Chapter II: Front Matter (2)

Hot springs the world over register their presence by leaving deposits of unusual minerals, and they have left this sort of record at Loudville. Here the coarse sandstones of the lowland rest upon gneiss, and at the south end of the Loudville lead vein barium sulphate crystals, called barite, formed in the sand before it was cemented into solid rock. The crystals are the product of highly charged mineral water, rising through the sands from a subjacent fissure. The fissure itself is also filled with barite, and with galena and quartz as well. It is the vein which was worked in the old Loudville lead mine. There are other veins in the western and eastern highlands at Hatfield, at the Northampton reservoir near Whately, and at Leverett. All are in fractures which were still partly open when the valley first took form.

_The Marginal Uplands_

The rocks which formed the high eastern mountain range of Triassic time and the rocks which made the old western hills and underlay the basin floor comprise essentially a single group characterized by its complexity. At one place the rock resembles sandstone, but the layers stand on end; at another, it looks like shale, but the stone breaks across the color banding instead of parallel to it; and at a third place a fissure seems to have opened and had a crystallizing melt poured into it. These tabular, filled fissures can be found nearly everywhere, coursing in every direction and at all conceivable inclinations to form a network that binds the older rocks into a firmly knit whole. The fillings, or dikes, are like reinforcing rods, holding the rocks together and withstanding the agents of destruction. Thus, the story of the highlands has three distinctive phases,--a relatively young phase when the interlacing reinforcements were poured into fractures; a somewhat more remote stage, when the bedded rocks were crumpled into their inclined positions; and an earlier stage, when the bedded rocks were deposited. The geologic dates of these three events may vary from one locality to another, and they certainly are different in the Eastern Upland as compared with the Western Upland; but the events always occurred in this sequence and constitute the broader aspects of the story at all places.

_The Eastern Upland_

The Eastern Upland includes the land between the Connecticut Valley and the Atlantic Ocean. At present, it has the general form of a broad rolling highland with ridges and valleys that have a north-south trend. Close inspection shows that the rocks in the ridges are different from those in the long valleys. Also the layering of the materials ranges from a vertical attitude, as at Ware and Brimfield, to undulating and almost horizontal positions, as at Spencer and Worcester.

Through vertical and horizontal beds alike run those reinforcing sheets--some tabular and vertical, called dikes; others also tabular but horizontal, called sills; and some are just huge, irregular masses without visible bottoms, called stocks and batholiths. Some of them, composed of uniform, small, light-colored minerals, are granite; others are made entirely of large minerals over an inch across and are called pegmatite; a few, with cuneiform intergrowths of a dark mineral in a light one, arranged like Arabic writing, are known as graphic granite.

Pl. 5. _Intrusive and extrusive igneous rocks._

Every one of these masses flowed into the rocks along fractures and other zones of weakness, crystallizing as they lost their heat and solvents to the hot springs of that ancient time. They are all invaders, or intrusives, which inserted themselves into the older beds. Whether they were squeezed into the fissures by the pressures that crumpled the original beds into their upturned positions, or whether they, like the liquid in a hydraulic press, transferred pressure from a deep reservoir to the walls of the fissures and so pushed the beds into their distorted forms, is unknown. Two features are clear; the distortion of the beds and intrusion of the liquid bodies were almost simultaneous, and the hot springs associated with them were still active at the dawn of Triassic time. These profound disturbances transformed the land into a series of elevated, wave-like folds, and rains promptly began to tear away at the summits of the newly raised mountains. From them was carved a serrate and rugged landscape, part of which was later buried beneath the Triassic fill.

_Coal Swamps in Massachusetts and Rhode Island_

Among the strata of the Eastern Upland which were folded, intruded, baked hard, and stewed in hot spring water, one group stands pre-eminent. It forms a broad band starting north of Worcester and reaching to Providence and beyond. Nearly everywhere it carries coaly material or impressions of plants which are now extinct, but which flourished in the Coal Age or Carboniferous period. Some of the coal seams were mined in the Providence basin, but they had been so heated by intrusive granite that they are partly graphitic and proved difficult to burn. The great extent of some of the coal seams suggests a panorama of immense swamps, and of land so flat that, for long periods, streams brought no sediment, and the trees and water-loving plants furnished the only fill. At other times sluggish rivers, flowing from the northwest, laid thick layers of sandy mud over the surface of the bogs. The alternating muds and coal seams are thousands of feet thick, and they record the story of a basin which sank as fast as it filled--a depression which was never built high enough to be a well drained plain, yet never subsided sufficiently to be inundated by the sea. The Carboniferous peat bogs and mud flats may have extended westward almost to the Connecticut Valley; and farther to the northwest they were bounded by a chain of rolling hills.

