iilliiiliife ■■liii CORNELL UNIVERSITY LIBRARY Cornell University Library QE 124.D31S54 Newly exposed geologic features within t 3 1924 003 943 382 Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924003943382 NEWLY EXPOSED. Geologic Features WITHIN THE OLD "8000 ACRE GRANT," BY GEORGE SHELDON & J M. ARMS SHELDON. Copyright, 1903, BY George Sheedon & J. M. Arms Sheldon. HART Si. VON ARX, ENGRAVERS a. PRINTERS. NEW YORK, NEWLY EXPOSED GEOLOGIC FEATURES WITHIN THE OLD "8000 ACRE GRANT," BY GEORGE SHELDON & J M. ARMS SHELDON. Recent excavations have bronght to light interesting geologic featnres within the boundaries of the old " 8000 acre Grant," given to Dedham by the General Court in 1665 — the nucleus of the town of Deerfield, Massachusetts. At Wapping Long Hill, about two miles south of Old Deerfield Street, on the west side of the road to Bloodv Brook the scene of the Lothrop massacre, a section of a sidehill was exposed in the summer of 1902 where forma- tions were seen of unique structure and most striking aspect. The exact location was a few rods east of the deep clay cutting of the Canal Railroad, south of Wapping village, and a few feet below the rails. In the illustration (pi. I,* looking westward) the sky line with telegraph poles is the top of the west scarp of this cutting. The new exposure is in the middle ground. This is about 150 feet long and fi-oni 16 to 26 feet deep. Nearly one half of the new sec- tion is not seen, being in a pit below the level where a man is seen sitting under a tree. What appears to be two low hills just above is the line of the east scarp of the railroad cutting, here broken through by a rain-made gulch, now partlj' filled with debris. ^ The upper part of this section is soft, stratified clay from three to ten feet in thickness. This clay rests uncon- formably upon a formation of variously colored sand. At the left of the seated figure the sand rises like a dome, and dips away to the north and south. The line of demarcation between the clay and sand has never been disturbed, and is remarkably well defined. On the south side (pi. II, view from the east) this line is em.phasized by the soft clay that has run down upon the sand and turned white in drying, making irregular white streaks (pis. I, II). The sand has been excavated 26 feet from the surface but its depth is un- known. Generally speaking, the south part (pi. II) is a solid, perpendicular wall of sand and clay as left by the workmen. *Pls. I — VI, VIII — XII are from photograplis talten under the direction of the authors by Frances S. and Mary E. Allen of Deerfield. PI. VII is from a painting made expressly for this paper by Augustus Vincent Tack, of Deerfield and New York. The sand is finely stratified, and the sand of the dome is of a peculiar pink shade. This pink sand is entirely free from iron rust or limonite, and other impurities ; it is as clean as any beach sand, and will not soil the daintiest linen. The face of the sand has lost its moisture, and when touched by the trowel the sand flows almost as freely as water. Under the magnifying glass this sand is seen to consist of frag- ments of crystalline rocks like granite. Grains of glassy, white and pink or red quartz greatly predominate, but scat- tered through the mass are tiny scales of white mica, withi bits of slate and mica schist. The most remarkable feature of the exhibit is at the apex of the sand dome, where the pink color' is most pro- nounced. As left by the shoveler the bank was vertical, with three feet of dark clay at the top, the sand disappearing below in the pit. The cunning hand' of Nature has since worn away some of the sand, leaving the upper segment of the clay-arch a projecting and protecting cap. As the surface dried at this point the sand crumbled off or was blown away by the wind, and here is the marvel ! The upper part of the sand dome exhibits a beautiful columnar structure (pi. II) exposed on three sides, and so noticeable was it that one of our party exclaimed at sight — " Look at the Giant's Cause- way !" And there it was — perpendicular columns of sand rising one tier above another, clear, sharp and distinct; some broken off at the middle, others nearly reaching the 'over- hanging cap of clay. The day after this discovery was made photographs were taken. The following day a heavy storm of wind and rain swept away the wonderful columnar pile and the protecting cap of clay. Will the like of this ever again be seen ! Can any one tell what agency pro- duced this remarkable structure 'in the midst of the dome, and held the friable sand in position while the oiitlines of the columns were being exposed by the delicate manipula- tions of the wind ? This formation could never have been carved by the hand of man. The least touch set the sand aflowing, and the angles instantlj' melted away. Was it that mysterious force of Nature, hidden away in the earth, which is constantly striving to bring order and beauty out of the shapeless mass, and which is revealed in crystalline forms ? This ma)' be, but there are other forces to be con- sidered farther on as a probable, or, at least, a possible cause. At the centre of pi. I, and north of the pink dome, the earth has not been