo, 113, 120.
Glacial Beds, Cambrian, 10.
,, ,, Permo- Carboniferous, 61.
„ Epoch, The, 151.
,, Erratics, 68.
Glaciation, Cambrian, 10.
Cause of, 98.
,, Permo-Carboniferous, 96,97.
Pleistocene, 151.
Glaucomene, 32.
Glossograptus, 16.
Glossopteris, 66, 76, 78, 80, 81, 83, 90,9 K
Glycimeris, 126.
Gomphoceras, 32.
Gondwana Land, 98.
Goniatites, 63, 69, 72, 86, 89.
Gosford, 114.
Gosfordia, 114.
Graf ton, 116.
Graptolites, 16.
Great Eastraliaii Peneplain, 138, 144.
Greta Coal Measures, 63, 66.
Grevillia, 139.
Griffithides, 57.
Gulgong, 69, 114, 132, 136, 139.
Gunnedah, 81, 83, 107.
Gunnedah Coalfield, 81.
Gunning, 139.
Guy Fawkes, 6, 131.
Guyra, 6.
Gympie Beds, 53, 54.
Halmaturus, 140, 142.
Halysites, 25, 26, 27, 29, 32, 40.
Hamites, 126.
Haploceras, 126.
Haplophragmiurn, 113, 126.
Hargraves, 24, 25, 43.
Harper's Hill, Sandstones, 61, 62.
Harpes, 32.
Hartley, 156.
Hartley Vale, 83, 95.
Hausmannia, 26, 31, 32.
Hawkesbury Sandstone, 4, 81, 104, 106,.
107, 110, 111, 114.
Heliolites, 22, 23, 26, 32, 40, 43, 47.
Heliophyllum, 27, 32.
Highlands of New South Wales, 5.
Hill End, 25.
Hunter River District, 61, 63, 67, 75,
76, 121, 154.
Hyalostelia, 11, 86.
Hyolithes, 11, 16, 32, 72,86.
Ichthyopterygia, 126.
Ichthyosaurus, 126, 127.
Igneous Rocks, 155.
Illawarra Coal-field, 84.
District, 67, 69, 84, 95, 160.
lllrenus, 32.
174
Inman Valley, S.A., 97.
Inoceramus, 126, 127.
Insects, Fossil, 90.
Isocrinus, 126.
Jamberoo, 72, 75, 84.
Jenolan, 4, 22, 24.
Joadja, 95.
Jurassic Period, 103.
Kangaroo, 140, 142, 151.
Kanimbla, 51, 52, 155.
Valley, 156.
Katoomba, 83, 95.
Keeneia, 62, 89.
Kerosene Shale, 66, 81, 83, 84, 95.
„ ,, Origin of, 95.
Kiandra Lead, 132, 138.
Kiama District, 71, 72, 75.
Kosciusko Epoch, 146, 148.
Tableland, 9, 151, 152.
Kurrajong, 111.
Labyrinthodonts, 112, 114.
Lagena, 86, 126.
Lambiaii Series, 35, 43.
Lamna, 127.
Largs, 153, 154.
Laurus, 139.
Leads, Bathurst, 134.
Deep, 132.
Forest Reefs, 137.
Gulgong, 136.
Kiandra, 132, 138.
,, Lower Tertiary, 132.
Parkes-Forbes, 135.
„ Shallow, 132.
Upper Tertiary, 134.
Vegetable Creek, 134.
Leperditia, 11.
Lepidodendron, 37, 38, 39, 42, 43, 44,
45, 47, 48, 49, 53, 54, 56.
Leptsena, 26, 48, 57, 58.
Leptodomus, 48.
Leptolepis, 114.
Lichas, 32.
Lightning Ridge, 125.
Lima, 126
Lignite Beds. 134.
Lingula, 32, 43, 44, 48, 72, 86, 126.
Lithgow Coal Measures, 83.
District, 68, 83, 104.
Litophyllum, 40.
Lituola, 86.
Lobb's Hole, 37.
Lochinvar .Anticline, 65.
