W. M. Dunkle The Geology of Western Cape Cod 1940 \ } } ! i ! 1} 2 . i h €b96E00 ToED g ON 1OHM my eg a ae : ™= ~ PO af S. 9 4% We or ran) ‘ 4 @ al Surve b ic J i n Can aS n PRO i ort 1 ig? ” Publi Geolog IC Ss: Hf Ge erio te LOG ‘e S shard, = e r. y t y Tt. é oe Ny chuse C A & 835 r artment : Sc Ba oA a An > ep the > in. SURVEY: Si a ws ha Te he ye £ EI T¥ 2 fiz m ICLY. aA M i tis D: ae rel lo ‘Geo SPS r¢ PER mr rs SO eo tad 2B THe Sc Sat ae > P h sac W. M. Dunkle Commonwealth of Massachusetts U. S. Department of the Interior Department of Public Works Geological Survey H. A. MacDonald, Commissioner W. Cs. Mendenhall, Director BULLETIN NO. 2 A PRELIMINARY REPORT ON THS GEOLOGY OF WESTERN CAPE COD, MASSACHUSETTS by Kirtley F. Mather, Richard P. Goldthwait Lincoln R.. 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Geslozic = Figure 1. Sketch map of scout quadranzies stud ips ~) l- a > Sketch rev oF xox areas coverei Dy Sketch man show = re = SOULNSASTSCIN nsEF a a 2 > ages = Sketches o2 wind-c as of Cazce rounded cobb! zrooves " rae Ee Szetcn mes of vart dreiras2= west of ia wr }4e Colctrwait and Thiesmeyer of the quadrangles studied astern Massachusetts showing svheasvern North America showing ieistocene Ice Sheets moraines and outwash plains of Seon and Long Island Sap ut stones from glacial deposits ies bevelled by wind-cut facets i ventizacts formed by intersecting ard furrows on boulder mgular yventifact rounded by later abrasion on granite boulder 2 grooves and pits ofiles across the Mashpee pitted plain in gravel oF Pocasset quadrangle showin the Buzzards Bay moraine ie SO a A PRELIMINARY REPORT ON THE GSOLOGY OF WESTERN CAPE COD, MASSACHUSETTS by Kirtley F. Mather, Richard FP. Goldthwait Lincoln R. Thiesmeyer Introduction Geolocists attempting to decipher the record of glacial times have long been interested in the features of Cape Cod and its neigh- toring islands. Technical reportsl/of their conclusions form an im- ly 4 selected group of these papers is listed at the end of this re- port Reference to them will be made by numbers in parentheses in- Ge their position in the alphabetical list. D ° ficating = portant part of geological literature. In recent years, through rap- id development of the Cape as a vacationland,the opening of numerous Dp roadcuts and excavations has made available hundreds of expo- Sy es of. subsurface materials that these investigators could not e seen. Storms, especially the hurricane of 1938, have cut back the cliffs at many places and stripped away slumped material that formerly obscured the geologic featurese Excellent new topographic maps of southeastern Massachusetts are being made by the United ctates Geological Survey in cooperation with the Department af Public “orks of the Commorwealthe Because the scale of these maps is larger and their contour interval is smaller, they provide a more accurate tase upon which to plot the geologic features than did the maps used by previous investigators. Techniques in studying and interpreting ° u ~ recent years, geologists have been reporting an even greater com- lexity of glacial devosits in New Sngland than had been previously rferred. It seemed advisable, therefore, to undertake a systematic e-examination of the geolosy in this critical and classic area. The field work that forms the basis of this report was done during the summer of 1939,as 9 part of a continuing project for geo- 1 locic mapping under the cooperative auspices of the Massachusetts ~#partment of Public Works, and the Geological Survey, United States ~epartmert of the Interior. This report is designed to present to the intellisert lay reader in non-technical language the si the origin and development or iendforms and scenery of the aregga mapped thus far hese incluce the rewly-mapped Sagamore, Pocasset, Sandwich and Falmouth quadranzies, most of the Woods Hole quadrangle: and parts of the Onset and Meromet quadrangles. (Fig. 1). This acaz count embodies what is thouzrt to te the best interpretation, inthe light of modern geologic soncents, of all the facts known and ine ferred from study of these areas up to the’ present time. nical discussions are planzed for later publication. Remapping of Cape Cod ng zeoiozy is continuing during the year Similar reports will extend this story into adjacent quad-; r texéed that within a few vears the citizens i] ° anglese Thus it is intex fe ot a3 The Table of Geologic Time mg! The history of any region prior to events observed by man is pieced together from records left by processes of nature in its geo- logic formations and landforms. No single area contains a complete record since earliest geologic time. At a place like the Grand Can- yon in Arizona there are exposed vast thicknesses of rock layers that lie like a pile of manuscript pages, carrying the story of mil- lions of years of earth history. Yet even here there are gaps in the records; pages are missing from the manuscript, because at some early date erosion gnawed at the top of the pile for a time and car- ried off whole chapters before later ones were written. Such inter- ludes may be more fully recorded ina different locality, however, ard diligent search is necessary to complete the chronicle. Where sediments were laid down in layers and were not later overturned by some great earth movement, it follows that the sequence of the layers gives the sequence of events or- conditions in their ‘formation. It is possible, too, that layers in one part of an area were contemporaneous with those in another as,for-example, the wind- blowvm sards of “the Cape Cod dunes are contemporaneous with the beaches and bottom muds. now forming in Buzzards Bay. Periodically throughout the past the continuous flow of time has been.. punctuated by widespread- upheavals of the earth. These caused interruptions in depositional processes and made possible the recocrition of.-the units of geologic time, listed in what is known as the table of geolozic time’. It encompasses more than a billion years. (See Table 1). Its longer subdivisions are known as eras. They consist of périods which, in turn, may be separated into epochs. Numerous smaller-divisions are discovered as geologic studies con- tinue to unravel the complicated story of the earth's past. In contrast to the Grand Canyon, Cape Cod has .long been known to corsist of only a relatively thin veneer of sediments formed in this part of the. world during a very short: and much more recenti/ 1/ Note that this use of the word, recent, is not the same as its techrical use in the time-table. In this report it will be capital- ized wnerever the restricted time interval of the table is intended. episods, so that they are not yet consolidated into rock and may, indeed, be carried away by wave and stream erosion before consolida- tion can occure Firmly consolidated rocks are not exposed anywhere on the Cape, but are believed .to lie several hundred feet below the surface rear Woods Hole, and may be nearly a thousand feet below at Provincetowne This report, therefore, is concerned with only the upper more recent part of the geologists! time-table, comprising tut a fraction of the last million years of world history. Consequently all of the earlier, lower.part of the accompanying time-table has been simplified and abbreviated, icdite Tables tt. The Table of Geolosic Time CENOZOIC ERA -=- duration about 60 million years ‘PRE (Recent epoch -- since the last SlnGiers of. the Ice Age bate eee disappeared from New Englands;estimated | _ * as 20,000 to 30,000 years durationsmay be only erator interglacial staze of tthe Pleistocene. ; Pleistocene epoch -- The Great Ice ‘Age or glacial epoch == duration about a million yearsSe | *4th glacial’ stage (Wisconsin glaciation) ; Quaternary duration 50, 000+ yearse period cher Oke stage (aeation interslacial ‘time ) ; duration 100,000+ yearse | 3rd glacial stace Gane glaciation) ; duration 50, 000+ years. | Interglacial stage Ceanonen interglacial time) duration 500,000+ years, énd glacial stage (cncee elaciation) | . duration 50, 000+ yearse | | \ ~ each may be further sub- divided: into sub-stages. -Interglacial stage (leconiaa interglacial time) duration 200, Q00+ years. ic Ist glacial staze cae glaciation) duration 50, 000+ years. : j Tertiary period -- the Age of Mammals” MeSOZOIC ERA** -- the Age of Reptiles -- dinosaurs,etc.,first birds; - euEee eon about 150 million years. PALSOZOIC ERA** -- first appearance . of nearly all the major groups of plants and fa acs aa quseesen about 400 million ‘-Years-e RE-PALEOZOIC ERAS ** —- beginnings of plant and animal lifesnumerous ‘divisions; probably corstitute the major parts of geologic time3 dura™ion at least a billion vearSe : *Some geologists subdivide this into two stages of glaciation, known-as the Early Wisconsin (or Iowan) stage and the.Late Wis- .cornsin Sta ES. ; ‘ **These eras, like the Cenozoic, are also ‘subdivided into nu- merous periods, but inasmuch 4s formations belonging to these periods are not exposed anywhere on Cape Cod, they are not listed in this table. 4 3 # 4 3 Sy 4 4 | | ce h America 4 wo joe 3 4 3 ct Recause most of Cape Cod ard its neighboring areas are made up of deposits formed ty giaciers of tre Ice Age and their meltwaters, it is appropriate to corsicer briefly the origin and spread of these mighty ice sheets. Discussion of the causes of glacial climate is, however, beyond the scope of this report. This picture of the growth and exparsion of glaciers is tased partly on our knowledge of the behavior of glacial ice wherever it exists today, and partly on in- ferences drawn from deposits telieved to be of glacial origin now found over broad tracts in tre rmorthern hemispheree he the close of the Tertiary period, rm olimatic conditions throughout i) i : pies a ter 2 a interval of rather ec rat at th vous the averaze was everywhere lowered a few de- EBYeeSe This initiate colder, moister weather which de- veloped into an ice Az weich fell during the winters at high altitudes and in rors es was not completely removed by summer melting. The excess oF nm year accumulated on top of that of the preceding year. racked -down by the weight of snow heaped upon it, and altered in its structure by partial melting and refreezing, this snow turned to ices The ice began to spread outward or move sluggishly downhill, under the weight of increasing accumulations of snow, just as do modern giaciers in the Alps or in the Rockies today. After thousands of years,the ice had piled up to such thickness that large areas of land were biar eed by far-flung sheets of ice like those which cover Greenlard and Antarctica today. These Fleistocere zlaciers, like their modern counterparts, were thickest where the ee egos n of snow had been heaviest, and be- came thimer progressively outward. Several such masses, shaped like inverted saucer 3 3 Je i i7)) ard covering a total of many millions of square er Q miles,formed in northern 4trerica,Zurope, and Asia and reached thick- nesses estimated as " erest BS eee feet at their centerss At the same time the Greenland and Artarctic ice fields were thicker and thousands of square miles broader under the cold Pleistocene climate than they are todaye - it sroule be noted that there were several separate ice caps, only two of which had their centers in the polar recions, Many peopie have = see caken impression that the ice of the polar areas simply expazced ard moved into temperate latitudes during the Ice Age, and that it has shrunk since then to its present dimen- Siors » These j outward in all directions in some re- spects ured ona table. Their margins moved over the irre ee and extended far into warmer lati- tudes. + oniy so long as the forward movement co ee be melted or evaporated away i oy @ 5 Ze} cr each d azes of thick ice behind them, the ad- var.cin up over hills and even in some places to cov N ruge gathering-grounds of Pleistocene ice: one over northeastern Quebec and Labrador,one over the Keewatin area west of Hudson Bay, and a third over the northern Rockies of Canada. Within a few tens of thousands of years, ice masses that had developed in these areas spread out to coalesce, interfinger or overlap one with the other, (Fige a The southern margin of th compound ice sheet reached Long Island on the east, Ste Louis in the certral interior, and the Canadian border on’ the northwest where the motion was impeded somewhat by the rugged peaks of the western moun- tain rangese Motion of the Ice Sheets The rates at which different parts of the ice crept over the land varie considerably from place to place and from time- to time. We have no way of measuring the precise speed of advance exceot by comparison with the motion of modern glaciers, but it seems safe to conclude that it could ‘generally have been measured in yards per month rather than in-miles.