disturbed by the shovel. In marked contrast with the pink sand, and separating it from the brown sand to the north, is a layer of coarse, ochre-yellow sand, colored by oxide of iron, and apparently dipping under the pink sand southward. From this point the ochre-yellow layer rises northward, and is seen underlying the clay across the whole extent of the north half of the exposure. At various points on the line of juncture the yellow sand and the clay are mixed and kneaded together in compact masses. Under this ochre sand lies in gently disturbed layers, a mass of fine, brownish sand, very different in composition and color from the pink sand, the lowest development being an undisturbed coarse, red sand. At the extreme north of the section, and only seen in a pit below the present level, another rounded mass of the pink sand is exposed, overlaid with the brown and the ochre-yellow sand and the upper clay before described. So far as we can learn from geologists this pink sand, or something similar, occurs in only one other place in the Connecticut Valley. In a cutting of the Canal Railroad, nearLaurd Park, in Northampton, Professor B. K. Emerson found and described a mass of what he terms "peach blow'' sand. He calls this part of " a true sea beach of great ex- tent," and sa3'S " it is older and unlike anything else in the Valley."* In comparing samples of the pink sand at Long Hill with samples of the "peach blow" sand from the Laurel Park cutting, we find that the two are similar in structure, the chief differences being that the pink sand is finer and con- tains a larger proportion of red quartz and of slate and schist. About ten rods east of the sand formation just described and on the east side of the highway which has been recently widened, quite a large face of the scarp has been exposed. And here is another extraordinary exhibition seeking ex- planation. This formation is chiefly Champlain clay, and the dark, tenacious layers alternate with those of a lighter hue and more friable structure. This friability is due to the "quartz flour" contained in these lighter layers, which is so fine that the "gritty feel" cannot be detected by the fingers, but only by the teeth. Here we see (pis. Ill, IV) the upper part of the clay exposure lying in horizontal, undisturbed strata. This is clearly a later deposit. Below, the strata are crowded and contorted (pis. Ill— V) ; plainly this was the effect of some powerful force exerted from the north. Towards the south end of the bank, seen in pi. VI, the strata show less and less * U. S. Geol. Surv. Monog. XXIX, Geology of Old Hampshire County, Mass., p. 696. disturbance. It is here that fine ferruginous concretions (see pi. VI) stand out abundantly from the nearly vertical face of the bank. They vary in shape and also in size, though they are . generally cylindrical in form with concentric yellow rings which grow fainter towards the circumference. Unlike the familiar "claystones" found abundantly in the clay beds of the Connecticut River, usually lying horizontally within one layer or in two layers, these ferruginous concretions are generall}' nearly or quite vertical, and pass downward through both the tenacious and friable layers. Each con^ cretion has a distinct nucleus, usually a tinj^ rootlet or twig. Sometimes the woody matter of the nucleus has been re- markably well preserved. Such a nucleus w^e found running from a light layer entirely through the underlying dark layer, and though the latter was not so strongly colored as the former, yet distinct concentric lines could be seen when the concretion was cut diagonally. In seeking an explanation for the anomalous condition of the pink sand and the contorted clay we shall venture upon assumptions which seem to be supported by careful observation of facts. In a far-off age, although recent when compared with the old geologic periods: — later than the time indicated by the intensely interesting exhibition of glacial action seen at Greenfield : — after the drift and heavy deposit of Champlain clay in the Connecticut Valley, there came a time when the Deerfield Valley from Cheapside on the north to the scarp of Long Hill on the south was denuded of the clay to a depth indicated by the top of Pine Hill, Meetinghouse Hill and Wapping Street as seen to day. It was at this time and in this condition of things, we shall ventare to assume, that the last invasion of northern ice filled the basin of this valley. A belated glacier, the last of its tribe, wandering down from the northwest, struck its southeast front against the high trap ridge at Greenfield. Following this ridge which narrowed southward to a point at the east end of the gorge at Cheapside, it was confronted by the high, bold cliff on the south side of the river — now being cut away for road material — which forced it eastward thirough the gorge. In view of facts to be presented we assume that in attempting this passage the gorge was found too narrow, so that a split occurred in the moving mass at the point of contact with the towering cliff on the south side of the gorge, and the south- westerly, detached lobe continued along the westerly side of the Deerfield mountain until it butted against the