Stage, 61, 62.
Lophophyllum, 57.
Lower Coal Measures, 4, 63.
,, Marine Series, 4, 61.
Loxonema. 30, 32, 41, 48, 57.
Lowther, 156.
Lyndhurst Goldfield, 15.
Maccoyella, 126, 127.
Macropus, 140, 142.
Macrotseniopteris, 113, 114, 118, 120.
Magnolia, 139.
Mammals, Placental, 140.
Mandurama, 4, 15.
Marine Series, Lower, 4, 61.
Upper, 4, 61.
Marsupials, 140.
Martiniopsis, 69, 72, 86, 87.
Mastodonsaurus, 114, 115.
Megalania, 140.
Meiolania, 140.
Melosira, 137.
Merismoptera, 72, 86.
Meristina, 32.
Mesozoic, Era, 4, 103.
Mesozoic, Volcanic Rocks, 162.
Metablastus, 57.
Metamorphic Series, 4, 8, 155.
Michelinia, 57.
Micraster, 126.
Microdiscus, 11.
Mictocystis, 25.
Milparinka, 124, 125.
Milton, 71.
Mindarie, 130.
Miocene Period, 132.
Mittagong, 83, 84, 95, 114, 164.
Modiola, 126.
Mceonia, 69, 71, 72, 86.
Molong-Canobolas Beds, 44.
Molong District, 4, 35.
Monaro Tableland, 5, 6.
Moree, 118, 123.
„ Bore, 119.
175
Mount Boppy, 26.
Brown, 125.
Drysdale, 26.
Hope, 26.
Kembla, 84, 95.
King George, 111.
Lambie, 4, 35, 40.
Oxley, 125.
Piddington, 114.
Tomah, 111.
View, 62.
Victoria, 107.
Mourlonia, 32. 72.
Mucophyllum, 26, 27, 29, 32.
Mudgee District, 43.
Murchisonia, 30, 32, 40, 41, 48, 72.
Muree Stage, 67, 68.
Murrumbidgee Beds, 4, 35, 39.
Murrurundi District, 81, 95, 107.
Muswellbrook, 66.
Myriolepis, 114.
Mytilus, 126.
N
Nandewar Mountains, 139, 164, 165.
Narrabeen, 106, 107, 114.
Beds, 4, 106, 107.
Stage, 81, 104.
Narrabri, 118.
Narrungutta, Ranges, 46.
Natica, 126.
Nautilus, 126.
Necks, Volcanic, 160.
Nepheline Syenite, 159.
Neuropteris, 90.
Newcastle Coal Measures, 76.
District, 77, 104.
New England Tableland, 5, 53, 54, 55,
66, 118, 135, 138, 156.
Newer Basalts, 137, 138, 146.
Nodosaria, 86, 126.
Noggerathiopsis, 66, 83, 90, 91, 92.
Northern Coalfield, 67.
,, Rivers District, 63.
Tableland, 5.
Notochelone, 127.
Notomya, 72, 86.
Nototherium, 140, 142, 151.
Nowra, 71.
Grits, 71.
Nubecularia, 62, 86, 1 13.
Nucula, 126.
Nuculana, 72.
Nymagee, 26.
Nyngan, 118.
Oakey Creek, 25.
Obolella, 11, 16.
Oleandridium, 113, 114, 120.
Olenellus, 11, 12.
Older Basalts, 132, 137, 138, 146.
Omphalotrochus, 32.
Ophileta, 11.
Orange District, 4, 6, 25.
Ordovician Period, 4, 12.
Volcanic Rocks, 161.
Oriostoma, 30, 32.
Ornithorhyncus, 140, 143.
Orthis, 11, 32, 45, 57, 58.
Orthisina, 11.
Orthoceras, 22, 24, 30, 32, 40, 41, 57,
72, 86, 89.
Orthotetes, 26, 32, 57.
Ostrea. 126.
Pachypora, 32.
Pakeoniscus, 114, 115, 116.
Palaeozoic Era, 4.
,, Intrusive Igneous Rocks,
155.