The rock floor of the coal basin contains a variety of ancient materials. Some rocks were river deposits, some were marine limestones, a few were lava and volcanic ash, and many were granite and gneiss which crystallized at great depths and became exposed only after streams had stripped away the thick overburden. The basin floor thus holds a complex story, in which land and sea, vulcanism and quiet, erosion and deposition, all played their respective roles. Only in the west, along the margin of the Connecticut Valley, is the involved story at all clear. And in the Western Upland across the red-rock inlay, it is possible to see some of the land as it was before trees took root in the swamps, and rivers brought sands and muds from the vegetated hills that hemmed in the coal basin.

_The Western Upland_

Many years ago, when transportation facilities were not what they are now, New England settlers mined iron ore from the hill north of Bernardston and smelted it in local charcoal furnaces. The rocks containing the iron are creased into sharp, close folds, and they came into such close contact with a hot granite intrusive that their minerals were changed by its action. This granite, however, is older than the one which is associated with the disturbed Carboniferous beds, for it was intruded when the Devonian sediments from Gaspé to Connecticut were deformed. It was this profound disturbance that turned the red rocks of Roche Percé from a horizontal to a vertical position and raised a mountain range which stretched through all of northern New Brunswick, Maine, the lowland section of New Hampshire, and a belt extending for some miles east and west of the Connecticut Valley. The eroded remnants of these Shickshock Mountains formed the backdrop for the great Carboniferous coal swamps in Rhode Island, Massachusetts, and Acadia.

The iron ore was a hot spring replacement of a limestone containing shells of sea organisms which lived when chordate animals first became abundant. This was the Devonian period in geologic history--the time when a backbone appeared essential in every really high-grade animal. The limestone rests upon a beach gravel, now consolidated into a quartzite conglomerate. The gravel consisted of small white quartz pebbles which came from the many veins in the steeply inclined slates of the adjacent coast.

Marine deposits of Devonian age are found as far south as Leverett, and scattered outcrops indicate that the old seaway reached northward up the Connecticut, entering Canada east of Lake Memphremagog. Thence it spread eastward to Gaspé and westward to Montreal, and around the north and west side of the Adirondack Mountains into New York State. A low rolling land where the Green Mountains stand today formed the western shore of the Devonian sea for many miles northward into Quebec. The Adirondack and Taconic Mountains were a fused aggregate of undulating uplands which limited the seaway on the south along the International Boundary. Its eastern shore lay far beyond the horizon of the region described in this brief account.

The rocks of the old Devonian coast in Massachusetts were chiefly slates, cut by many quartz veins. They are exposed along the Mohawk Trail in the ascent from Greenfield to Shelburne Summit, and they continue northward in an almost unbroken band through Bernardston, Brattleboro, and Northfield (Vermont) to Lake Memphremagog. They contain casts of planktonic life which inhabited the Ordovician seas in these northern latitudes, and the Ordovician strata, together with still older Cambrian sediments found below them, meet the Devonian beach deposits at a sharp angle, just as the slates along the coast of Maine meet the modern beach sands and gravels. Like the slates of Maine, they were eroded deeply before the beach existed, and their slaty structure and their steeply inclined attitudes were acquired in a still more ancient epoch of deformation.

The folded rocks of Ordovician age flanked the highland area which now constitutes the axis of the Green Mountains. West of the Green Mountains they make the Taconic Range, and to the east they appear in ranges that go under a variety of names, including the Northfield and the Lowell Mountains. In the Taconics the folds have the shape of waves advancing westward from the center of disturbance in the Green Mountain axis; within the Connecticut basin the Ordovician folds have wave-fronts which advance from the same axis eastward across the Memphremagog sea. Along the eastern margin of the old land a series of dark green intrusives called peridotite welled up from the depths of the earth, and they now cut through the rocks extending from Chester, Massachusetts, to Thetford Mines, Quebec; they are like giant boundary posts marking the ancient line of demarcation between sea and land in Cambro-Ordovician time.