— Obstructions, slope of the ground, earthquakes, weather conditions, and amount of * snow in the centers where its accumulation was greatest were important influences. In part the movement was probably like the slow,steady, viscous: flow of a thick syrup, and.in part a sort of interrupted, staccato skidding. Naturally the ice would move more rapidly along valleys and would be protected from melting in them longer than it was on adja- cent uplands and divides. Consequently the rims of the expanding glaciers. became very irregular in outline. Large volumes of ice moved into major topographic depressions like theSt. Lawrence valley lowland inthe form of lobes that stretched far in advance of the ‘main body of icée Some of these lobes were large enough to spread laterally while they advaneed, whereas thinner “ones. were confined within valley walls. During later melting and recession of the ice borders, these lobate shapes became even more pronouncede Effect of Glaciation on Life ‘As the zone of more rigorous climati¢é .conditions surrounding these glaciers © moved outward, animals and plarits unable to cope with the pee 1sing environment perished, unaware ‘that the remote glaciers were aling thém a lethal blow. Other animals and plants sensitive to Stich chanses migrated far in advance of the oncoming ice, or retaired their habitat for awhile by adapting themselves ‘to the new conditions. There was no sudden evacuation, however, because the chanzes were very gradual, almost imperceptible toan individual seneration. Nevertheless, even the hardier creatures finally yielded to. the relentless onslaught of savage, biting winds that blew down ade the ice and spread their chill influence for hundreds ofmiles ad-of the ice front. Some of these rorthern creatures took up oe in Florida. At the same time, the hairy ancestors of modm. man were huddling and shivering in the caves of southern France.» The land close to the ice was, however, not barren by any meanse Rugged plants and arctic animals thrived in the vicinity of a glacier or spread over its thin margins just laske. But they were immigrants Glacial Deposits While the ice was accumulating in low areas and valleys, clocks of rock loosened from valley walls by strozg frost action rattled down and landed on its surface. Torrermts of reinneter washed great quantities of soil and stones onto it. Strong cold winds blew dust geross .its surface and it became dirty ice, mich like thet which develops some time after a snowstorm even today. This material was then covered with more ice and the process revestec.- At the base of the ice or along the side walls underneeth, loose soil, boulders,and blocks of rock were frozen into the srowing gieciers As it moved, already charged with rock debris, it scraped still more material from the floor and sides, and plucked. huce 21 om surfaces over Which it rode. Soils in front of it o ds ul to be overridden and incorporated, i : Pp ’ jumbled fragments in the lower part or oOo i) ab pet Le terial thus carried in the ice as it by derived from it,was destined to be dep nds the process or when the ice melted. in ots oc: or boulders that must have travelled their Source. During the advance, the glacially-transvori ents acted as abrasives to scrape and polish bedrock lean and widen the bottoms of valleys, or scratch s lel grooves on rock floors such as may be seen at th es throughout New Englend. In this way the debris-le and puiveruzed much of the materials over which it roc thet iv was car- ryinge Many fragments that escaped crushin ided, polished, and scratched by the smaller particles led among them or were dragged against sharp projecting s oz: hardsr rocks locked an, the icy grip of the glaciers ‘ | All along the irregular front of @ = a@ jumbled mass of rock materials was piled to forma belt that now extends i s ss the countryside and marks the uneven i CYANCE « t of it may have been shoved along like material in front of a plow,and part of it was merely dumped where it now ilies es the ice border nelitede Geologists call such a deposit of ice-borre nsterials a moraine. 4A moraine may range from a few yards to several miles in widths and its hisher parts may rise a hundred feet cr more above its sur- roundingse At some places it may. stand om isvel ¢ 3 Grewse— € where it may.rise along the slopes of Hil jAocation determined by the position of time of depositione Where the .moraine is rather wide Simultaneously, of course, Materiel later with similar material by s1i pushed forward to new positions. 2h forth within a few miles, probably for centuries, each local advance bringing a fresh supply of debris. Masses of dirty ice became iso- lated and buried among the rock materials. When they finally melted and contributed their load to the moraine, the material above them slumped down and irregular hollows were formed on the surface. Such pits are known as kettles or kettle-holes. The surface of any mar- ginal moraine is generally rough, partly because of the great number of such. kettles and partly because of the irregular hummocks or knobs between them that result from abrupt variations in the thick- ress of the debris. The. geologist: gives ene name till to such a heterogeneous ac- cumulation of unlayered (unstratified) material. Till usually con- sists of fragments of many. sizes, from great blocks of rock to pul- verized rock flour. .:This material was either dumped, or pushed a- head of, or plastered beneath a glacier. Till was also spread as a ‘thin veneer over the land behind the outermost, terminal moraine either because. it was laid there by the .overriding ice during its advance or because it was-let down slowly upon the surface when the glacier meltede The name ground moraine is applied to such bodies of till. scattered over the area covered by the ice, The thickness of a deposit of till may vary a great deal. In some places whole hills are made of till, whereas nearby areas are free from any such cover- INS. : . : . . ; 2 ~ Blocks and.boulders carried by the ice were deposited at random “over the glaciated tract. Those transported far from their source are composed of rock material that may be quite different fromthe bedrock. underlying their present resting-place. Some rest in the midst of till masses or on top of them, and others are now. perched atop naked rock ledgese Such ice-carried blocks are called erratics. Even while the . ice-sheets were increasing in size, varts of then melted during the day time and during the: summer months, esne- ‘cially those portions that. had reached low altitudes and warmer re- gions. The meltwaters were loaded with rock debris, and they depos- ited it in layers in front of the ices Such material, ‘known as out- wash, consists of. gravel, sand, and silt mixed with small amounts of clave As it was transported partly by ice and partly by water, it may be called. glacio-fluvial debris. The particles in it became rounded and smoother than the more angular fragments generally found in glacial +i01) because they were rolled and jarred against one an- other during water trarsporte ; { Some melting also occurred during the. construction of the inoraine so that masses of stratified outwash sands and gravels are occasionally found embedded in the till of the moraine. Small streams of meltwater piled canelike masses of outwash in front of the ice and resting against ite Sand and gravel also ac -cumulated in hollows on the surface of the icee. When the glacier molted away from these masses, they stood as isolated hills known as kamesS in places a whole series of them were built along the ice front so that they form an almost continuous, irregular ridge. Outwash also ac- cumulated in broad, low, fan-shaped masses extending outward from the ice for several milese Because of their gentle surface slope, such features are called outwash plains. Deposits of all sorts fomaed by glaciers or their meltwaters -constitute what is known as glacial drift. (A land surface that has been glaciated is thus veneered d with an irregular mantle of-drift, «which includes moraines, outwash plains, kames and erratics, as well ‘as other types of-glacial, ‘glacio-lacustrine and glecio-fluvial de- posits that. need not be mentioned here, inasmuch es they are not re- presented in the area under consideration. The drift at any one plece may, ‘therefore, consist of either till or glacio-fluvial ma- “terials or both; and at some ‘places~: the drift may include Geposits formed-during several ‘successive stages of glaciation. : _ . Retreat of the Glaciers ‘Whenever the climate of the Pleistocene became warmer or drier, he margins. of thé melting glaciers’ ‘receded, even though the ice composing them may have continued to move. forward. This retreat was induced not. only by more rapid’melting and evaporation of the ice, which caused.a thinning and down-wasting of its border regions ,but also by a reduced supnly because of smaller accumulations of snow at the center. The glacier fronts receded, gradually uncovering the land and spreading vast quantities of outwash over ithere and there. lekes were formed where drainage was’ blocked by glacial deposits as weil as in hollows. on the irregular surface of the drift. Plants-and animals reropulated the glaciated terrains, following closely behind the . dwindling ice and‘spreading across the rocky, glacier-borne soils. : US wee The ice recession was by no meang continuous. There were spells of cooler weather within centuries: of warmer conditions so’ that the gleciers pushed forward again for short distances,plowing and piling “up debris.they had previously dumped’on the land, At times the ice ~front stood at almost the same position for scores of ‘years because only as much new ice was pushed forward each year as was melted. Consequently, moraines were heaped up to mark places where the ice front pane cred practically stationary,. just as they had marked the ‘limit of maximum advance. Because this process was repeated fre- quently during the thousands of years of recession, a great ‘series of these recessional moraines was strimg across the countryside In the central United States where: the lands are relatively flet, Pree e are easy to recognize ; but in the-moumtainous comtry of the eastern areas. and in.most of New England, no such extensive systems of mo- »rainic belts have been observed. - Several Episodes of Glaciation . Geologists who studies the glacial deposits of North America and hurope during the latter part of the last century and the first part of this were soon convinced. that.during Pleistocene time the ice Sheets formed and spread, melted and Sioa speared several times, -and that the climate of the world was. even warmer during some of the intervals between flacial episodes than it is today, They subdivided the Pleistocene, therefore, into stages of See eal advance and interslacial stages, each lasting ten is hundreds of thousands of yearse (See Tabl z ca there were at least four distinct ¢l PHPth, each marked by depos- its such as iedine paragraphs.» The ar ial stage are not identical. Ge as! poss fe) iH terminal moraines of each stage and. t dep rlier Pleistocene glaciations that were not overridden ty later Pleistocene glaciers. Fortunately the tills ofearlier stazes were not everywhere plowed up and removed during readvance of the ice. ae at some places we can find tre sediments of saverei stazes lying one above another, proving that these localities were sucjected to repeated glaciation. It would not-be easy to distixnzuish the several tills, however, if the older ones were not more rotted and stained because they lay exposed to weathering for a longer time. Here and there, layers of soil con- tefining the-remains of plants that could thrive only in warm weather have teen found tetween till layers. This is clear evidence that af- ter the ice that laid the lower and, therefore, older material had disappeared, vegetation Zlourisned for a while and was then buried when glaciation prevailed once more. lacial-reaterizls is thinner in the eastern 2 certral statese Although the thickvess of 3s zererally only a few feet, in placés it of New Eneland over which a did not yield so large 2 S 11 over the gas ach hundreds of ce had to travel s more r ume of crushed and pulveri a hy (Up Sy $ ie iw) t ~ a ct Fst a) 3 bh Q 140) a a bir j iq) @ Q n O77 p pat] OV n Tr nity country of the Rorenenee r-southe Perhaps, therefore, he -ctearing ice moving across a a thousand years of each glacial stages Pos- c influerce oF the reighboring ocean in some way thick as it was farther west; as tter over the land surfaces s is exposed.in the maritime rocks had been weathered so zl hem during millions of years the Ice Agee ane: ol ed from these soils during any stage of glaciation cold not, therefore, be uniform in color from place to piace + is an uncertain procedure to New Englard til early Pleistocene, simply be- ks badly rotte tures a thy Oo yD > Me | oO | a greater variety of rock ty than in the inlard states oils of mary colors devel ie there was less decris k n eo Be ce oO Lae e Hy fa 7) b ie peek ic)) S na ia) a by pad f oo ° 6 2 ciation ineastern North America ard study as have those in the zy is much obscured by glacial finitely, therefore, how man} 1 ~ ey ba! vo | t' oO 3D ch -¢ck & yo i" oO 7p) Pleistocene time, nor can e of glaciation be precisely ae he } easvern 1am1 were wmcovere Other complications in the glecial =z are attributable to its hilly topograpry. during ice recessions earlier than were 6 Tong, narrow masses of ice stood stagnent in separated from the receding margin o- shrank, their meltwaters were ponded 4 walls. lakebed sands and silts which these temporary basins conceal whatever fluvial materials may have been spread turies of ice recession, New England mu till-veneered or barren hills alternsting with stagnant ice massc and dotted with ephemeral lakes. mu Change of Sealevel A significant fact to keep in mind concerning the Ice Age is that. the sealevel of the whole world stcod i150 to more than 200 feet lower than it does today. The glaciers were fed by snow that could only have come originally from evaporation of seawater. As the ice increased in thiclmess, the sealevel went i oh hore "i line migrated out from its previous position the interglacial stages enormous volwnes cf their waters to the ocean; the sealevel ro back over the continental margins, Sane the New Englend strandline may have mov of the present shore during the stages of ed $a Formation of Cave Cod ty Pleistocene Ice Sheets cre Deposits More than a century 2z0, Hitchcock (3) described the abundance of scattered erratic boulders strewn over Cape Cod and adjacert is- lards, and attributed them to "the flood" of biblical history, but not without some urncertaixcty as to the adequacy of that explanation. grized and proved that the Cape consists jacial and siacio-fluvial materials,and that its es ers morasmic “in origine They hee suggested re comcimiations of glacial features observed eres. ard parts of eastern Massachusetts. that these moraines a _ Long Isiand, eee ed tre question concerning the stage to s which shese deposits ozrz ty suggesting that "Martha's Vineyard ard parts of Cape Cod and the mainlard of Massachusetts were free of Ce ea. Ghe date Wiscozrsin arc perhaps even through the whole of Wis- consin time." Moreover, » Sayles (5), working principally on the more easterly portion of tne Cave, observed phenomena indicative of ial was disturbed by frost heaving ot | an even greater comolexity or zlacial’and associated deposits tha had been inferred \. Seg From intensive 2 areas mapped during the summer of 1939 and from. rec ps over the rest of the Cape, the ‘authors of this va y convinced that the major features of Cape cod geol during the later substages of the Wisconsin stage-of acion -cecause: 1. The till and associaved slacio o-fluvial gravels are, with few exceptions, rot as rard and compact as one would expect es to be had they been overridcer cy later ice or subjected for a long time to cementation by ground water and es ney are not as stained and rotted as the } ai 2. Ty 3 y should te if exposed to a long interval of weatheringe ch e = z ion oF piartv roots and the zone of weathered soil at tre top of the deposits are relatively thin, averaging tozether less thar 3 feet. Such thin zones could not represent a long inter- val of disturbance ard exposure to weathering. 