Palsester, 32, 86, 87.
Palechinus, 32.
Parubula, 37, 47.
Parkes, 16, 26, 44, 135.
Paterson, 55.
Pecten, 126.
Pecopteris, 47, 48.
Peneplain, Cretaceous, 144.
,, Great Eastralian, 144.
Pentacrinus, 126.
Pentamerus, 22, 23, 26, 30, 32.
Penteune, 139.
Periechocrinus, 57.
Permo-Carboniferous, Glaciatioii, 96.
Life, 85.
Period, 4, 60, 85.
Plants, 90, 92.
Volcanic Rocks,
162.
Petraia, 32.
Phacops, 22, 26, 31, 32.
Phascolonus, 140.
Phascolomys, 140, 142.
Phialocrinus, 71, 86, 87.
Phillipsastrea, 24, 27, 29, 32.
Phillipsia, 57.
Pholidophorus, 114, 115.
Phyllograptus, 16.
Phyllotheca, 90, 91, 92, 113, 114, 1201
176
Physical Geography of New South
Wales, 5.
Picton, 11.
Pisocrinus, 32.
Pittosporum, 139.
Placental Mammals, 140.
Platyceps, 114.
Platypus, 140.
Platyceras, 11.
Platyschisma, 69, 72, 89.
Platysomus, 114, 115.
Pleistocene Period, 3, 146r 149.
Plesiocapparis, 139.
Plesiosaurus, 127.
Pleuracanthus, 114, 115.
Pleurophorus, 86.
Pleurotomaria, 40.
Podozamites, 113, 119, 120.
Pokolbin, 53, 55, 86.
Polycope, 86.
Polymorphina, 126.
Polypora, 57, 62, 71, 85, 86, 87.
Port Kembla, |72.
,, Macquarie, 55.
,, Stephens, 55.
Portland, 83.
Pre-Cambrian Formations, 8.
Period, 4.
Prismatic Sandstone, 110, 111.
Pristisomus, 114.
Productus, 57, 58, 69, 72, 86, 87.
Prostus, 32.
Prospect, 159.
Proterozoic Era, 4.
Protoretepora, 71, 86.
Protospongia, 16.
Pseudavicula, 126.
Pterinea, 45, 48.
Pteronites, 47, 48, 57.
Ptychoparia, 11.
Ptycomphalina, 72.
Purisiphonia, 126.
Quercus, 139.
Radiolaria, 16, 28, 38.
Deposits, 22, 37.
,, Limestone, 15, 38.
Rathluba Beds, 76.
Ravensfield Sandstone, 61, 62.
Ravens worth, 81.
Raymond Terrace, 63, 64.
Receptaculites, 31, 39, 40.
Retiolites, 16.
Rhacopteris, 53, 56.
Beds, 4.
Rheophax, 126.
Rhizophyllum, 29,' 32.
Rhynchonella, 32, 40, 43, 44, 45, 47, 48,
57, 126.
Rhyolite, 22, 25, 36, 43, 47, 55, 81, 163.
Rhypidomella, 57, 58.
River Systems of New South Wales, 7.
River ina Plains, 7.
Rix's Creek Coalfield, 81.
Rolling-Downs Formation, 4, 123.
Saddle Reefs, 25.
Sagenodus, 114.
Salterella, 11.
Sanidophyllum, 40.
Sarcophilus, 140, 142.
Sauropterygia, 126.
Scaphites, 126.
Schizoneura, 90, 91, 92, 93, 97, 113, 114,
120.
Schizophoria, 57.
Semionotus, 114, 115.
Serpentine, 38, 158.
Serpula, 126.
Silurian Life, 28.
Period, 4, 19.
,, Volcanic Rocks, 161.
Southern Coal-field, 84.
South Western Coal-field, 69, 83.
Sphene Granite Porphyry, The, 156,
157.
Sphenopteris, 47, 48, 66, 81, 83, 90, 92,
113, 120.
! Spirifer, 22, 32, 36, 40, 41, 43, 44, 47, 48,
57, 58, 69, 71, 72, 85, 86, 87.