Originally the folded strata in the Taconic region were deposited in clear marine waters, where calcium carbonate accumulated rapidly. But the sediments of the same age east of the Green Mountain land represent an unbroken succession of hardened muds, which rest on sandy muds, and on fine and coarse products of violent volcanic eruptions--tuffs and agglomerates--and lava flows. No lime-secreting animals could thrive in this sea, although they numbered billions in the western waters; for only floating plankton could escape the interminable mud, and they drifted up and down the coast from Quebec to Connecticut. One or two straits may have connected the clear waters of the west with the muddy waters of the east, for some of the planktonic organisms have been found in the muddier sediments of the westerly waterbody.

The Cambro-Ordovician sea lapped even older rocks, contorted and cut by intrusives which bonded them precisely as much younger invading liquid rock bonded the younger sediments of the Eastern and Western Uplands. The older rocks were also laid in a sea--a sea so much more ancient than the Cambrian and Ordovician seaways that its shoreline and even its form and extent are at best conjectural. And when we study these oldest marine beds, we find that their ingredients were in part derived from still more ancient sedimentary rocks, which accumulated in the sea, and that these old beds were elevated into the land that supplied the waste now found in the oldest coherent section of rocks in western New England. Indeed, the dawn of the Cambrian period, when life first became abundant, was merely a half-way mark through geologic time. Although half a billion years have elapsed from the Cambrian to the present, another half a billion years reach still farther back towards the beginnings of earth history, beyond which science has not yet peered successfully. These billion years are but a finite segment of history, bounded by the infinite past and the infinity of the future.

It seems appropriate, therefore, to end our journey down the fourth dimension at this point, and as we retrace our steps, we can profitably survey the chronologic succession of events and scenes which followed each other from Cambrian time to the Twentieth Century A.D.

The Story of Central Massachusetts

The protracted story of central Massachusetts might be that of many another section of eastern North America, except for minor details. In Cambrian time an inland sea, well stocked with simple marine organisms, washed the shores of an archipelago which extended north and south through the Berkshire Hills, the Green Mountains, and the Notre Dame Mountains. Composed of rocks which themselves had had a long and involved geological past, the islands rose intermittently as streams and waves wore them away. Clear water and sandy beaches stretched along their western shore, and the original Adirondack Mountains were just visible from the summits of the higher islands. Swift streams raced down their eastern slopes, carrying gravels, sands, and silts into the eastern arm of the sea, and only free-swimming animals could survive in its turbid waters. For a time, volcanoes erupted and fumed along the entire eastern coast from Thetford Mines, Quebec, to Plainfield, Massachusetts, but their activity was short-lived. Only the streams which drained the broad islands endured, and they never ceased to pour mud into the eastern ocean. Gaps in the island chain permitted some of the free-swimming organisms to migrate to the western sea, where bottom-living plants and animals were actively secreting the limy shells and skeletons which helped build thick deposits of Cambrian limestone.

These conditions continued into the ensuing Ordovician period of geologic time, but gradually the situation changed. Again the volcanoes renewed their activity, and masses of dark peridotite were intruded along the eastern shore; the island chain rose rapidly, and the straits closed. The elevated land began to expand outward, and folds spread eastward on the east and westward on the west, like waves from a center of disturbance. So great was the pressure that portions of the old land were sheared outward over the folded sediments. The Taconic disturbance was on from the city of Quebec to the city of Washington; and the streams, like ants, kept at their endless task of carrying sand and gravel into any and every depression they could find. They piled up great thicknesses of Silurian sandstone in Maine and New York, and so effectively did they tear down the Taconic Mountains that the Silurian sea was ultimately able to penetrate the region from Thetford Mines, Quebec, almost to White River Junction on the Connecticut River.

One period later a Devonian sea followed in the wake of the Silurian sea, but its waters penetrated even farther south to Leverett, Massachusetts. The quartz gravels of its advancing beach covered the worn flanks of the Taconic folds. Sea animals left their shells to form a bed of limestone which may be seen today at Bernardston. But again the sea was shouldered aside by the restive land, which rose from Gaspé to Virginia. Much of the region affected by the Taconic disturbance was elevated again, and a broad band of Devonian sediments was folded closely through northern New Brunswick, southern Quebec, northern Maine, northern and central New Hampshire, and central Massachusetts. Granites welled up into the sediments, and dikes filled all the fissures. The baking, stewing, and reinforcing they gave to the older sediments made them so firm that they are still one of the most coherent and resistant series of rocks in New England and maritime Canada. This was the Shickshock or Acadian disturbance. Meanwhile the first forests took root on the long piedmont plains that spread from the rising mountains westward into the Catskill Plateau of New York State (Catskill sandstone) and eastward to the coast of Maine (Perry formation).