3 Slopes producec ty rzelting of buried ice blocks have teen modified very little by siumpize ard rainwash, and the bottoms of kettles are almost free of surface fill which would have accumulated in them to considerable thicimesses had they stood open for more than a few ters of thousazds of yearse 4, Surface drainaze has made very little headway in gullying and modifying the coztours of the moraines and outwash plainse We would expect m =) i 1 loose materials in so long a time as that fron consin to the presente Deposits %} early Wisconsin or earlier Pleistocere stages = parts of southeastern Massa- chusetts, especially east and rorth of the areas included in this reporte These may ce seen in the lower parts of the cliffs on the north shore tetyveen Hllisville and Plymouth, north of Tennis, and from Chatrem to Truro. Details corcerning them must te deferred to aa Puture report after they have been mapped and studied in the con- uation of field work. | It is believed, furthermore, that the deposits’ ‘of western Cape Cod were formed during the waning and recession of the ice of the Wisconsin stage and that the moraines-are, therefore, recessional morainese The presence of hundreds ‘of kettle-holes, many of them now dccupied by ponds, that range up to a mile or more in length and width, throughout the south central part ‘of the Cape makes. this conclusion inescapable. They were formed because myriads ‘of ice= blocks isolated from the retreating glacier stood in those locali-~ ties, were covered by outwash and then melted away. Thus they show that considerable volumes of ice existed far south of the moraine fronts on the northern’part of the Capee The terminal’ moraine of the Wisconsin ice must have formed south of the moraines on Cape Cod,and is probably represented ‘by’ the morainic ridges of Martha's eee ard Nantucket, as described by Woodworth and fesclsone (7) and otherse ; hee ’ : ve at natn ss : ict al a ' Wisconsin Terminal Moraine in brief outline, the story of the formation of Cape Cod during the Pleistocene, based on corclusions from ‘this study and on those of earlier investigators, is as follows: (See Fig. 3). The ice of at least one earlier glacial episode’ of the Pleis- tocene” reached this region and «spread deposits which were modified and almost complete ly concealed by the advance of ‘later ice sheets. During Wisconsin time glacial ice extended’ southward from northern New England, moved over what is now the Cape’and reached a termiral position .on Nantucket, Martha's Vineyard, and Long Island. The margin of this ice sheet was_ pronouncedly lobates One lobe stretched southwestward down what is now the Buzzards Bay trough, and another spread southward across the floor of Cape Cod Bay which was tren dry land because ‘of the lowered sealevel. According to-J.B. Woodworth (7), a third lobe extended southeastward over the floor of what is row the eastern part of Massachusetts Bay and stood east ‘of Provincetown and Chathame The terminal moraine marking the maximum spread of this ice was built along a sinuous line loopéd from Nan- tucket to Martha's Vineyard to Block Island to Montauk Point at the east end of Long Islands A broad outwash plain was formed as 4 fringe alorg the south side of this ‘moraine. Later the lower parts of the moraine’ and much of the associated outwash deposits, bot north ahd south of it, were. drowned when the sealevel rose again, but the higher portion may be observed on these islands» Recéssional Moraines and Outwash Plains “The ice frort retreated many miles northward in response to changes in the climate and its lobate form doubtless became more marked. Masses of stagnant ice were left standing at many places in the uncoveréd areas Much of the record of the easternmost lobe has been obli terated by the rise of sealevel, but the other two lobes ae a ore réceded mary =i havior on western Cape Code Thei present morth shore of the case remained there long enough to the Mashpee pitted plein,- in a gently sloping fan with its the junction of the two lobese en aie: a 2 the northern and western edges of the pitted plain, a=4 remained theré long enough ‘to. pile the till of what is called herein the Buzzards Ray moraine and the ‘Sandwich moraire over the These moraines were.considered.as a single contiruots urtt ty Woodworth, which he’ called the "Falmouth moraine e" ror reasozs stated below, however, it is-helieved. that this slight readvance of the-two lobes was not simultaneous and that the ‘eastern arm of fiootrorctn's Salmouth moraine can be distinguished from the part that exterds southvestward paralleling Buzzards Raye The Buzzards Bay lore laid doxm its recessional moraine at ‘the edge of the pitted plain somewhat earlier than did the Cape Cod Ray lobe, so that the Sandvicn moraine Sane te and lies upon the northern end or the Buzzards Bay moraine rear the Cape Cod Canale _ After the Cspe_ Sod Sey ee had shrunk tack, spreading more wtwash in its wakes, north of Sandwich moraine, another ‘episode of colder or more rumid cond 's drove it forward again,:not so far as.tefrore, but far enouzh to deposit a smaller, narrower, less con- tinuous moraine, the Scorton moraine, upon this. later outwash. The Buzzards Bay lobe aprerertly left no easily-recognized record of ‘similar readvance, altnouch possitly sucha record lies concealed tereath the water of Suczards Bay or is represented by small patches of till on top of gravel tetween the moraine ard the Ray shores : Durirg a later epi ‘of retreat the ice front-of the Buzzards — s rorthvestward, perhaps as far as -Kingston t and South Duxbury tefore ited. The Cape Cod Bay lobe withdrew likewise northward into tre e then its southwestern margin pushed ‘forward again ard stood for a tong time ina zone extending northwest rrom the vicinity of Zilisville toward Plymouth. Here it tuilta third prominent recessioral ewe hich is called the Ellisville moraire for the présexus o . The Buzzards Bay loce had left enormous blocks of ice in what must have been a cortimious valley area close to the southvest mar- Zin of the Bllisville moraize. These are now marked by the deep, elongate depressiors tzat contain Great Herring Poni, Little Herring .Pornd, Sloody Ford, anc long Fond in the Sagamore quadrangle. © These tloéks were covered my a compound fan of outwash gravels ard sands poured out sonthwestwerd from the Cape Cod Ray lore simultaneously with its construction of the #llisville moraine. Thus the blocks ace : Swash plain, the Wareham pitted plain, was melted avay to form ee kettle-holes -tiorship of the Warekam pitted plain to i is different from ae relationship its bordering mornAinese The south-= moraine is irregular and difficult the Wareham pitted plain slope up - 15 = to. cover portions of it and extend into it in places Such an ir- regular overlapping and interfingering of deposits is Aoroad or the relations between a moraine and an outwash plain that are built si- multaneously.e The story of the activity of these lobes as they drew back still farther to the north and west must te deferred until the quadrangles adjacent to those covered by the writers have been mappede The area of the Cape .east of the quadrangles that “have been mapped in detail is underlain in part ry. deposits continuous with those mentioned above. The Mashpee pitted plain extends into the Cotuit quadrangle, and the Sandwich moraine stretches eastward along the north shore of the Capes NE. Chute's recent study (2) substan- tiates the conclusions of earlier workers that anothér large pitted plain extends southwestward on the ‘southeastern end of the Cape and spreads toward. the Mashpee pitted plain. The eastern arm of the Cape from Chatham to Provincetown. may be in part an interlobate moraine | formed between the ‘Cape Cod ‘Bay lobe and the Massachusetts Fay lobe, | tut the complexities of its geology require careful study “before we can outline in any detail the story of Pleistocene conditions in that areae Wind-seculptured Stones (Ventifacts) | During both. the advance and the recession of the Wisconsin ice over the Cape Cod region strong winds blew down across its irregular surface and whirled up clouds of sand and silt on the outwash. plains and the exposed seafloor in front of the glacier. Sandstorms must have been frequent, and a current of wind- driven, sand must have been | moving close to the land surface almost constantly. Blocks and boul- | ders and even smaller stones that lay in the path of this sand-blast were worn and polished. Smooth, almost flat surfaces were tevelled across rounded rocks. (Fige 4a)e When these stones were dislodged and rolled into new positions, other parts of them were likewise bevelled. Some of the rounded cobbles became pyramid-shaped and sharply angular where one wind-cut facet intersected anothere ‘(Pige 4b). Even granite and quartzite pebbles; which are normally as hard as or harder than steel, were shaped by this incessant abrasion. Many of the wind-scoured stones have irregular pits and grooves or furrows where the sand stream etched out their less resistant partse uPig. 4c,¢e,f) Some stones lay exposed to such action for a long time, and they bear marked evidences of the wind-cutting; others were quickly covered or protected by falling into the lee of larger stones or by being shifted out of the wind-blast, and they show only the begin- nings of modification by sand-hlastinge Some of these stones, or course, never moved out of position before they were buried by sand or ty later till or outwashe They show wind-sculpturing, therefore, on but one side. Some were picked up after they had teen cut and were moved to a different location by streams of meltwater or by the advancing ice itself. Consequently, they now lie embedded in till or deep within the layers of outwash gravel. Turing this second transport, the smooth, eg: wind-polished surfaces became dull, the sharp edges were ronnded orf - 4d), and the evidences of wind- j wer yed by another type of abrasion, J > e commonly eidece destro i © T face of such stozes feeis harsh and gritty, like that of any stream-corne pebble,wrereas tre wind-smoothed surfaces that. have not been thus partially obliterated, heve a greasy feeling like talcum powders 7 Without particular 2ffort mearly 2500 of these wind-cut stones were collected from all over the area considered in this report, in the midst of urdisturted gravel layers, in slumped materials along the faces of cliffs, embecded in till of the moraines, or lying on he surface. Scores more were fourd:in similar materials in various other parts of the Cape. J.2. Yoodworth (6) reported occurrences of them in areas which have mot yet teen re-studied. Literally millions of such stones must lie in the glacio-fluvial gravels and tills of this region. Their distribution is, however,: very irregular and rardom. One gravel pit may yield hundreds of these stones although rearby pits reveal scarcely any,or ore layer in an exposure may con- sist of them almost emtirely whereas the rest of the layers contain NONE « Corsidering the conditions under which they were produced, GhHIS 2S, Of Course, = rprisi ? Nee. Shute (2), OWirs rk Bryan's i) plea ern of these wind Lai stones or 7 us, thought they were rmed at the surface by wind actioz and the rurned down into the ee ma- terials ty overturning of the upser few feet of soil during frost action. The authors do rot agree entirely with that conclusion, for a great xe obviously cut while the ice still stood r 2 s subsequent movements, and have ‘not T ic It seems likely that most of the wind-scu Ipturing moplisned tefore the ice blocks had melted to produce } - Cecause there is very little wind- tloyn sard in any of 7 They would have been nearly or quite filled with ‘san 3 -stood open when the wind was driving large amounts of sard across the surface of the ground. In their opirior, therefore, =anyr ofthe ventifacts which now lie in the thin zone of disturted material near the surface were already embedded in the upper part of till ard gravel deposits before the disturtarce-by frost _and other asencies ever cheseeles iele a aaa aaa Lies Recent Modification. by Erosion Development. of. Guliies Erosion of the glaciated territory by raimvesh and by wind wa in progress during the recession of the aes ewly- ~formed land surfaces were subzect to :-such attec 1ey were un- covered, or even while they were being bu: ae of the, ice. Wind action diminished after the ice getation. spread over the -Cape and prevented the sands of the twash plains, trom drifting about as they must have done while the ventifacts were un- dergoing, sculpture by sandblast. As the .climete became gradually warmer and the seasons. of. freezing weather grew snorter, the number of rainstorms each. year,,increased, and erosion by running water was more continuous. Many small gullies develened.as the run-off began to.cut down through-the .loose deposits. Fresext lines of generally. ) fe Q _ poor -drainage. were established, a. few swanny ereas were dreined, and the. landseapes which had come. into existence during the Pleistocene epoch were somewhat modified by Recent erosi Te Phe degree of such modification, -however, is so slight,cors 3 tnat such loose, un- consolidated materials are. subject to rapid ercsion, that the time that. has.