steep scarp of Long Hill where its diminishing force was spent along the line of the identical spot under consideration. There was evidently then as now a wedge-shaped ravine in the face of the scarp at the point of contact. There is evidence that this lobe of the glacier rested here for a long period and here finallj' melted. It is a law in glacial action that the central portion of the glacier moves faster than the sides or bottom. Conse- quently the fragments of rocks torn from the sides of the mountain in the passage of the glacier, and falling on its surface, graduall}' work themselves towards the median line, forming there a stream of debris. The split was probably at or near the median line, for scattered along the western slope of the Kast Mountain are found glacial bowlders Iving upon the surface, some of immense size, which may have been from the central mass of debris, and which rest where thev lO were left on the dissolution of the ice. The turtle-backed top of one of these bowlders, lying half a mile from the north end of the Old Street, was a favorite resort for us bo37s, who could scale it on the north end. This was destroyed in building the Connecticut' River Rail- road. This movement of the ice is apparent to the lay ob- server, and the following extracts from the scientific geologist strengthen and confirm our own conclusions. Professor B. K. Emerson, in his Geology of Old Hampshire Countj-, p. 442, while describing this region, says: "An exceptional rock occurs abundantly in bowlders on the south side of the Deerfield River, but I have not met it on the north or in place." Alay we not conclude that these exceptional bowlders are a part ot the central debris of the divided ' glacier, and that their " place '■' must be looked for in the far northwest ? On page 509 of the same work is a description of the trap ledge at the exact point of the supposed split. "Tbe talus was exposed for a length of 90 feet and for a height of 30 feet, and it apparently extended down to the level of the river, 50 feet below, but this was not observed. Covering this talus and extending up over the trap was a layer of very compact till, 30 feet thick, of reddish color, made up mostly of sandstone with few bowlders of mica-schist from the western hills aud with none of trap. At least nine-tenths of the bowlders, down to those not above two inches on a side, were finel}- striated." This is exactly- what would be expected in the event bi the supposed division, as a large amount of the ground moraine would naturally be here dropped. The "sandstone" was doubtless gathered up by the glacier just before its contact with the trap. The next extract (p. 509) also strengthens our view: "A fresh vertical section of this till produced bv caving, was mai'ked for a long distance by wavy lines of apparent bed- ding, so perfect that at a distance I had svipposed the beds to be the thin-laminated Champlain clays, but the lamination proved to be an unusually perfect pressure cleavage in the till, in planes dipping 60° to 70° N\V., at right angles to the direction from which the ice was moving in the can3'on [or gorge] as marked by the striae upon the trap im- mediatel}^ above." Here, again, is a perfect descrip- tion of the effects of tremendous . pressure at the part- ing of the ways — at the exact point required by our theory. Perhaps, however, the most direct evidence in support of this glacial theory may be found in the final efforts of the moving mass of ice, as seen in the distorted clavs at W'apping Long Hill, already referred to and represented by pis. IH — V. These plates show the contortions of the lower exposed layers of clay which are bent, curled and crushed at the north face, the disturbance growing graduallv less to the southward. Similar .evidence is found in the distortion of the layers of sand underlying the latest clay deposit, which, on our theor}^ must have come in direct contact with the moving glacier. The dome-shape of the pink sand was apparently due to the powerful horizontal thrust of the ice forcing it upward through the overljnng sand. A heavv, vertical, downward pressure by the overhanging front of the glacier or by the. subsequent clay deposit upon the moist sand may have caused this friable material to take on a columnar structure, and retain its form under some unknown law of nature. Differential shearing, or a sliding motion, caused by unequal pressure, has been considered as a possible agent in the formation of the sand prisms, but a careful study of their structure and surroundings shows, we believe, that here no such process could prodxice such an effect.