Spiriferina, 72, 86.
Spongilla, 137, 140.
Spondylostrobus, 139.
Spoiigophyllum, 32, 40.
Springwood, 111.
Staurocephalus, 32.
Stenopora, 62, 69, 71, 85, 86, 87.
Stenopteris, 113.
Stenotheca, 11.
Stockyard Mountain, 75.
St. Peters, 112, 114, 115.
Striatopora, 32.
Stromatopora, 23, 26, 28, 31, 39, 48.
Strophalosia, 57, 68, 69, 87.
Strophomena, 32.
177
Stutchburia, 72, 86.
Sydney, 104, 106, 107.
Sydney Harbour Colliery, 84.
Syringopora, 22, 32, 39, 40, 43, 47.
Tamiopteris, 113, 114, 117, 118, 119.
Talbragar, 83, 119.
Beds, 4, 104, 114, 119, 120.
Tallawang, 69.
Tallong, 4, 15, 18, 69, 83, 84.
Tamworth Beds, 4, 15, 37.
District, 15, 39.
Tangorin, Parish of, 66.
Tareena, 130.
Tarrawingie, 10.
Tasmanian Devil, 140, 142.
Tiger, 140, 142.
Tellina, 126.
Tentaculites, 32.
Terebratula, 126.
Tertiary, Fauna, 140.
Flora, 139.
Intrusive Igneous Rocks, 159.
Lower, 3, 132, 146, 147.
Period, 130, 146.
Upper, 3, 146, 147.
Volcanic Rocks, 163.
Thainniscus, 32.
Thinnfeldia, 113, 118, 119, 120.
Thylacinus, 140, 142.
Thylacoleo, 140, 142, 143.
Tibbooburra, 125.
Tinguaite, 159.
Tolwong, 15.
Tomago Coal Measures, 4, 75.
Tomingley, 4, 14, 16.
Topography of New South Wales, 143.
Trachypora, 85, 86.
Trachyte, 73, 75, 139, 163, 164.
Triassic Plants, 92.
„ Period, 4, 103.
Trias-Jura Period, 4, 103.
Tribrachiocrinus, 71, 86.
Trigonia, 126, 127, 130.
Trilobites, 11, 12, 16, 31, 32, 48, 57, 59,
90.
Trochus, 32.
Tryplasma, 22, 26, 27, 32.
Ulladulla, 71.
Unio, 109, 113, 140.
Unionella, 113.
Upper Cretaceous Formation, 4.
Coal Measures, 4, 76.
„ Devonian, 43.
„ Marine Series, 4, 67.
Urosthenes, 90, 93.
Vegetable Creek District, 139.
,, Leads, 134.
Vertebraria, 83, 90, 91.
Volcanic Necks, 160.
W
Walgett, 125.
Wallaby, 140, 142, 151.
Wallerawang, 83.
Wallon Bore, 123.
Wandra-Wandrian Sandstones, 71.
Warialda, 118.
Warrumbungle Mountains, 137, 139, 164
Wellesley, County of, 14.
Wellington, 4, 44.
Westley Park, 73.
Tuffs, 74.
West Maitland, 66.
Western Coal-field, 68, 83.
Western Plains, 5, 6.
White Cliffs, 124, 125.
Wianamatta Shales, 4, 111.
Stage, 104, 111, 114.
Wingen, 66.
Wilson's Downfall, 67.
Wolgan, 95.
Wolumla Gold-field, 46.
Wombat, 140, 142, 151.
Wombeyan, 24.
Woolgoolga, 116.
Wollongong, 71.
Wyralla, 137.
Yalwal Beds, 35, 47.
Yambulla Ranges, 44.
Yandama Station, 124.
Yarrangobilly, 24.
Yass District, 4, 20, 21.
„ Tableland, 6, 144, 145.
„ Canberra Tableland, 6, 144, 145.
Zaphrentis, 26, 32, 40, 57, 85, 86.
3910-G
Sydney : William Applegatc Gullick, Government Printer. —1811.
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