- elapsed .since.. the retreat of the ice could.not have been very long. Marine Submergence and Srosion The rise of sevice that peaeed when the ice relted brought the Atlantic strandline slowly. back toward its sent ee, As the water rose,it finally. lapped against the. outermost moraine. The lower parts...of this were submerged, and wide stresches .of it were cut away by the pounding surf. The moraine beits on Nantucket and Mertha‘s :-Vineyard..are the only remnant -of that .remain above sealevel in the Cape Cod eree. Sp them,the sea formed Nantucket Sound and Vineyard Sounc é z siniler attack on the recessional Buzzards Bay moraine eo 6) boom The -Eliza- beth Islands represent, the higher ae of thi ine southwest of Woods :Hole, .and the steep cliffs of tili the: irregular shoreline in.this part of the Cape are “stil i wuidergoing violent..et- tack by weaves. . The eastern.arm of the Cane, facing the heavy storms {3 ' (a) ;, ai pre ES ? of the open ocean, . offers... little resistance to the onslaught .of northeasters. It-has -been cut. back at least a mile or. two-in the last, few thousand years,.(2a) and will secon nually narrower. Near Wellfleet only about a mile of land with ¢ topography -now Separates the. waters of Cape Cod Bay from th the open oceans Along.the . south shore, .the sea flooded th ends.of the..long furrows in the outwash plains,turned then y estuaries, and invaded large kettle-holes to form such as Waquoit Bay (Felmouth quadrangle). The irregulerity excellent harbors for small.craft is 2 drowning of the uneven,.glacial, landscape. = Ae . Beaches: ‘Sandbar's and Dunes_ Materials derived from erosion along the coast have been dis- tributed by waves and currents to produce fine beaches and sandbars, especially along the southern and. eastern sides of the Cape. Currents moving patallel to the coast along the south shore built bars across many of the bays,. improving them as harbors .for small boats by af- fording protection from the open waters of the Sounds, and -straight- ened the actual shoreline by thus reducing its irregularities. A similar process occurred on the north shore. in the vicinity of Well- fleet, Monomoy Point and. many other similar coastal features are sandbars piled even above the high-tide mark by the waves: and cur- rents. As each” new bar jutting out. from the.-coast is built,it protects certain parts of the coast from direct attack and causes further deposition of sand at some: places; . but it may also deflect currents and cause more vigorous erosion elsewhere. ©The broad hook on which Provincetown is located at, the tip. ofthe eastern arm of the Cape has been built up since the. ‘Ice: Age by sand arta le there from the cliffs. to the south. “Wherever the beaches are wide ences — expose - os Gene ies of loose sand to the sweep of the wind, dunes have been formed. The largest and most extensive of ‘these are, of course, those near. Prov- incetown and Barnstable, but along many stretches of the coast there are patches of windblown sand lying against the cliffs on the inner margin of the beaches. Changes in the Surface Zones~': The upper few feet of till and gravel deposits have been altered by several agencies since the retreat of the ice sheets, Frost has heaved and overturned some of the stones. .Roots: have penetrated be- tween them and shifted them. In. the. upper two or three. feet at any exposure, all signs of original layering in outwash materials have been destroyed. The topmost six inches toa foot generally. consists of. chocolate brown to black, sandy. soil, rich in plant remains. Be- neath this is a reddish-brown zone in which the subsurface materials have been stained with iron rust. that comes from decay of iron-bear- ing minerals in .the soil and is spread . by the. downward percolation of rain water through the ground. Generally the lower part of the rusty zone grades*downward into a lighter colored zone, of yellowish brown or'tan color. Thus, the bottom of this stained zone is very irregular, and its contact with unstained materials below is common- ly. rather indistinct. The rusty stain locally penetrates to deeper levels in more porous materials or along irregular cracks. Commonly it is hard to tell at any single roadcut or pit just how much of the upper disturbed and weathered material was churned up and altered in place, and how much material has been brought there and deposited as & ‘thin: top mantle by slope wash and creep from adjacent hills. Re=- .gardless of its origin, | however, the thinness of the zone of dis- turbed material corroborates the conclusion that not a great deal of time has elapsed sinte the ice disappeared from this region. Sees At many places, especially in areas covered by pine trees,there is a thin zone of white sand immediately beneath the surface of the sround, ranging from less than an inch to three or four-inches in thickmess.e This is a result of the removal of vegetal humus and iron oxides by a process of leaching that seems to be especially ef- fective under the conditions that obtain where pines are abundant. This bleached zone may be developed in the soil formed on till or glecio-fluvial materials alike, and its presence or absence is de- termiried by the chemical composition of “the rainwater seeping into the sround at the present time. This varies more from place to place because of the considerable differences in vegetation than because of the less significant differences in the mineral content. of the various kinds of glacial drift. Swamps and Bogs ry With the return of vegetation to this area,salt marshes devel- ‘oped close to the coast where sandbars had formed lagoons by enclos- ing embayments in the coastline, and the inland ponds-and swamps were densely populated with plants of many typés. These flourished and died, and new senerations grew upon one another repeatedly, so that salt-vater peat was formed in the lower cistricts and fresh- water peat in inland hollows. Many of the smaller ponds in kettle- holes have been completely. filled with peat accumulated during: the centuries of Recent time. In-places this mat of vesetal tissue is more than 12 feet. thick. During the hurricane of 1936 waves broke ecross sandbars at some localities and plunged into such peat accu~ mulations. Great mattresses of peat several feet thick were loosened, carried out on the receding waves, dashed to thousands of fragments by the surf, These. were then spread along the teaches for miles from their source. Along certain -short stretches of the coast, shoreline erosion has cut back through the material’ on cne side of a modern peat bog and is now removing the peat. Origin of the lariforms of Western Cape Cod ‘ashpee pitted plain More than 1CO scaugre miles of surface at the west end of Cape Cod. in the Pocasset, Falmouth, Sandwich, Cotuit and Hyannis quadran- gies,/ are underisin ty loose, stratified sand and gravel. This msa- eel es nemec only the Sandwich has been published istribution by the Geological Survey. terial is exposed in scores o: all pits excavated around cranberry bogs and along closely-spaced nie At many places the surface of the sand and gravel forms a nearly flat plain, as at the Massachu- setts National Guard Cemo, located in the southeastern corner of the Pocasset quadrangle (Plate II}. Other extensive portions of the sur- Pace are naturally pitted {as e pad farther on wider the heading “evidences of buried ice") and undulating. Long furrows also break the smoothness of the plain, and even its smoothest portions have a systematic gentile sicre toward the south or southeast. These fea- tures suggest a lors and complicated history. The name of the plain a8 Gerived ashpee. . Origzi this was a continuous, smooth plain without It is fan-shaped and the small end r apex formed where the Sandwich moraine rla 5 5 ine. The outer edge of the fan now ib = he waters of Nantucket and Vinevard he presext shoreline across this outer edge forms a broad rom Falmouth to Cotuit,. f an.-slopes gently ‘but regularly -from the alevel, south and east to the outer edge This surface slope is very slightly istinctly steeper near the apex of the Fig. 5). In the higher half of the the apex, the average slope is 15 to 20 ions formed near the apex at a later oO n 4 ne z Slope of deposition before pits were made ma e even greater.°. Indeed, some non-pitted portions of this upper part of the plein drop as much as 25 feet in one mile. The lower half of the plain, on the other hand, has a surface slope of only 12 to 15 feet ver mile where it is not pitted. DAP —- DAwe’ Origin of the Pisin ravel plain resemble closely those OS Such streams of meltwater ar with rock fragments from the ice. channels of the streams, forcing by streams that issue from beneath =.21 = their waters to divide and redivide into many smaller streams, each of whose channels also finally becomes clogged so that néw ones are continually teing formed. Such channels are cut during and just af- ter warm hours of the day when floods of meltwater issue from the ice. The channels become filled and blocked with debris during the receding of the waters at night or in cold periods when currents are less swift. Thus these manifold streams form a braided pattern con= stantly shifting over the plain. ~In this ways first one- and then another part of the broad plain | is built upe * Since the meltwater is’ often fed from one fixed outlet in the glacier, or from between the ice edge and a nearby: mountain wall,the deposit gradually assumes a fan shape radiating from that soyrce. The constructional surface of this fan slopes away from the apex. and tends to be concave, for the coarser materials near the apex build, to a steeper angle than the fine material washed toward the outer edge. ay 5 : a aes One would expect that the largest boulders, cobbles, or pebbles rolled by the periodic flcods would be transported the shortest dis- tances. They would-come to rest before sand would settle, ‘The dis- tribution of material in the Mashpee pitted plain bears’ -out this principle. The average size of the particles composing the: -plain ‘changes distinctly from that of well rounded gravel near the,epex to subangular sand at the outer margin. In the apex, rounded boulders 6 to 24 inches in diameter are scattered over the surface. “One pit in this apex located near the Pocasset Road, 1000 feet north of its intersection with Jefferson Road (Plate II), shows 4+to6 feet of very coarse gravel overlying 3 feet of cross-bedded sand with thin gravel lenses; a trench in:the Military Reservation north of Snake Pond ex- hibits coarse gravel. Many shallow rdéad cuts show the general pres- ence of gravel in this part of the plain. ‘On the other hand, expo- sures in the wave-cut cliffs of the outer, seaward edge of the plain consist almost exclusively of sand. Pits excavated for sand used in surfacing roads and bogs are scattered along State highway, Route 28, and around each cranberry bog in this vicinity. ‘Very little-.coarse gravel is available in these pits. oe There are exceptions to this gradation in coarseness, however. Most notable is a pit operated by the Lawrence Co. and located just west of Sols Pond, 1 miles northwest of Falmouth Heights. Although this-locality is only a mile anda half from the southern edge of the plain, it shows a 6-foot layer: of extremely coarse gravel con- taining rounded boulders up to 18 inches in diameter. On the floor of the pit are a few boulders as much as 30 inches. long. Similer coarse gravel with rounded cobbles 8 inches in diameter occurs:in a nearby pit just- southwest of Teaticket Village. The eastward dip or slope of the layers and of the surface between pits in this vicinity suggests that this .unusually coarse material was deposited by melt- water that issued from the’ adjacent Buzzards Bay lobe while the Buz- zards ‘Bay moraine was under construction.‘ Apparently streams from that source built a small local fan on top of the more extensive .and older deposits of the Mashpee pitted plain at this place. . "oe 22 - The leyering or bedding of the sand and gravel composing the plain resulted from alternate periods of flood :and slack water in the streams. Abrupt changes.in grain size distinguish adjacent lay- ers in all pitss;in places a coarse gravel bed. rests upon a fine sand bed, and vice versa.s The power of the currents which deposited thase beds was unusually variable. Even within a single bed of sand, cur- rent action has resulted’ in criss-cross patterns of. the fine layers lmown as cross~bedding. Groups of fine, light and dark, laminae of sand slope in many directions. © Such-cross—bedding was best exposed in 1939 ina pit along State highway, Route .22, at the head of Great Pond. In coarse gravel, the "scour and fill" nature of the deposit “is evident. Onthe southwest wall of the Lawrence Company pit re- ferred to above and in numerous gravel pits in-higher parts of the plain,. some of . the ease Havers orl broad SS ee like enseSe : ‘ eRe. OT Sie Setpttiee SRS arinitien| Saleataaat TTR All of the eiicker Henee whether they are extensive or not, are essentially, paraliel:.to the’ surface, of the.plain;.. none -is inclinsa steeply “forward ‘/in the direction of stream flow.. Such."foreset" structure would be indicative of a delta built by streams ina body of standing water, Lack of any such structure here, even in pits at the outermost edge of the exposed plain, indicates that this fan was built on land, and not to accord with any lake surface or sealevel. Eviderces of Buried Ice s The tremendous. natural pits in the plain .are most convincing evidence that this is glacial outwash. .These pits .occur chiefly in groups rear.Falmouth, Coonamessett, Massachusetts Natioral Guard Ri- fle Rangé, Forestdale, Farmersville, Newtown, the vicinity of Johns Pord, Waquoit, and Osterville. There is no system ‘or regularity to the grouping or tothe ‘positions of groups of pits in the plaine Hore than 30 pits exceed half a mile in length. They range in depth from 50 to 120 feet, and séveral. are enclosed completely by gravel walls to such depths. The most prominent examples are the depression which contains Snake Pond west of Forestdale and the hollows in the Massachusetts Guard Rifle Ranges near the -center of the Pocasset Mia quadrangle.