* One other cause has been suggested as a possible solu- tion of this unique phenomenon. There is evidence to show that the towering ice mass held its own in our Valley with- out melting for an indefinitely long period. During this long contact of the glacier with the moist, quartz-laden sand the latter must have remained in a solidly frozen condition. Can it be that the Frost King, whose operations we see in the varying forms of ice crystals above ground, is respon- sible for this prismatic structure? The clay overlying the columnar sand must have been laid down while the glacier occupied this valley, for when the glacier finally melted no trace of clay was left in the valley where it rested. In the northeastern corner of the old "8000 acre Grant" we find another remarkable exhibition of the works of nature. How many of the people of Greenfield know what interesting geologic features can be seen in their sequestered Highland Park with its combination of the rare, the beauti- ful and the economic ? The western slope of the trap ridge, already referred to, now presents for a considerable distance *We are indebted to Professor W. O. Crosby, of the Massachusetts Institute of Technology for an opportuuity of examining fine specimens of slylclitic linie- stone, produced by differential shearing. 13 in bold, striking relief that peculiar columnar structure whicli has long made famous the Palisades of the Hudson, FingaVs Cave and the Giant's Causeway. This ridge is volcanic rock, usually called trap, but known to geologists as diabase. It comes prominently to light at Turners Falls, and, at this point, forms the buttress which shoulders off the Connecticut River southward. It is the eastern wall of the town of Greenfield, separating it from the Connecticut, and known as " Rocky Mountain." To the south the ridge falls off, as we have seen, and narrows on its western flank to a thin wedge when it reaches the gorge at Cheapside. This gorge may have been caused b}- a crack or a perpendicular fault which has been enlarged by the pas- sage of ice and water. The south side of the fault, if it be such, presents a bold, broad front projecting towards the west. Through this deep gorge in the trap ridge the Pocum- tuck River finds its way out of the Pocumtuck A^alley into the Connecticut. Beyond the gorge, the range extends southward, forming the eastern section of the " Pemawachu- watunch " of the Indians, the " Deerfield Mountain " of the map makers, and the " East Mountain" of today. This trap ridge culminated at Hosmer's Peak, just southwest of the notch in the ridge through which runs the highway from Deerfield Street to Pine Nook. At this place there seems to have been an excessive outpour of the liquid lava, with an intent to flow westward, but the broad, stout back of Pocumtuck Rock interposed a barrier against which the hot mass humped itself in vain. It finally cooled off, the two became friends and have steadilj' backed each other until now. 14 It would appear that at this rebuff the lava became dis- couraged for the ridge suddenlj- dips to the southeast, disap- pearing under Sugar Loaf and the Connecticut River. The western escarpment of the "Deerfield Mountain" is red sandstone, which reaches its greatest elevation — 822 feet — at Pocumtuck Rock. In several places along the trap ridge the interesting feature known as columnar structure is developed. On the west face of Hosmer's Peak are found the columns which we suppose to be those described by President Edward Hitch- cock.* He says: "Along the west side of the greenstone ridge that forms the eastern part of the Deerfield Mountain, in several places, about a mile east of the village, they [the columns] exhibit great regularity. Usuall}' their diameter here ... is between two and three feet ; rarel3' as small as one foot ; and the number of their sides between four and six. The)- are sometimes distincth' articulated; the joints varying from one to three or four feet in height. The joints are usually curved, at their ends, presenting frequently a convexitj' on the upper side, and a concavity on the lower. The breadth of' the sides is considerably unequal, and with this exceptiqn, thes^ columns might , compare in regularity with those of basalt from Ireland." On p. 643 he saj-s that the columns at Deerfield are sometimes considerably curved. Professor B. K. Emersont speaks of this cliff as looking " down with vertical wall upon the village of Deerfield at its foot. It shows just east of the \illage the finest columns in the State, two to three feet in diameter and in places dis- tinctly curved." One might suspect that Professor Emerson •Geology of Massachusetts, Final Report, Amherst, 1S41, pt, III, p. 641. tGeoIogy of Old Hatnpshire County, p. 441. 15 had not visited this spot, but had taken the story from President Hitchcock whose language he had misapprehended. The trap range does not directly overlook the village, the sand- stone range west of it shutting it off from view. The above record is all the literature found relating to these columns. The columns are not continuous but occur in small groups, and are from eight to ten feet in height. We found two columns measuring in diameter 36 and 45 inches respec- tively, while the only two exposed faces of one large column measure together 55 inches. The most striking feature observed was the cur\ed upper ends of the columns of one group, appearing as though a strong force had bent them toward the north. These columns are not easih' accessible, since they are concealed by a vigorous growth of young trees and a thicket of high laurel. So far as known they have never been figured; w6, therefore, here insert pi. ATI, although not quite germane to our paper. In this plate four large columns are distinctly seen, one of which is broken