The margins of the piedmont plain sank. Vast, luxuriant swamps succeeded the old forests in Pennsylvania on the western piedmont, and in Rhode Island, Massachusetts, and Acadia on the eastern piedmont. The swamp vegetation later became the coal seams of eastern North America, and well does this time merit its name--the Carboniferous period. The Shickshock Mountains remained in the hinterland forming highlands from Spencer, Massachusetts, westward into New York State; but they were shorn of their crags, and only on rare occasions were the streams swift enough to carry silt into the swamps and to bury the accumulated peat.

Torn and twisted as New England had been by the two previous disturbances, it was to suffer yet again. The entire northern section of the eastern coal swamps began to rise, and the movement spread southward through New Jersey, eastern Pennsylvania, Maryland, Virginia, the Carolinas, and Georgia. Granites insinuated themselves once more into fissures in the elevated landmass; the rocks were pushed outward from the raised block; and the sediments of the coal fields were thrown into folds which diminished in magnitude towards Ohio on one side and Cape Breton Island on the other. This was the Appalachian Revolution. When it was over, even the youngest sediments were interlaced with granite sheets and dikes; they were cooked hard in hot spring waters; and they were crumpled into close, long north-south folds. The landscape was changed completely: mountains had replaced the peat swamps; and from their summits alpine glaciers were plucking rock fragments which they dumped into the Boston basin. Streams, too, cut deeply into the mountainous upland, but there were no other local basins in which the fluvial debris could come to rest.

This was, in brief, the course of events which transpired in that era of geologic time called the Paleozoic. Twice as long as all ensuing time, the era was one of kaleidoscopic change, with placid seas, eruptive volcanoes, swift streams, and towering mountains competing for the lead roles in three rather similar historical cycles. When the Paleozoic era was over, the matrix of tough, resistant rocks was ready for the delicate inlaid design which was imposed upon it in the Triassic period.

There was nothing tranquil about Triassic time. While hot springs, born in the cooling granites, still oozed from rents in the mountainsides, a tremendous 100-mile-long rift tore through the east margin of the old Shickshock Mountain foundation. The rift was a clean break at some places, but elsewhere it was splintered and offset. Each northern sector of the break invariably ended west of the beginning of a southern one, and the intervening rock is characterized by multiple fissures with more or less displacement of their walls.

The block east of the rift moved south and rose, while that to the west was depressed into a tilted and asymmetric basin. Mountain streams flowing eastward to the Atlantic were caught at the base of the rift, and a new set of torrents dashed down the west-facing scarp of the elevated block. After every cloudburst these new streams left their contributions of boulders in screes along the east side of the basin. The gravels steadily increased in thickness, covering the hills and valleys that furrowed the lowland floor. Much of the ancient relief still lies buried beneath the fill, but some of the eminences were exhumed one hundred and fifty million years later and have received man-given names like Mount Warner and Bernardston Ridge. As the basin subsided vertically for more than a mile, the mountain streams spread fans westward across most of its floor, restricting the contributions of the western rivers to a zone which is now less than two miles wide. The largest of the eastern rivers wore a valley three miles wide where it entered the lowland northeast of Granby.

Then volcanoes broke loose in the basin floor. Lava oozed through the sand west of the Notch in the Holyoke Range, and it frothed out of the openings or was blown violently from them. But by sheer persistence the rivers still dominated the scene as volcanic activity waxed and waned, and 1,500 feet of alluvial wash piled up around the volcanic cones. The energy of the volcanoes was ultimately spent, but for some time lava poured out of craters along a line extending southward from the main eruptive center, and from a second center which approximates the course of the Connecticut River from Sunderland to Turners Falls. It flowed westward into the middle of the basin in a series of sheets until it was 400 feet deep; it pressed upward against the sand plains along the western hills; it surged east up the fan slopes where it ended in a frothy wall; and it spread southward from these two centers and from others to New Haven. The lava, now tilted, gives substance to the Greenfield Ridge, the Mount Holyoke and Mount Tom Ranges, and the long line of hills that pass through Hartford and Meriden.

Spectacular was this outburst in its time, and profound was its influence upon later scenery, but short was its duration. Before weather could redden the lava surface, streams washed gravel over it; and only at the main centers between the Mount Holyoke Hotel and the Amherst-South Hadley road were the volcanoes able to hold out against the relentless activity of running water.