* About 500 smaller pits: are shown as. depression contours on the rew EP oaoecaprse maps of the Geological Survey,and many others observed in the area under discussion are too small to show on maps of the scale used. The side slopes of the pits are inclined at an- gles ranging from 5 to) 202% Slopes around adjacent depression cen- ters’coalesce to form saddle-shiped ridgese The pits vary greatly in shapes; some are nearly circular, some elonzate ‘oval, and some quite irregular: Within an area of compound pits, the surface may resemble the hummocks and hollows of small "kame and kettle" depos- its so corion in the valleys throughout New England.’ These features -- the irregular grouping, the great depth, steep slopes, -and irrégular shape -- are prime characteristics of glacial kettle-holes, Such’ depressions were produced when masses of ice, seperated from the main’ .ice sheet, were surrounded and partially or completely covered by accumulating outwash gravel. Some years or Soon certuries later these ice blocks,melted sway, the protect er of gravel and sand collapsed into the holes wi } and the unconsolidated material barked egsi gradually slumped toward the bottoms of the action which produces long and narrow or wind action which makes a broad shallow tlowout, nor fr which subdues and fills deep holes is a satisfactory; explanation for pits with such shapé and ‘distribution. Furthernere, several of SEEM, such as those occupied by Long Pond and Cyster Fond near } or one lying southeast of Signal Hill in Sa ardvich,excernd fon yithnin the plain to within the bordering superficial glsci ‘these hollows ‘interrupt the continuous frort o ‘must have formed -after the moraine was ruilt on top of the mar of the outwash plain by readvancing ice. Clearly then these ‘are holes resulting from the melting of ice which had been bu a. the deposition of the plains One) Source of the Materials ac he: a) Two other conditions point to the fac of glacial outwash. The head of the plein more than 200 feet, which is far above any the recent past. River deposits at this a stream et this high levele Secondly, types known to oe out as solid. ledges rary plain. Pebbles of Sa tillite were and ina pit west of Coonamessett River, x 44 Carboniferous conglomerate .pebbles from the Basins were found at a dozen or more exposure ee those of the Boston region may calities The scarcity of these bs pas few piece that travelled 25-to 60 mile came mixed with far more abundant Bhone ss eties of rock like the Dedham ae whi part of every pebble count, probably came rock only a few miles away, although xo within 10 miles of the plain. i meee have travelled, the only plausible. soure are north ot west of Cape Cod. Southard by moving ite and its associated meltwater ence in the deposits described heree Marginal Area As already stated, the Buzzar are telts of glecial ia Reoate were leid on top of stream-weshed the pitted pla northern margins of like the-gravel of he. all respects » 24 = 50 to 100 feet lower than that of the plain. Presumably, this gravel is continuous with that of the plain. As may be seen along the west- ern side of the Buzzards Bay moraine, its surface beneath the till is not smooth like so much of the plain, however, and great angular blocks are embedded in- it here and theres Therefore, it is believed that these portions of the plain, now buried under the moraine, were originally the ‘marginal+portions of the great fan as it was con- structed during retreat of the ice before readvance produced the overlying moraines Such portions were’‘deposited on and around irreg- ular masses of ice at the ragged edge of the ice sheet. Shifting currents, such as would: result from movements of water over this rough and changing landscape, deposited layers sloping at unsystem- atic anzles. The irregularity of the surfacé increased as the buried ice melted. Angular blocks from the ice fell and slid onto the srav- el at some placese : Source of the Meltwaters The water which tuilt the pitted plain carried some fragments. of rock like those found in both the Sandwich moraine on the north and the Buzzards Bay moraine on the weste Counts of the number of different kinds of rocks among 200 pebbles selected at random at» each of 12 locations bear out this subjective observation made at innumerable pits (Table 2a). Only one stone count, that from a pit> west of Péters Pond in Forestdale near the pouchwesccrs corner of the Sandwich quadrangle, is closely Similar to counts in the Sandwich moraine, and only two stone counts, one made west of the Massachu- setts National Guard camp on Turpentine Road near the center of the Pocasset: quadrangle, the other almost half a mile east of Shallow Pond on-the north side of Mill Road in the northwestern part of the Falmouth quadrangle, are much like counts in ‘the Buzzards Bay mo- raine. The average of all pebble counts from the plain shows a pro- portion of granites, diorites, and basalts like that of the Buzzards Bay moraine, whereas the proportion of volcanic and quartzite peb- bles is like that of the Sandwich moraine. Because the proportions of several types of rock containéd in the two moraines are signifi- cantly different, as may’ be seen in Table 2b, itis concluded that the water “that bore gravel to the pitted plain: gathered. material from sources under both lobes of the ice sheet. - During transporta- tion these pebbles were fairly well commingledy The uniform slope of the plain to the south and southeast, away from the apex and in directions ‘parallel to each moraine front, shows that a -considerable part. of the water entered the plain somewhere near or at the present apex, rather than here and there along the line of the moraines, At two localities, one located half a mile southeast of Sigral Hill and about a mile northwest of the certer of the Pocasset quadrangle and the other just north of Falmouth near Grews Pond, the plain shows a marked slope away from’the bordering morainee. In the first of these ‘the'deposit is made of sand and is shaped like a small fane At the Falmouth locality it is made of coarse gravel already described in discussion of the Lawrence ’ - 25 - Company's pit. Presumably, water that flowed through breaks in the ridge on the east side of the Buzzards Bay moraine or directly from the face of the Buzzards Bay glacial lobe superimposed fans on top of the main plain at these two localities. Associated Older Gravels At two other places constructional gravel deposits rise above the general surface of the pitted plain. The most conspicuous one is Falmouth Heights on the shore of Vineyard Sound. The present shape of the deposit is elliptical, and its top is 35 feet above the adjacent plain. On the seaward side a 40-foot wave-cut cliff cone sists entirely of crossbedded sand and gravel. In the upper layers of the gravel are many ventifacts. This gravel must have been de- posited as outwash from the ice prior to the building of the pitted plain, for its altitude implies ice or other gravel immediately sur- rounding the present site to enable streams to deposit at sucha high level. This deposition occurred before any other event registered by the surface deposits on this end of Cape Cod. Presumably it oc- curred while the ice front was retreating from Martha's Vineyard to- ward the line of the Buzzards Bay and Sandwich moraines. Originally the deposit may have been far more extensive, If so,most of it must have been removed, in part by streams from the ice that was retreat- ing north and west of it long before the low outwash fan was built around it and in part by ocean waves which are now active at present sealevel. It is more than likely that this body of gravel never extended very much farther toward the north than it does today, and that it represents the apex of an outwash fan built southward from an ice front that was temporarily standing close by the Heights. Rather rapid recession of the ice then removed the support from the north Side of the fan, and subsequent outwash deposits were never built to so great an altitude. The other outwash deposit above the pitted plain is a discon- tinuous, broad, low ridge trending southeast from the edge of the Sandwich moraine north of the Cape Cod Airport into the plein as far as the Barnstable-Falmouth Road. At its northwest end, this ridge blends into the moraine front;at its southeast end it is half a mile south of the moraine. Its undulating crest rises 10 to 25 feet above the adjacent plain, and it consists of well-bedded and crossbedded sandy grevel without boulders. The gentle south slope and slightly steeper north side of the ridge suggest that it, too, was deposited by glacially-fed streams when the ice edge stood close to or along its northern margin. Till Clumps in Gravel Till is not ordinarily found in glacial outwash. Till comes di- rectly from ice; gravel is washed and sorted by the meltwater. Ir- regular clumps of till were found, however, in excavations at six localities in the Mashpee pitted plain in the midst of gravel far Toss ag, ist ‘ Pt sy Oe 4s Sag Ose tet eh apn Se CaIAIINACINA ay br o> fe oc an | 1G satus, gta wo Ait bed . ‘ 0 Oo | G0 1-66 % 0° 0 Othe ae ang TLYUAWOTONOO : tins 9 050: 0°°0' Te 0 5, > SNOLSGNVS PHB gSoMEY $9 ho | 6 6.8 84k heheh el eee |. gman NITA 6 g*h BG sce Oe ley de ag | SLIZLuvad ‘ er aa (O9TTTTS28 Sutpntour) @ Mg Cot oot fe ee es aLYIS ms 2 mo f " (ouoqsuo0s9 SutTpnt out) $°% $ : OE BOP eae Be Get ISIHOS : ; : hee sof (potqgsetoosdd ¢ : ‘ > Haas pus egttofys ATQe80) IT $°ST % Geo 2 Te et do OT 6 Sad abt ay FG SOINVOTOA USHLO tera ; i ' 4 , | (Arhkydsod-47999q SUT PNT oUF) g o°6 g Pe ea eG. Gio Ty. 2. ye, OO, Sane OE } ) L, ee I1vsva poe , (sayoud 04790%q JuFpntout) d 3°8 GO (Eee. ee Sane Pde ge Oe OO Se see ge eee o a OUuddvo pus ALIUOIA 0 g 4 L eeie Se sf Os et Oo: OO 0. Oa 0 2 9 | SSIAND UVdSCTId-ZLUVNd ' eer ana: nee . ; peo (0 im \ ‘ 1 (ogyqnuBod foyttdu foqy Je a f Ce, -una3 pyonntoud Jutpntout) 09 _ &b 99°, 449, 24109: 46 9h 94° Th «OL 29; 29, Te’ 69; ¥T9 ™ ALINVUD 2 a ceope dnvie . “"' ggumyugpton’y) frofownoyuy bo ve eer So ace 4 F % 2 &€ S$ £4 ZF Bw ' KH 7, Aq suozzoottoo quovesdos cust iy . . ] pojvuszsop so0T4TTvooT/_ SANIVUOH dO ANIVUON ANIVUON NIVId : ie . T-1 tkat{vooy OTaONG. SIDTAGNUG 6 RE > ded GtE te “06 “i 99- 9 10-0 I9-D 98-4 OF-0 ZI-0 Lb- ae 0 a6- 0 As 7 JO VaUuv SQUVZZNG = aAIdISVH r ’ SdoOVUaAAYV v2 OTQUy el sokowsyzouy puy 4Temuzptog ‘20490 gqao0o0 advo GHL NI OS qeey 09 4aug oN 0 ‘NIVId $ a Taaad Bquq yuno0eU04S : aagiaid “@adHsvuy ‘g 0 0 7T 0 Hii T T 0 Or eal eot | 0 O-:.0::108 of; .o ! Aad oak + Or 0 Oe wt $9 b 9-6 ub \ fae at 6 Pe Stee $71. | ee 2 2 2 $0 | -+ oe ae Sh g L oS Jig i. that ae a er eG TT at Q°ST yas 9 g g 9! 9.7.(36 (Of + 2 go: bi te Gre | Nome vt ) ) O 3, 0 7.0 \ te nora | 2 | 09 gg TL: 99 9S \ gg i. eu y a re ee odus0ay z2t- L l@tek b2tk 19-4 eatery £Qrd, aye 86-9 0g; 4 1, ONIVUON HOIMANVS dVIUGAO dO VaUv ¥ + y | rae SQMNIVUOWN Q2 8TANL soho anyon, pun ypnaurppon fsouquy aqaoo 9T gf bs Wee $9-9 advo NI 488 euzt0N a Ga ‘ ' fi ng "go: et. 2: Il 9 Ouis0 ee ¢ 9 g pou i es gt QO 9g 99 ., Z UNIVUON AVE sauvzzng ITdaad uqug gunooou04s J0 ADOTOHILIT qsemyynog T 0 C0 ‘Oho. bg fs) eT (O20 ee vee bgt ng eee: ie 9:0 ‘2h «69 % oBusoay 28-0 $170 ve 9 ag 0 5 do - 6L=) 08-9 Ga IMI LNGGINA 4 FLVUGNOTONOO ’ GNOLSANVS Pus ASONYV ZLEVNO NIZA aLIZLUVNS (S4FTT T2183 Zutpntourt) aqiIvis (ouoqsueer3 Qutpntout) LSIHOS (so0t4sutooshd pun o4fToAys ATA 0uU) SOINVOTOA UalhLo (AsAydsod-4qu8nq Juypntour) LTVSVa (payoua Saenor ate Ay pntour ) Oudadvd pur ALIUOId SSIGND UvdsaTad-ZLuvnd (oq 7quudod ‘oattde ‘oeqt -uul2 pfosstouz Jutpnzour) GIINVUD sofousozus’, £4yyumyyptog hq nuotpyzoo,TqToo 4uosesdos 0 poxuUZTsoOp sBOoTATTBOOT /— t£4F [9007 i xs “OBL ae a pit half a mile east of P t of the Pocasset quadrangle, 2) 2 pit northeast of this on Bear Hollow Farm south of Srake Pond, 3) 4 pit one and a quarter miles northwest of Bear Hollow Farm (poorly exzosed), 4) a pit three-fourths of a mile west of Rear Hollow Farm and a mile north of the Military Reservation, 5) several excavations rear a cranberry bog about half a mile southeast of Teaticket Villase in the west-central part of the Falmouth quad- rangle, and 6) a rosdeus at the north end of Pimlico Pond at the southwestern edge of the Sandwich quadrangle. (See Plates I and II). Similar clumps were noted ina pitted plain that extends across the Sagamore and Wareham ausdrangles west of the Cape Cod Canal. Each of the six localities is at the rim or edge of one of the many ket- tle-holes. No climps were found in the hundreds of pits along roads elsewhere on the smooth parts of the plain or in small pits around cranberry bogs that have been developed in the furrows, From this restricted association it is concluded that this till was once asso- ciated with the isoi e masses responsible for the kettle-holes. re composed of till is established by the following characteristics: 1. Fresh rock fiour in the matrix. 