off at the lower end. In the upper right hand corner are the broken ends of two overlying columns. The column to the left shows three faces, while the others exhibit only two. Owing to long-continued weathering the sharp angle originally formed by these two faces has been worn off, giving a more or less rounded appearance. The curved upper ends of the columns, however, are plainly seen in the plate, and are most impressive ill the rock itself. In striking contrast with these time-worn and forest- guarded columns, beautiful with moss and lichens, are the columns at Highland Park, recently exposed in furnishing material for the maw of the insatiable stone-crusher. For the distance of perhaps 'So rods these columns may be i6 traced, and for a great part of this distance they are wholly uncovered. They are now for the first time figured and described. The exposure at the south end (pi. VIII) is the finest. Here one faces a sheer cliff 75 feet in height, run- ning north and south, with an inclination of about 20° east. Near the centre of this exposure, for a width of 40 feet (not seen in the figure) the cliff is smooth and bare from top to bottom. To the right and left of this space, and lying against its face, are rows of massive columns, some of them 25 feet in height. Generally speaking these columns seem to be quite regular in form, and appear much like a flight of stairs turned over on its side. From a little distance or upon a cursory glance the lines appear straight, and the treads and risers of the supposed stairs appear to be plane 'surfaces. On close examination, however, it is seen that there is not a really straight line or plane surface in sight. All the sharp edges and all the flat sides swell in gentle curves as though the columns were straining or staggering under an enor- mous burden, although none can be described as "bent." In shape they are polygonal, the prevailing form being pen- tagonal, although we occasionally see forms approximating squares, parallelograms and hexagons. In size they vary from one to three feet in diameter. The columns are cross- jointed (pi. VIII), with the: same rule of irregularity prevail- ing. The exception to this rule seems to be that by no accident is the cleavage in the cross lines exactly straight. The quarryman finds that no single section can be pried out of a column while in place ; the dislocation must be from one end. Some of these sections have a more or less perfect ball-and-socket joint, but as if to complete every possible 17 irregularit}' in structure we find some of the overhanging ends convex while others are concave. We do not discover any perfect illustration of the law of crystallization or of the law of prismatic jointing, nor is there anj- apparent cause for the prevailing contradictions. PI. IX shows another group of columns in a similar position about 40 feet to the north. Three of these columns measure 15, 18 and 20 feet in height, and their exposed faces measure respectively 24x19, 24x30 and 23x19 inches. The}' are of the same character as those in pi. \TII.' The bare space between these two groups was filled with the same kind of columns, which were removed by the road- makers, so that the formation was originally continuous. Several other series or rows of columns — perhaps half a dozen — Iving against those in place have been broken down and remo\'ed, and we see their upper ends projecting over those in place. The overhanging brow thus seen may be called the coxmterpart of the Titan's Piazza on ]\It. Holyoke, figured and graphicallv described by President Edward Hitchcock,* onl}' lacking the convex ends shown in his illustration. This overhanging mass left by the destroyers when the columns were broken down was continuous across the face of the cliff, but the central part has been removed, leaving the sheer precipice first described. A few rods south of our point of observation (pi. VIII) the rock has been taken out about 25 feet lower, but the face of the cliff thus exposed is of another character ; there are no . signs of a columnar structure, neither is there anj- appearance of an underh'ing sandstone as seen in pi. XI. *Geology of Massachusetts, Final Rep., 1841, pt. II, pp. 245, 246. i8 There is another unexplained feature in the structure of the columns, but it is in keeping with the general irregu- larity of the place. In pi. VIII, going from south to north each column overlaps the next north of it a few inches, that is, to continue the stair simile, the tread buts against the riser. In pi. IX, and in all the other examples to be mentioned north of it the reverse is true, the riser butting down upon the tread. The place where these two opposing systems must have come in conflict is in the cleared space of the cliff, so that an interesting point of observation is lost, and there remains no hint upon which to hang a suggestion. This clearing on the face of the cliff, however, has brought to light a feature of larger import which plainly confronts the geological student, and which should have sooner en- gaged our attention. Across the face of the cliff, some 28 feet from the base, runs a clearly defined horizontal division line. Hardly distinguishable from the d6bris at