The block east of the rift continued to move southward and to rise, while the streams draining it entrenched themselves in an effort to remain at grade with the basin floor. The moving mountain mass pushed the lava flow up on end and twisted its eastern edge around, dragging it along to the south. The rock splinters which were formed in the process sliced the basin sediments into small blocks, some of which can be seen north of Turners Falls and also at the Holyoke Range. Ultimately the upward and southwestward movement along the rift piled the eastern blocks against the more westerly ones, pushing the west side of each eastern block up on the east side of the adjacent western one, and depressing its eastern side more deeply into the basin floor. The many fractures which were made weakened the basalt lava sheet along certain zones where, in recent time, the elements have worn the notches in the Holyoke Range.

Streams from the eastern highland stubbornly filled up the holes and planed off the raised blocks during the entire period of intermittent movement. In the midst of the tussle between earth forces and fluvial agents the volcanoes again broke into explosive eruptions, and volcanic ash filled many of the block-like depressions all the way from Granby to localities south of Holyoke. Then the fiery vents cooled, and the earth movements diminished in their vigor. But they left a mountain front so steep that talus and landslide deposits accumulated at its base near Mount Toby; and the block mountain range was so high that glaciers may have wreathed its summit. The mountain mass descended southward, and it was penetrated by at least one low pass northeast of Granby.

In the basin itself, alluvial fans encroached from the eastern mountain front, but out in the middle of the valley ephemeral playas and shifting lakes were numerous. Rushes fringed the lake shores; fish stocked their waters; and dinosaurs lumbered over the adjacent flats. The region was one of violent rains and seasonal droughts, of hot days and frosty nights--a semi-desert country lying in the lee of the Appalachian ranges, somewhat as the intermontane valleys of the West lie in the rain shadow of bordering mountains. Eight thousand feet of sediments poured into the Triassic trough while these conditions lasted, but the situation altered slowly as the Jurassic period dawned.

Throughout earth history, vulcanism and mountain-making have been spasmodic events; but so long as rain has fallen and water has run downhill to the sea, the unspectacular rivers have never relinquished their task of reducing the lands to the lowest grade on which water will flow. During all of the Jurassic and Cretaceous periods, and even into the Eocene epoch of the Tertiary, New England's rivers worked towards this end, and they came as close to attaining their goal as the restless earth has ever permitted them to do. The region from the Atlantic to the bases of the Green Mountains and the White Mountains was reduced to a broad, faintly terraced erosional plain. Not all of it was leveled, for Mount Wachusett, Mount Monadnock, the summits of Mount Greylock and Mount Ascutney resisted the wear and tear of the weather and of running water, and retained some of their original stature. At the headwaters of the streams the Green Mountain chain and the White Mountains also withstood reduction to the common level, forming the divide between St. Lawrence and Atlantic drainage. Such rivers as the Merrimack, the West, the Deerfield, and the Farmington followed somewhat different courses than they do today, for some of the drainage heading in the Western Upland of New England flowed straight across the red-rock valley to the sea.

During Tertiary time the entire region rose vertically as a unit. The rise was intermittent, punctuated by long stillstands of the upland with respect to the sea. One of the earlier uplifts carried the land some 200 feet higher; and although the rivers maintained their courses, they deepened their valleys and ultimately widened them into broad, open plains far back towards their headwater reaches. In the resistant rocks on either side of the red-rock basin the valleys were sharp and well defined, but in the soft Triassic sediments the rivers cut wide swaths, nearly eliminating the low divides which kept them in their independent courses.

In Middle Tertiary time renewed uplifts occurred, and ultimately the strathed surface was elevated 1,800 feet inland at the Green Mountain divide. Once more the rivers started busily cutting down; but in a protracted stillstand, while the New England upland still lacked 700 feet of its present elevation, the Atlantic Ocean planed off the hills in southern Connecticut as far north as Middletown, and the Farmington River adopted a more direct route across the marine plain to the sea. Before the West, Deerfield, and Westfield Rivers could lower their channels to grade in the reinforced rocks of the Eastern Upland, a tributary of the Farmington worked headward along the poorly consolidated red rocks of the basin and diverted the waters of the northern streams into its own channel. This was the birth of the Connecticut River, and in late Tertiary time, the energies of the new-born stream were effectively expended widening the whole of the Triassic basin. Even some of its larger tributaries developed wide valley floors with steep walls in the hard crystalline rocks of the uplands. Only the lava flows and the buried old-rock mountains withstood planation in the red-rock basin. The flows form such trap ridges as Greenfield Ridge, the Mount Holyoke Range, the Mount Tom Range, the Hanging Hills of Meriden. Exhumed mountains are typified by Mount Warner.