2. Abundance of ne sand particles which retain mois- ture after surroundizz zrai 1s dried. 3. Angular ard Fs rock fragments up to one half a foot in length at two exccsures; smaller at the others. 4, Varieties of tre rock fragments,all of which are rock types fourd in the Buzzards Fay moraine to the west. 5. Lack of sorting by water, or bedding, in any clump. 6. Compactness an coherence such that clumps stand out after the surrounding sand is removed. At pach loca lzuy 2 one to ten such clumps were found. Each 9 red rim of iron oxides,2 to 8 inches deep, moosition that pass through the center of ~ediately adjacent is similarly stained. were occur in the uppermost 6 to 8 feet of them reach to the ground surface. ee is evident because overturning and nimals to a depth of about one foot ob- . Below the clumps in each instance and sand. The filling between clumps is rel- = and and fine gravel. the top of sand and gravel of unknown atively loose, non-redd As the climps are a thickness, they must have come into position late in the building of tne plain. For several reasons it is believed horizontal pressure was exerted on the tii! climps as they assumed their present posi- tions. The uppermos ] beds of gravel beneath the clumps appear vague- ly wrinkled into wave-like crests in the spaces 1 to 4 feet wide be- tween the bases of adjacent clumps. At the Teaticket locality the long till clumps stand on end (Figs 6), Near Bear Eollow Farm the Jong axes of clumps ere ali inclined in the same direction. At the National Guard locality, where the till masses lie more or ess horizontally, the ends of many masses form. The horizontal pressure which have been exerted at or near the ‘suri layers several feet below the clumps Such pressure may have resulted at the top of a stranded ice block. Fers Qu. ravidly-fluctuating air temperatures. is temperature far below freezing to aaa it svreads outwar a= other possible explanation is that streams on the outwash olein un- dercut the edges of these ice blocks, causing lerge masses of ice to fall and be dragged short distances in a stream channel. Churks of So stidiefrom the .ice -might).drop directly onto the gravel floor and. be- come squeezed into place under this ice. Subeeriel Furrows The surface of the Mashpee pitted ulair is by kettle-holes, but also by long furrows which the plain -and extend to its ourer edrce. fe miles long. The lower parts of the larg by small streams such as Coonamessett Rive Falmouth quadrangle, but these rivers are ’ furrows today. . The lower end of €ach is floo has thus formed such long, narrow bays G * Bowens Fond, and Eel River on the south sg: Erosion rather than Gepostelom teres inasmuch as they are actually cut into th - the plein. : The truncated edges of gr sures on the walls of furrows. Two in 1939 in- roadcuts a quarter of a and a quarter of a mile southeast of Rou furrows have the form of stream-cut val narrow, shallow, V-shaped cut. Down vel 8 increase to 1,000 feet in width end some 25 £ floors of the furrows are broad and sx LOOT § taries enter the main valleys along their sides, a stunted dendritic pattern. like the veins of < narrow leaf. t lle) orientation of urrows one! of 9 seen in expo- res were s¢éen oy ee eee th ach one heads ina ey, & The close spacing of the furrows anc subperae ali.their main: courses are surprising. Some adwacent furrows ere so close where they enter Nantucket and Vireverd Sounds oes the Slac= topped remnants between them are rarely as much as one half e mile Soroad. All of them are oriented within 20° of seuth, some trending he southeast and others southwest. Those near the western edce of % plain are nearly parallel to the Bu 5 i fre an are ag rangement of valleys is not like pattern formed by’ so many streams in New En 1 erefore, Aeeumiees some special explanation, What sort of erosion might carve such velie are not now occupied by streams, presenit-d edequate to account for these forms. AS %& h rectly connected with moraine areas,and es the peat is not 4 braided one, Cividing and rejoining, as) among. overloaded streams, -they were net cut ty the «same streams of ‘glacial meltwater that once constructed the viain. is kas been suggested that'after the plain was essentially; conslste, the extra supply of water ‘from ice melting west and north of the moraines saturated the loose gravy- uis\e This ground wate rave reacned the surface as springs part way down the fan or the surface. from there to the sea. - A seconda-: 3 is tnt there was-a period of barren, treeless climate, 3 oy drouth or cold, during which ephemeral rains cu 3 sis in the gravels. Another sug- gestion is frozen ground, generated by the t rigorous cold conditions while the ice shéet . still covered ‘the: ir terior of New England, x=sce-+alil excest surface-.gravels- “impermeable to water, and induced tting in closely-spaced channels. Persistence of Buried Ice The duration of all tre everts that contributed to the shaping of the present Mashpee pitced plain is very impressive, The first event was the separation of larzse masses of stagnant ice from the wasting ice sheet. Then,oraided streams of meltwater deposited sand and gravel, layer d and over many of those bodies of ice before h fhe period - required for the con- struction of: s: ee ia nich now contains more than two cubic -miles -of must ce estimated in many tens -and perhaps hundreds of years. “In the surface of the pla here are many thousands of stones which were plainly c : 2 faceted by the wind. ‘These may be found sinsly or in cz oy nearly half of the pits now exca- vated in the plain. of these ventifacts and their abundance impress « muwith the vigor and ‘duration of the wind acti tha m responsible for them. No com- parable wind most of the Cape-today. Ilany -of fe) these eancient venti nei 2 ly in the beds of gravel near the surface of the plaiz : ould not have rolled far in the streams which built- = i vane plain or the delicate polish Dif i rave been’ obliterated. It rs -nec= % | completion of even the upper layers ps hundreds of years ‘during sand and gravel of the plain all fer none of the sand or’silt that teols for’ the sandblast is found rmors, the furrows were cut before Z rurreyws are found to enter and exit 1 El o the ice Pa) ii rom grouss' of ket ro change of direction. There is no sign that raing one kettle-hole to another. - Dozens of small pits occu of furrows, and in-sSome places large pits interrur wnole headward section of furrow from its -lower flo SEA. Had these low kettle-hole depressions existed rs were cut, they would certainly rave been filled with strean gravel. to the level.of..the channel FIGOrs As this is not true, it is inferred that the. blocks of ice rerained not only until the plain was built but also until the fur- rows hac been cut ; Moreover, some of the buried ice was present when .the adjacent men ines Were supsrimposed upon the edges of the plain... Thin active ice moved forward over this gravel and deposited till without de- stroy ing the ‘layers of gravel beneath. Masses of decaying ice caught eer the first outwash gravel. remained until the active ice over- ode them, inasmuch as certain large kettle-holes already described (Page 23) extend from the exposed surface of the fan into the mo- raine-covered area. The ice finally melted away afttar both the grav- el of the fan and the till of the moraine had been deposited, f£, then, ice lasted many tens or a few hundreds of years while tre plain-was being: built, afew hundreds. of years while, ventifacts rere being cut, ‘and perhaps many score years while the furrows were being eroded and moraines were being superimposed, it may be stated with confidence that this buried ice persisted at least for several centuries. It is probable that vegetation had gained a foothold on Cape Cod long before the last buried ice had melted or evaporated. ~ ‘The final event that bisector the cere aspect of the Mashpee ted plain was the drowning by the sea, At.no time .since comple- ion of the plain has sealevel’been higher:on: this: portion of -Cape qd than at is today, for no sandbars were. found. above the modem ore line. These would certainly: be -_present had wave action once been higher on such a-sandy shore. Moreover, none of the kettle- holes at the lower edge of the plain-are filled by wave wash. On the other hand, submerged stumps of cedar trees have been dredged from below low tide- level at Witchmere Harbor in Farwichport, 15 miles east of this pitted plain’ (2, Page 25),and at Centerville (4a) near its eastern edge. The lower end of each furrow is clearly rowned,and no process of shore erosion orconstruction could produce such a deeply indented shoreline. Sometime within the last 10,000 years the sea rose toits: present’ stand with respect to all this sec- tion of Cape Cod,and andes were built acrass many of the bays and estuaries. : Ground water, ' which ecireces the sand and gravel under the plain, rises to a height somewhat above sealevel. In the higher northwest portion of the fan only the pits .80 or more feet deep are low enough to contain open lakes... Along the lower southeast edge even some of the shallow pits 10 to 20 feet deep contain water. These indicate the uppermost level of ground water, because the top ‘of the saturated zone in gravel can stand but ‘little higher or. lower c the surface of open lakes -in depressions. For never-failing supply; all wells must be sunk to this level. Four miles from apex o@ the fan this water table is about 60 feet above sealevel. drops systematically southward urniti1,10.to 12 miles from the apex the fan, it coincides with sealevel. +: It slopes more gently than a) h aan Prone the surface below which it lies. Therefore, wells will vary in depth from 80 feet in ene eee Flat parts of the plain to 15 or 20 feet near the lower e Low, wave-cut ses facing-narrow sea beaches have been eroded along. the low margin of the plain, if “the original gentle surface of the plain be projected out in imagination beyond the present cliffs until it touches sealevel, it appears that the plain once ex- tended from a quarter to, half a mile farther seaward. Waves and shore currents have beaten the shoreline back by this.amount. At distances greater than. half a mile off the Falmouth shore today, or one mile off the shore at Cotuit, the Coast and Geodetic Survey charts (No. 1209 especially) show a drop-off that is far too abrunt to be continuous with the original surface of the pitted plain. If the pitted plain once extended beyond that line, recent excavation by currents,or wave cutting at some lower stand of the sea,has modi- fied the bottom contour too much to allow reconstruction of the orig- inal outer edge of the plain. Buzzards Bay Moraine Location, Boundaries and Character The Buzzards Bay moraine is a belt, half a mileto’a mile and a- half wide, of .boulder-strewn hills and-dales, knobs and hollows. It extends in almost a straight,line from the nortn-central part of the Pocasset quadrangle southwestward across the northwest corner of the Falmouth quadrangle to Woods. Hole, near the southeast corner of the Woods Hole quadrangle, (Plate I). Thence it curves westward to in-. clude the Elizabeth Islands. pats, is the southwestern part of Wood- worth's (7) "Falmouth moraine. Its northern end terminates rather abruptly in a ragged, cliff-like-edge about 100 feet high that trends almost due east and west,: about a mile and a half southeast of the south end of the Bourne Brides over-the Cape Cod Canal. This slope marks a place -where the ice of the Cape Cod Bay lobe rode forward over the northern extent. of the Buzzards Bay moraine and pushed ma- terials of the latter up into a hummocky ridge. When the ice re- treated away from this ridge, the material slumped to form the steep slope facing northward. Many of the irregular hills in the northern part of the moraine rise to altitudes of.250 to 300 feet above sealevel; the hig ghest, Signal Hill, is 406 feet above the waters of Buzzards Bay. The bot toms of many of. the wmdrained hollows scattered haphazardly among these hills are at altitudes of only 150 to 160 feet. Southvestward the general altitude of the higher knobs decreases, but the differ- ences in altitude between the Imobs and the kettle-hole bottoms are approximately the same as in the northern stretches of the moraine. In other words; the topogravhy of the southern end of the moraine on the Cape is just as rough as it is in the Bourne area, although the general surface is nearer scalevel. Throughout its entire length the moraine is liberally sprinkled with huge boulders and subangular blocks of rock, some of them as —_— ~~ et aS ‘sharp contrast to the almost boulder-? western side of the moraine has a much less 0 margin. The continuous till mass that Ss the Ground seems to be delimited by an irregular “line” which ranges about 50 to 110. feet above Buy aeeds Bay in tne Frocesset and Fal much as 18 or 20 feet in longest diamete Herciv a five- lacks. an erratic that is not at least be wo fa) a] Ny Or (QS ry e) ™ Lez) 140) e) y hy 6d Oise 0) pitted plain. In general the boulders « near the eastern margin of the moraine. intensify the contrast noticed when one cros PS cctuphy of. the moraine to the smoother, alzo of the outwash plain. The presence of so many isr which are granite similar to the bedrocz many mil northwest of. the Cape,is eloquent testizory to = er of the ice that brought them. On the east the moraine is marked Sy a creminent, discontin ridge of +ill 20 to 60 feet high,heavily leaded with boulders, overlooks the gently-sloping surface of j This ridge or moraine-front can be seen outwash plain about three quarters ofanmil and about a mile north- of the center o Very few cof the boulders perched on top cz out and down the slopes to. the east by fro ao o Oo + quadrangles... West of this there.are only isoleted patches of some of vnich overlie sand and gravel. g