the bottom runs another line nearly parallel to that above ; between these two lines are the nearly vertical columns. This series of overlying columns, then, formed at the south end a band some ten feet thick running north along the side of the mountain, gradually decreasing in width as the columns grow shorter. The face of the rock l5nng back of this band where it is exposed by the removal of the columns is in place, but it is shattered, crushed and splintered into every conceivable angle and form. Once an opening is made these pieces can be picked out with the fingers. No Indian ever owned a better native scalping knife than one specimen we took out of the mass. Other ready-made instruments for war, the chase, the kitchen or field abounded. Whether the rock above the upper division line was in the same con- 19 dition could not be ascertained, it being impossible to scale the face of the cliff. At a short distance north of the cliff we have been con- sidering, high up and hidden away among the underbrush and trees, are a few large, fine columns, which, so far as we can judge, have been exposed by time and nature for an indefinitely long period, and which the hand of man has never disturbed. It is indeed surprising that these coliimns have not been noticed before, but we can find no allusion to them in any geological description of the Connecticut Valley. Owing to their situation, the steep ascent, the rocky debris in front, and the leafy trees which shut out the light, a satisfactory photograph of this exhibit could not be obtained ; however, pi. X shows the structure unmistakabl}'. The largest columns in this view are seen in shadow at the left. The lower portions are wanting, and the exposed ends of the remaining parts show distinctly the concave depres- sion of the ball-and-socket joint already described, which is a marked feature of the columns of the Giant's Causeway. Still farther to the north is another exposure shown in pi. XI. This is of especial interest sihce here the line of actual contact between the columnar trap and the sandstone comes out finely. In the plate a person is standing on the sandstone just below the columnar trap. To the right the horizontal strata of the sandstone are clearly shown disap- pearing under the trap. Towards the left the columns grow shorter (pi. XII)* and finally midway up the shattered face of the precipice die out altogether. As to the origin of this trap range it may be stated as a well ascertained geological fact that in a remote age, after *Tliis plate repeats a portion of pi. XI. 20 the sandstone of the Connecticut Valley had been laid down, and while the whole was submerged, some internal force caused a long 'rent or fissure in it running north and south. Through this fissure the molten rock was forced upward, filling it and flowing over on either side. One or more outpourings of this lava formed the Greenfield and Deerfield trap ranges and also Mount Holyoke, Mount Tom, and other southern ranges. The origin of the columns was formerK' explained by the law of crystallization. It was thought that the mass of lava buried far from the surface cooled more slowly, and in the process cr3'Stallization produced the columns we see today ; near the surface the rock cooled more quickl}' and became homogeneous with no indication of columns. Another theory, however, has now been advanced, and according to the new view, the columns are not in any proper sense crystals or the result of the action of the law of crystalliza- tion, but are regarded as due to the shrinkage of the rock as it cooled down from the temperature of solidification to the normal temperature of the ground. If this is the true explanation the columns are examples of prismatic jointing caused by contraction in the act of cooling. The beach sand fashioned by the ebb and flow of the waves of an ancient sea, lately brought to light in the midst of our green hills and valleys, and the colonnades in High- land Park, flanking " Rocky Mountain," force the mind backward unnumbered ages, though it never wearies on the unending trail. The columns in flowing sand revealed by the spirits of air may never again be seen by the eye of man, but they have been preserved by the spirits of light to attest their existence. Shall it be by such means only that the future will know of the remarkable columns now existing in High- land Park ? The people of Greenfield'will do well to follow the lead of Mr. Barney N. Farren — that public benefactor on whose head may blessings fall— and see to it that the hand of the destroyer, now stayed, shall ne\'er again be raised to mar this wonderful revelation in the life history of our grand, old earth. 0- J J o z o o < z o H u w w < iigi^ z^^:^^- iv^^-^,)' t^ ::^-' -Jf^ v-'^- ':* • ■ ^ ' '^f fe'i^'^'ili < 1^ ■n O u Q ?; 6 ' h 'f V)U''Jf*II . 1 J/ '11- •■( , i,M), WW ^■Ci*» >-^ > < IV ^ .:;- iivw'"- '^1; I'm*- ■■-■ ^ »* y vr^T/'i CO J ■r. PLATK VII. CUR\'ED COLUMNS AT HOSMER'S PEAK, PLATK VI II. ^ «^-<'.te s:^; r?--'"- :^^:^^*«^ COUMNAK TRAP IN HIGHLAND I'ARK. PLATE IX. COLUMNAR TRAP IN HIGHLAND PARK. PLATE X. S^ AN OLD EXPOSURE. y. ■r. y. ■A y < < < y. ""W •JO ^^jy»f, . ^ rj^ / f (K I. y .►^«^:*?i?l - u < < ■r. ^■* 'l^Jtl.'W W !