All of northeastern North America was raised to great heights in late Pliocene time, and the Atlantic Ocean withdrew at least fifty miles southeastward from the present shoreline. The rejuvenated rivers deepened their valleys, forming narrow, sharply incised canyons like the gorges of the Hudson and the Saguenay; and the Connecticut made a deep groove in the lowland floor, cutting to depths which have been partly disclosed by drilling at the Calvin Coolidge Memorial Bridge and the Sunderland Bridge.

While the land stood in this high position, one winter's snow in the White Mountains failed to melt before the next began to fall. Snowfall accumulated upon snowfall, covering not only the White Mountains, but all of Canada and New England; and the Ice Age was here to stay more or less continuously for a million years. The ice piled up against the highest mountains and ultimately rose so far above them that it slid over their tops without attempting to detour around them. Its surface may have been 13,000 feet above sea level in northern New Hampshire, and its surface slope, which is estimated at 150 feet per mile, would give a thickness of 10,000 feet at Northampton. The continent yielded slowly under this great load, and it sank until all of the elevation gained in the Pliocene movement was wiped out, and more besides. The ice radiated from the centers of maximum accumulation--at first from the White Mountains, and then from northern Ontario, and finally from Labrador. The continental glacier crept southward to Long Island and Martha's Vineyard, where its front melted in the waters of the Atlantic as fast as new ice came up behind. It dragged and pushed and carried debris, only to dump it in a hummocky ridge, like a rampart, to mark its farthest advance.

At last the glaciers started to melt even faster than new masses moved down from the north, and the ice front began to recede 400 to 700 feet per year. The sea followed it, up the Hudson, up the St. Lawrence, in over the coastal lowlands for a short distance; and everywhere pounding waves made beaches at the water line. And in the path of its slow, deliberate retreat, the glacier left rock debris--boulders on the hills and in the valleys, boulders everywhere; all the landscape was marred and desolate.

The ice had weighed the pre-glacial valleys down more deeply in the north than in the south. One such valley was the Connecticut Lowland, in which water gathered to overflow-height at Middletown. Thus Lake Springfield came into being, and it spread northward as the ice front receded. North of the Holyoke Range another lake formed, and this northern body of water has been named Lake Hadley. Streams flowed off the ice, off the hills--flowed with unimpeded vigor, for there were no trees or grass to retard the run-off. Deltas grew out from the shores, and annual layers of clay settled on the lake bed.

The ice grew thinner, its area smaller, and its load lighter; and as Mother Earth lost her heavy burden, the land rose, more in the north than in the south. The differential rise decanted the water southward out of the lake basins, and the seas retired from the coastal lowlands. Old shores and sea beaches remained as flat terraces sloping gently southward. The rivers raced down the steep beach slopes to the old lake floors and sea bottom. They cut their channels deeply into the unconsolidated deltas and meandered back and forth over the flat, ungraded lacustrine plains, as if uncertain where to flow. They flooded the lands in the spring, leaving loose sand and silt for the winds to blow when the water was low. Sand dunes rose near the river banks at North Hadley, Sunderland, Hatfield, and South Deerfield; but the march of the dunes was arrested as post-glacial vegetation repossessed the land. It was at this point in the story that man found and settled the Connecticut Valley, becoming a witness to the geologic work of the river and an aid to the work of the wind as his plow bared the fertile soil to the elements.

Interesting Places

Books and periodicals supply dinner menus for the hostess and list theatrical offerings for the habitué. Surely suggestions of places for a picnic or an evening drive are equally in order. Experience, some of it painful, soon reduces the number of pleasant picnic sites: poison ivy or a deceptive bog may linger in the memory and automatically eliminate some otherwise delightful spot. But places suitable to every taste lie within the Connecticut Valley or along its fringing uplands. Some are near the highways and others are on woodland trails; a few are interesting for their immediate surroundings and many because of their expansive view. Here is a landscape which can be appreciated without leaving or stopping the car; but there is a sight which can be relished only from a trail, or from a pinnacle accessible to the agile climber. Drives satisfy some tastes; but places to stop, meditate, and conjure up the past appeal to others. The Valley and its environs have something for every temperament and every mood.