t 3 S a part of the.moraine, but are interpreted as local messes of till posited by the ice during its retreat from the moraine westward 4a- cross what is now Buzzards Bay. East of the lize cthere is an almost continuous concentration of blocks. West of 2% tre blocks occur in scattered patches some, embedded individuelly in the fine gravels that underlie nae strip of lower ground,ot th [ either as isolated units or in clusters. vated along this line one can observe sand} ders and lies on top of distinctly-leyered of the pitted plain. This confirms the cso wes deposited by ice which readvanced and nm gravels. The western boundary of the moraine way, Route 28, -at several places between and West Falmouth. Southwestward the bound lower elevations and presumably disappears Woods Hole quadrangle where the waves of cliffs in the till of the moraine. At some places along the western side of the moraine, however, there is no such definite Deundet v= Insves a. -Spicuous morainic landscape merges’ with the main till-cover east,and ex- tencs west of it over an irregular zone cra% E r width up to 4 mile or more. Such a zone may be seen in the e beuveen., the inter- section of the Pocasset-Forestdale Road } and the crest of the morainic belt east of this. ‘umérous pits and roadcuts in this vicinity show that the zone is underiain by i sularly strati- fied sand and gravel which contains scores o engular blocxs. abundantly as do the blocks in interpreted as a gravelly, kame- re large volumes of outwash ac- ows that stood between the re- till moraine. on the east. The indicate that the ice stood near- vy may have-slid or rolled off the melsi f r or v2 ay been rafted out over the water, : fice that broke off. periodically. cown with debris probably lay beneath tr ch FI Ia O° - F ba n these small lakes. ncen these masses-melted, the surface became an ares of tle-holes ant. irresular hills of-outwash. As this area is essentially like the rest of the moraine topographically and was formed at e@lmost the sane tine, this and similar zones. should be in- ‘cluéed in the Buzzards =sy moraine. THerefore, the western: boundary of such parts of the moraize was-placed at points where the .concen- travion of boulders notably and the landscape is more reculare. - Excepting the blocks and boulders, the materials composing the Buzz moraire are almost completely concealed by 2a derse- srowth Shruscery, and trees. Exposures in road- cuts:are comnon,horere ially where a network of new roads has been built throuch y Reservation of the Massachusetts Na- tiozal Guard easy fhe moraine in this vicinity- is also marked with shallow Douiders were blasted to secure rock frasnenss for local 2cciorn progects. ‘Cliffs cut into the till alonz the east shore rcs Say in the vicinity of -Woods Hole provide additioral vies. to examine the nature of the. mate- rials in the southwe Os tre moraine, Most of the morsainx ; urse, made of till. Its thickmess varies considerably piac = piace. Many of the depressions on the rough surface are probably irrecular hollows where the thiclmess of giaciel debris is less than that composing the surrounding ‘hills. In some roadcuts a lt-fcot thicamess of till -is exposed. At some places along the shore, cliffs 30 feet high ‘have been cut entirely in till, anc the beaches in front of them are littered with angular blocks ef rock derived from the cliffs. In fact, any boulder-strewn beach such as that irom Hnlin Point southward to Woods Hole gener- ally indicates that the reishboring cliffs are made of till. Sandy Nature of the Till The abundance of vine trees on the moraine would lead one to suspect that the underlying material is rather sandy, and this de- duction:is confirred b; arses Of exposures. In fact, the till contains more sand.or siit and less clay and rock flour than is com- monly -ypresens in tiil.e: : New England over which the did not yield such large he limestones and shales of 2. The finer muds and clays that would normally develop over an area exposed for a long time to weathering,as was New England before the ice Age, were largely scraped off by glaciers of earlier Pleis- tocene stages, and are now incorporated in pre-iisconsin deposits. 3. The Ruzzards Bay lote which formed this moraine moved south- east across what had probably been a shoreline region before the sealevel fell. Thus it picked up enormous quartities of sand and silt when it scoured away the ancient beaches and shallow-water de- posits that mey have lain along the shore west of what is now Cape Cod Bay. 4, Vast quantities of outwash sand and gravel may have been spread over southern New England by glaciers of earlier stages. as so, ice of the Wisconsin stage would secure a large volume of such debris as it rode over these earlier glacio-fluvial deposits. 5. The moraine was built by readvance of ice over the western margin of the Mashpee pitted plain. Consequently, outwash sands that had been laid at the west edge: of the pitted plain were picked up in the readvance. . Source of the Materials Granitic types of rock make up most of the boulders ir this mo- raine as well as a large number of the smaller stonese The average percentage of granitic types found in seven stonecounts taken at lo- calities distributed along the moraine from north’ to south wes 66 per cent (See Table 2b). This .is decidedly higher than the average percentage of such types found in the Sandwich morainee Quartzite and vein quartz pebbles make up ll per cert and 8 per cert respec- tively of the stonecounts, and these percentages are likewise some- what higher than for such types in the Sandwich moraine, Toward the southwestern end of the Buzzards Bay moraine many fragments and boul- ders of a coarse graphic granite were found. This type of rock was not otserved anywhere in the Sandwich moraine. These differences in the content of the till of the two moraines and other differences to te described. later make it fairly certain that the two lobes that deposited the moraines moved over regions differing appreciably in their bedrock. This is another reason for separating and distin- guishing the two sections of Woodworth's "Falmouth moraire." Many of these stones were derived from ledges of granite that crop out on the land surface a few miles distant toward the northwest and north nd thus indicate in a general way the direction from which the ice advanced. Character of the eral Nearly everywhere the till of this moraine is loosely consoli- dated and can he pulled apart easily with a hoe; tut there are patches in which it is so compact and hard that local residents and well-diggers refer to it as "“hardpane’ Such material breaks irto chips like a rock when struck with a hammer, and it is difficult to sink a pick into it. “Herdpan” <+i11 of this nature can be seen in 2» roadside excavation on tre north side of Blacksmith Shop Road, half a mile east of the Stete hizgmmy, Route 28. Here in 1939 a section 10 feet high was exposed, cut entirely in gray sandy till containing many subangular boulders 7 racze up to 3 feet in. longest, dimen- sion, The upper few? here as . elsewhere is stained a rusty brown by weathering tinct ridge narking destroyed stratification =, -so that it: is. virtually impos= sible -to distinguish 1 from the sandy. till of the mo- Yainee Even the - pre oz is blocks or boulders in a devosit- does rot fuarantee thal area is till because’ such erratics could easily have tecorme ioc outvash gravel from nearby ice. The southern margin e moraine is, therefore, prov- ably much more irrezguler -tsan een indicated on the map. To pilot it in detail. would require igzging --of many long trenches, and this would be. a rar more c operation than is warranted ty the purposes. of the, presexs.-investizatione An uneven and indistinct boundary -like the-one - just described s found at some pleces alons the marzirs-of present-day glaciers in i =) liat aS TOSS a rarrow zone for a time, building moraire in frort of which en cutwash plain develops simultaneouslye p> ps {3 %, ‘3 4 oO ld Q r)) (eo) n Q jo 4 be iW) cl a) wn 1) + yp J ie) a During construction of tre deposits at such places, masses of stag- nant ice, either isolated ?rom the main mass or protruding beyond it in irregular tongues, are curied by -outwash:or by tille Sand and gravel washed out of active ice accumulate in places on top of the till laid by stagramt ice and then covered with more till when tke ice readvances ‘ ritory. Consequertly, a complex nterfingering of gla cio-fluvial materials -is produced. lly the outwash pl 15 up so high that its:materials are osited in--places within the morainic:area - and. fill some of the lows. Melting of ice ther causes so- much slumping in zone of coxntact moraine and the outwash plain that ations of the deposits tecome still more complex and confus- + nd any ridge-lize tiox that may once have existed along @ ps et jp Oy 0 DO jahys FS cdi) > Q) ch be ck ck fo’ G tay raphy in the zone tetreen:the main body of.the Ellis- in which till. is exposed and parts of the - Wareham 3 s gravel may be observed is eSsen- ° he conditions outlined above. It fo) thet this moraine and its - bordering outwash Similtarezousiy in a similar manner. - The moraine de 50 2 rgirs of a pitted plain ty readvance y and Sandwich moraines, but was corn= ortimious tortimvard retreat of the ice front was erable interval during which its. edge: fluctuated rea now coverea by the morainic deposits. : S. norther= side; abous half a-mile southyest of Briggs aac ™ le) Std ow Ph OW ys , yp }4 ts o 5 a) Reservoir, the Ellisvitis moraine --has a: rather. prominent, steep, Louldery margin, which -can te traced easily as a continuous blurt Tor more than a mile. Sass of this a similar area of higher ground (which may or may not te moraine) covered with boulders curves nortneastware ard 20 Hall and, “the bills northeast of it through Vallersvilles bet the tiuff that forms their northern da s not c » or straicht.as the one de- Ge t e smoother topography of Hio rewhat different from that of has not yet beer thoroughly min a zone of irregular topog-~ ~ 48 ~ raphy, however, and the number of large blocks scattered over its surface indicates that it is at least veneered with, if not com- pletely made of till. For the present, therefore, the possibility is entertained that this zone may telong-in the Ellisville moraine. The hills northeast of Hio Hill are irregular and bouldery, and they rise abruptly above the sandy terrain that lies northwest of them. They seem to be continuous with and therefore to belong to the mo- rainee If this interpretation is correct, the northern margin of the moraine continues as a slope that follows for about a.mile the trend of Ship Pond Road southeast of Morey Hole. This northward- facing slope was formed after the edge of the ice had stood against the moraine in this vicinity for some time. As the glacier withdrew, the till. in contact with it slumped to form a steep slopee Lack of any appreciable gully formation on such a slope is a strong indica- tion.that no great interval of time has elapsed since it was: created. The lower ground north of the Ellisville moraine in the north central part of the Sagamore quadrangle is floored with wellestrati- fied sand and gravel. Its surface is pitted, and patches of sandy till or slumped gravel occur in the side walls of the kettles. This is interpreted as anarea of glacio-fluvial deposits. which were spread after the formation of the Ellisville moraine as the’ ice re- ceded to some position to the north or northeast. From the shore of Cape: Cod Bay at Salt Pond an irregular bluff that faces northeast can be traced through Ellisville and Eastland Heights to the intersection of Ship Pond Road with Old Sandwich Road west. of Hio Hill, At Ellisville this slope lies on the southwest side of Old Sandwich Road. Its ‘northwestward trend is interrupted by the large kettle that contains .Savery Pond, but the bluff swings north across the road at Eastland Heights and then curves’ southwest- ward to cross the road again a quarter of a mile south of the end of Hio Hill. Compound kettles containing Big Dugway Pond ard Black Pond form,deep reentrants in this bluff, but it straightens and be- comes prominent: again on the west side of the’ road and continues northward to the road intersection. With the exception of Hio Hill, the land northeast of this for some distance, lies at generally lower altitudes though it is almost morainic in character. The bluff is thus a distinct topographic break, much like that along Ship Pond Road, and it: probably marks a position of the ice edge during con- struction of the Ellisville moraine. There may be justification for considering this, in fact, as the northern margin of the moraine. Reasons for not doing -so and for including tentatively the lower till-covered area northvest of it in the moraine -are given in the following paragravhse ; ¢ A belt of morainic topography studded: with boulders extends northward from Ellisville through Vallersville to the northern courdary of the Sagamore quadrangle. It covers an-area from a half to three quarters of a mile wide, west of the shoreline of Cape Cod Eaye Altitudes in this belt are lower than in the moraine south of Ellisville, and the kettles are not as deepe Numerous gravel pits in this area show a veneer of sandy till overlying layered’sand and gravels; other pits are excavated wholly in sande The till veneer final recession of the and abundant errati i the Ellisville moraines 5 ice northeastward f = fhe send and gra mes Dresent, in art at least, a floor of ceposits over which the ice had advanced be- AE fore it bude the righ sville moraine. Such a gher srourd of the ae floor beneath till is well exzsessd ix cli ffs along the shore on the east side of heast of Vallersville, and may continue soe eae arease Fart of cee stratifi eri ¥ ceen formed during fluctuations © the border 3 Ss producing the moraine. The ean that und ea over which there is no till may have nel of till after the ice had with- Grawn vermanently Southeast of Hio Hill there is 2n almost boulder-free area that is lower and smoother than tre terrain surrounding ite. This trough. is roughly triangular with en apex. about a quarter of a mile north of Savery Fond and its base tetreen =io Hill and Long Swamp. Except for the fact that its surface erea is much larger and is full of small knoos and kettles,this area resembles the local patches under- lein by sravel that are comoniy found within the Buzzards Bay mo- raire. The kettles demorstrate that there were ice blocks beneath it after t thd the possibility that this surface re which ths ice moved, for ar kettle advance, they would have been filled. area is preted as. a glacio-fluvrial deposit that was formed almost comenp sporaneous ly with the adjacent hillocks of till during accumietion of the moraines The irregular ‘mots of till in the area northeast of the- pluf that extends from Salt.Fond trrouzh Sllisville are. essentially con- tinuous: with the materia? i nizner parts of. the moraine. They were deposited only a after the bluff was producede If the interpreta che slope which forms the north- west border sely along Ship,Pond Road) marks a contact. oi raterials southeast of it, then the main bo have stood close to this area, even arter most padi were in place. In other words, tre till de wer terrain were formed during the. same gereral epi oF ice recession as those in the hichber cerr therefore be included in the territory mapped as t isville morainee , i nozthe Wareham pitted-plain is in= shis braqad outwash plain extends moraine to the shores of Big Rut- Suzzards Bay, in the south- sie. Its extent westward ais y of adjacent areas shows that Wareham quadransle, extends Maromet quadrangle, and. occupies much of the southern part of the Plymouth quadrangle. If the gravels between Great Herring Pond .and Cape Cod Bay are included as part of the broad area of outwash materials that were deposited at approxi- mately the same time as the construction of the Ellisville moraine, it is clear that the Wareham pitted plain once extended southeastward beyond the steep wave-cut cliffs at the shoreline. Peaked ‘Cliff,a high point.on.-the shoreline of Cape Cod Bay half a mile north .of Sagamore Highlands, is the apex of a more or less conical mass of outwash gravel that underlies the area east of Great Herring Pond Slopes of the surface away from this apex, altnough they ene Seerrasced by many kettles,suggest that the materials were spread generally southwestward froma _ source (ice border) that lay somewhere east or northeast of Peaked Cliff. The outer.margin ofthis fan of-glacio-fluvial material is ir- reculear. It lies against the Sandwich moraine on the southwest and against the Wareham pitted plain on the west and northwest. Although in general the altitudes of this cone are below those of the pitted plain where the two come in contact,other features indicate that the outwash in both these areas was deposited from ice that lay to the northeast during approximately the same interval of time. Further- more, as an outwash plain is ordinarily a compound unit built up by the overlapping of several cones of outwash, it seems logical uO naan clade this eastern cone in the Wareham pitted plain. The dimensions of this pitted plain are comparable to those of the Lashpee pitted plain; but its surface is much more irregular and pitted. Apparentiy,many large bodies of stagnant ice lay in a broad lowland area, the southern end of which is now occupied by Buzzards Ray,and ‘remained there until buried beneath a great apron of outwash’ that spread southwestward from the Cape Cod Bay lobe. South of Long Pond Vildase,as well as west of the south end of Great Herring Pond, and also in the area between Littie Sandy Fond and Weeks Pond in -the Sagamore quadrangle, there are remnants of a fairly smooth surface that slopes southward ard southwestward. More extensive remnants scored by long furrows occur through the central part of the Wareham quadrangle. These patches of higher ground suggest that the pitted plain once had a cqntinuous, smooth surface that has been almost de~ stroved because of the melting away of buried ice paebiee Despite the .moraine-like appearance of its (pitted surface in the Sagamore quadrangle, the southwestward slope of the ae alist alsa dicated by a gradual change inthe heights of smoother tracts between kettles which range in altitude from more than 150 feet near Long Pond Village and more than 200 feet on Mountain Hill near Ellisville to sealevel at Big Buttermilk Bay. -- - - a The Wareham pitted plain is.not shaped ike a tan with a single apex and a convex outer margin. .Its sur face slopes seem to converze toward several high areas along the southwest side of the Ellisville moraine, and suggest that outwash was fed from several major sources along the ice. front. To locate the exact Eee of these sources is difficult, however, because so many large kettles have develore in the zone bordering the moraine. A gradual but irregular change outhwestward ,in the . size of constituents in the Eravel,fronm coarse See! Bales sand and coarse gravel with numerous boul medium and fine sana with small and relati streaks of coarse gravel at the shoreline, were supplied from the northeast. 2 Abundance of Buried Ice Blocks Furrows that are essentially si those on the Mashpee fitted plain e¢ cross the gently sloping remnants of th rows are most continuous through the Quadrangle where a number of them have remar: es and are closely spaced. Valley Road southmvest ar i md ms located in the bottom of the longest furrow im the Sagamore nued- rangle. Dywo shorter "ones Jie. “a few sales zcrshiese of -tais,one reaching northward for about two miles from tonz Duck Pond, and the other extending in several branches bl G irom were sogs almost to Wareham Road. Many kettle-holes cevelored aiter the furrows haa been cut by surface drainage on the vlain. Foliows haifa mile or more in diameter and from 20 to more than 50 Zee some of then pecupied by ponds, now lie across the furrows, ani sme developed in the smooth and generally flat a = On their seaward ends the furrows become » on the Mashpee pitted plain, created & Across the northeastern part of the é elongate kettles, some of which are excepvionsliy is most continuous depression curving southvier at RBournedale. Ponds fill the bottoms of the iO south these sre: Gallows Fond, Bloody Pond, Little Herring Pond and Great Fora, f aligry ment and elongated nature of these depressi Suet Uns elec along the trend of what was formeriy a lo lievy, new partly filled with Pleistocene deposits. S& an whis valley a considerable length of time. Some before the Sand- wich moraine was built,as isindicated by t: 2Geu shat the souvhern pert of the kettle containing Herring : BSc fe) Diunt e of the moraine at Eournedale. AIL of mained wntil after the giacier ha moreine,for the smooth surface or the ly indented when the ice finally melted of kettles. Till Clumps Clumps and larger masses of sanay corigining errati ur at several places in the midst of plain. All these till masses are on the till lies upon outwash gravels. They cally inamanmner suck as was outlined oa » 52 = have teen developeds The till can be seen lying on well-stratified sard ard gravel at several exposures along the margins of the bogse In contrast to the clumps of the Mashpee pitted plain, however, these till masses are larger,cover several acres adjacent to the bogs, and contain many large erratic boulders. = be = Selected References 1) Bryan, K., New criteria applied to the glacial geology of south- eastern Massachusetts (abstract): Geol. Soc. of Amer- ica Bull., vol. 45, pe 176, 1952. 2) Chute, N. Z., Geology of the coastline between Foint Gammon and Monomoy Point, Cape Cod, Massachusetts: Commonwealth of Mass. Dept. of Public Works, Special Paper No. 1, OS 2a) Davis, W. M., The outline of Cape Cod: Am. Acad. Arts and Sci., Proce VOlw. ol, pos COveodc, LEoo, 3) Hitchcock, E., Report on the geology, mineralogy, botany and zo- ology of Massachusetts: pp. 145-144, 1833. 4) Shaler, N. S., Geology of the Cape Cod District; U.S. Geol. Sur- vey, Highteenth Ann. Rept., Pt. 2, pp. 497-595, 1898. 4a) Sawyer, G. C., Thesis on file at Dartmouth College. rles, Re W., Upper till, two boulder clays, and interglacial flora on Cape Cod (Abs. ): Geol. Soc. America, Bull., VOls 90; pp. 1951-32, 1959. 6) Woodworth, J. R., Post-glacial aeolian action in southern New England: Am. Jour. Sci., 3rd ser., vol. 47, pp. 63-71, 1894, 7) Woodworth, J. F., and Wigglesworth, E., Geography and geology of the region including Cape Cod, the Elizabeth Islands, Nantucket, Martha'ts Vineyard, No Man's Land and Block Island: Museum of Comp. Zool., Harvard University, Mem.-, vole 52, 1934, > n . ee Oo oO The following reports on investizetions under the cooperative ogic project of the Massasrusetts Department of Fublic Works,and United States Departmert oF the Interior,Geological Survey, have published or are in process of publication. Reports published distribution are obtainable through the Massachusetts Department blic Yorks, 100 Nashua Street, Boston, Massachusetts. erative seolozic work in Massachusetts for. the year ending De- ember 31, 1938: by L. W. Currier. ative geologic work in for the year ending De- ember 31, 1959: by L. i. r erative geologic work ix Massachusetts for the year ending De- ember 31, 1940: by L. ff. Surrier. Special papers Geology mmon and Monomoy Point, Cape r Ce o (Copies available through the Massach partment of Public Works). Gravel deposits of the Granville quadrangle: by W. &. White. (Copiss may be consult library The seismic method for detern apt in Lowell quadrangle, Massachusetts: by F. W. Lee, F. C. Farnham, and A. Raspes; ntroductory chapter on the geolosy of the Lowell s- L. W. Currier. (Copies available). tne Blue Hills quadrangle: Chute. of western Cape Cod: by a cso! ther, Hs. 4. Goldtizmit, and L.R. MThiesmeyer, in Reservoir area: by Robert Balk. (Manuscript ibrary depositories}. port on the zeoloz; of Northfield quadrangle: by pes for library depositories in éassac atts: ty Merlend P. Billings. deposits o7 Ludlow, Granby, Amherst and adjacent ers Re Weseler. Manuscript copies at library depositories). Notes Annual reports are mimeographed anda small number are available for distribution. Copies are sent to the State librarian, to public libraries at Boston, Worcester, and Springfield, and to colleges and universities. They may also be consulted at the office of the De- partment of Public Works, Boston, and the library of the Geological Survey, at Washington, D. C. Bulletins and special papers include some reports that are pub- lished (in mimeograph form) for general distribution,and others that are deposited as manuscript copies at the public libraries in Boston, Worcester and Springfield,with the State librarian at Boston, at the office of the Department of Public Works, Boston, and at the library of the Geological Survey, Washington, D. C. The public may consult the manuscript copies at these library depositories. Unless other- wise indicated a limited number of the reports is available for pub- lic distribution through the Massachusetts Department of Fublic Works. Published reports may also be consulted at college libraries throughout the State. Some or all ofthe reports now available only in manuscript form may be published at some future time, and will then bear the publi- cation numbers assigned to them as manuscript copies, oe NANTUCKEZ SOUND SCALE MILES FIGURE 1 OUTLINE MAP OF SOUTH EASTERN MASSACHUSETTS, SHOWING QUADRANGL ES INVOLVED IN THIS REPORT. SHADING /NDICATES QUADRANGLES INCLUDED IN GEOLOGIC MAPS, PLATES I AND ZZ. San ariwos osz ooz ost oo! os upysosgaNn ty puod UBIOUNIT uosuoy |: tsabpis jp1op|6 sa4o] Duiinp pasano> jou syisodap ipiaD15 sauipsow Jo volingisisip hq payosipuy so *abojs UisuozsipA bulinp yuosy a1 aU} fo suoltisod aaissazong *UO!LD]NWNI20 4O Japusd uD esoposqgo > WO} aot (SYFINLO ONY HLAOMOOOM'AFT7IIS L42AFAIT AG AIOTOII) SLIFHS FI INFIOLSIFIA AD WIATFAOD FAIMLYHL SUFAY OMMOHS CHAINS HLION NAFGLSYFHLAION SO AGW HILIANE 2 77Ng/7 "FE FHNO/S IO SUFAY OIILCHS OL INOISSIYA -Y02 O2N/7LNO SITONSAOUNO FHL ANWMHLOTOD MP ONYNIOTY IM HLIOMIOOM BP 'YTTINS TW IO FSOHL Jee IW IALIO NINMOWS SITONGSOLNIO FHL IWSLNO SIMHUZL W/IIGTI SO SNO/LYLIASAFLNS FHL ‘ONG7S/ 2NOT ONY ONEYTONIMIN NAFLSYTHLIOS IO SUFI MUTA HSUMLNIO ING SINILAON INIMOHS ALW HILING £ FANIIA s3qtIw anrvos f og 02 O1 "SSOW Usajsoa UI Saqoj Jof ow pud fUaWAAOW 331 4O SUOI4ZIIIIP paz!}DJZUIO x \\ \ -1aA036 puo pups ysomyno hq fAyisowssd ulpjsapun soasy [E (aboyg uisu03s!m) SJIIDOIN GUE JO SAUIBDIOW 4SOWUIOYENOS ON3931 ee ny UeN 4 hau 4) hv aa nen ! uy MG nga hh Ov fh TGvOLLEVH & 3 uv - ° vu ® c iS 0 _ ane : i f}amasina ® TT, Yi, ca Wty |e y/ Fi Y Vy y} FIGURE 4. SKETCHES OF WINDOCUT STONES FROM GLACIAL DEPOSITS OF CAPE COD A-ROUNDED COBSLESBEVELLEO BY WIND-CUT FACETS. B-PYRAAIDAL VEN TIFT FORMED BY INTERSECTING FACETS. C-OFEP GROOVES ANDO FURROWS ON BOUL OER. O-ANGULAR VENTIFACT ROUNDED BY LATER ABRASION. E-DEEP FLUTING ON GRANITE BOULDER. F-PARALLEL GROOVES AND PITS. SSE EEN AEN ET o disturb sree Zo Sy Ho; FIGURE 6 DIAGRAMMATIC SKETCH OF T/LL CLUMPS IN GRAVEL P/T NEAR TEATICKET 0.5 SCALE MILES o Y rane SO Pee EZ Hills of till deposited during Outwash sands and grove/s BA retreat of Buzzards Boy Lobe. forming pitted plains. FIGURE 7 SKETCH MAP OF PART OF POCASSET QUADRANGLE SHOWING PRESENT DRAINAGE IN AREA OF GRAVEL FAN THAT WAS DEPOSITED BETWEENTHE BUZZARDS BAY MORAINE AND THE BUZZAR0S BAY (CE LOBE INA POS/TION OF ITS RETREATAL STAGE. * ACCOPRESS® NO. 2507 BF - RED BS - TURQUOISE BG-BLACK .. BQ-PALM GREEN BD-LT. GREY 8X- EXECUTIVE RED BP~LT. GREEN BZ - DARK GREEN BU-LT. BLUE BA- TANGERINE BY- YELLOW 8B - ROYAL BLUE SPECIFY NO. & COLOR CODE ACCO DIVISION OF GARY INDUSTRIES, INC. CHICAGO, ILLINOIS 60630