_Mount Lincoln in Pelham_

Mount Lincoln is remote enough from highways to offer some measure of retreat, yet it is not discouragingly inaccessible. The summit rises about 300 feet above the nearest road, which lies a mile away by woodland trail. It is Pelham's highest eminence, and its height is enhanced by a fire tower which affords a magnificent view in every compass direction.

The gently undulating New England upland stretches off to the north and east for miles. The innumerable hills which compose it integrate to form a horizontal skyline, which suggests a flat erosional plane, originally formed at, or near, the level of the sea. To the northeast Mount Monadnock in New Hampshire rises prominently above the general level, for its extremely resistant rock withstood reduction by weather and water more effectively than the weaker bedrock on every side.

The valley lowland begins but three miles to the southwest. The range of hills stretching away like beads on a string is the Holyoke Range. Mount Toby, Mount Sugarloaf, and the Pocumtuck Hills are the prominences in the lowland to the northwest. The lowland was eroded out of the New England upland after the land was elevated far back in Tertiary time, and the disintegrating rock was carried to the sea by the rivers. The hills in the lowland were left where the rocks resisted destruction more successfully than elsewhere, but they only approximate the level of the upland of which they were once a part.

Mount Lincoln and the surrounding hills are strewn with boulders. Every slope is dotted with large irregularly shaped rocks, many of which have smoothed facets marred by minute scratches. The boulders were left by the Great Ice Sheet when it melted off New England, and the scratches were made when the ice dragged the boulders over hard rock surfaces. These stones came down from the north, and among them you may recognize types which you have seen in the ledges around Orange and Northfield. Early Pelham settlers found the boulders as much in their way as the trees; so they burned or used the trees, and they piled the stones in long rows to fence their fields. Stone fences characterize all glaciated regions, and here they follow the roadsides for miles, reaching to the edge of the deposits in glacial Lake Hadley.

_Mount Toby_

"Let's go to Mount Toby" usually means to go to the camp ground along Roaring Brook at the east base of the mountain, or to one of the sugar camps on the west slope, or to the Sunderland Caves at the north end. All of these places are worth knowing, but the view from the mountain top deserves at least one trip, and the wood road from Roaring Brook is replete with interesting sights.

1. Davis pyrite mine
2. Plainfield manganese mine
3. Lithia spodumene pegmatite
4. Chesterfield tourmaline locality
5. Westfield marble quarry
6. Williamsburg galena vein
7. Hatfield lead mine
8. West Farms lead mine
9. Loudville lead mine
10. Westfield trap quarry
11. Bernardston magnetite mine
12. Gill dinosaur track quarry
13. Mount Toby
14. Sunderland Caves
15. Roaring brook
16. Whittemore's Ferry fish quarry
17. Mt. Sugarloaf
18. Leverett lead vein
19. Notch quarry
20. Northampton granite quarry
21. Titan's Piazza
22. Titan's Pier
23. Ox-bow lake
24. Smith's ferry dinosaur tracks
25. Varved clay pits
26. Mt. Grace
27. French King bridge
28. Mt. Lincoln
29. Pelham asbestos mine

The side road to Roaring Brook leaves the highway east of Mount Toby just north of the old cemetery, and the camp site is on the west side of the Central Vermont Railway tracks. The gray rocks east of the tracks are part of the ancient mountains of Triassic time. Their lofty summits have been worn away by the unceasing activity of weather and running water, and they are now lower than the fans of waste which was discharged from the ancient valleys. Roaring Brook is continuing the work of erosion as it tumbles down from Mount Toby, and frost has loosened the great boulders that lie on the mountainside.

The rock along Roaring Brook is very different from that east of the railroad. It looks a great deal like concrete, with a large assortment of aggregate materials mixed in with the cement. The rock is conglomerate, a mass of coarse stones washed out of the ancient Triassic mountains, deposited at their base and in contemporary stream valleys, and then cemented during the ensuing ages. Many of the pebbles in the conglomerate cannot be found in the old rocks east of the railroad tracks. Actually these rocks change in character at different levels in the uplands of today, and still higher changes which were present in this mountain group during Triassic time have been destroyed, though the record of their presence has been retained in the fragments which compose the conglomerate.

The woodland trail starts up the mountain about 100 yards north of the picnic grounds. The rock beside it is red granite, and the streams of Triassic time flowed over it as they carried the gravel which now makes the Mount Toby conglomerate. The latter first appears about 100 feet uphill, and it is virtually the only rock exposed from this point to the summit. Interspersed sandstone beds disintegrate easily and form quiet pools and basins in the adjacent brook; the pools end a few feet upstream where the water cascades over the edge of the next higher conglomerate stratum.

Mount Toby's summit rises above any other eminence in central Massachusetts east of Ashfield and south of Mount Grace near Northfield. From it the entire country to the south appears low and flat, except for the teeth of the Mount Holyoke Range and the long ridge extending southward from Mount Tom. A slope rises westward from the lowland to meet the edge of the flat New England upland along a line that passes through Shelburne, Conway, Goshen, and Granville. East of Toby this same upland comes so close that it seems but a step across to it.

Many peaks may be seen rising above the New England upland. The one far to the east is Wachusett. Up there to the north-northeast are Monadnock and Mount Grace. Over in the northwest are Stratton and Glastenbury in Vermont, and much nearer and lower is Bald Mountain at Shelburne Falls. Mount Greylock, the highest point in Massachusetts, is almost due west.

The lowland was excavated after the New England upland was elevated, and the main features which distinguish the present landscape were carved out before the end of the Miocene epoch of Tertiary time. The high points which surmount the upland are monadnocks which, like their prototype Mount Monadnock, successfully resisted the ravages of time and New England's changing but rigorous climate.

_The Sunderland Caves_

The Sunderland Caves are on the northwest side of Mount Toby, just a short walk and an easy climb from State Highway 63. They penetrate a cliff made of conglomerate overlying a shale which accumulated in a Triassic lake. The shale makes the floor of the cave. Joints, forming a right angle with the cliff, break the conglomerate into giant blocks. Frost, smooth shale surfaces, and gravity have caused the two end pieces to creep away from the other conglomerate blocks. The second block from the end has fallen against the end block, forming a high-roofed cave about 100 feet long.

Directly southwest of the lower entrance to the cave, the shale beds are highly distorted along the borders of a trough-like mass of angular conglomerate or breccia, in which boulders up to six feet in diameter are numerous. It is believed to be the record of a Triassic landslide, which avalanched down the mountain front immediately to the east, and into the old lake at the mountain base. It plowed up the clays in the lake bed, carried some of them away, and furrowed the others into the crumpled forms that are clearly visible along the path to the caves.

_Mount Sugarloaf_

Mount Sugarloaf does not offer Mount Lincoln's retreat from crowds nor Mount Toby's expansive landscape, but it is accessible, and it provides an unrivaled view of the valley between South Deerfield and the Holyoke Range. Its red sandstones and conglomerates rise almost sheer for 500 feet above the Sunderland-South Deerfield road. On the northwest and southeast sides the cliffs are determined by nearly vertical joint planes. During the Ice Age, the southward-moving glacier plucked away the loosely attached blocks facing the South Deerfield and Sunderland sections of the lowland, leaving Sugarloaf as a remnant between the joint surfaces.

The great bites which the meandering Connecticut River has taken out of the lowland are visible east of Sunderland village and south towards Hatfield. Each arc in the edge of the scalloped flood plain is the extremity of a meander loop which the wandering river carved in its bank and then abandoned by breaking through the narrow base or tongue, as it did at the Northampton ox-bow.

An area of low, rolling, sandy hills extends through the pine woods for a mile southward from South Deerfield. The hills are dunes which formed when the Connecticut was picking its channel across the newly exposed and barren bed of glacial Lake Hadley.

The panorama from the west side of Mount Sugarloaf centers about the deep gorge of the Deerfield River. The top of the gorge widens out into a broad strath and affords a glimpse of the more remote upland. The river, emerging from this canyon during post-glacial time, built a huge delta into glacial Lake Hadley, and much of the delta still remains in the terrace which is utilized by the Boston and Maine Railroad as it descends into Greenfield.

_Turners Falls_

Rushing water has a fascination which was frankly recognized by the highway engineers who made the parking place facing the Connecticut where Route 2 passes along the north side of Turners Falls. Here the river drops over a series of sandstone ledges into a deep and narrow channel at the east base of the trap ridge. Waterfalls are not common in rivers flowing through lowlands; they indicate disturbances of normal stream development and sometimes change in course.

The Connecticut Lowland is old, but its ancient drainage lines were buried by the deposits left in glacial Lake Hadley. The river's present course was established upon these lacustrine sediments, and the inner valley plain is excavated in them. Before entrenchment took place, the south-flowing reach of the river above Millers Falls was deflected westward across the lake plain by the delta of Millers River. It was turned southward once again by the trap ridge near Turners Falls. The river soon cut through the unconsolidated lake beds and found that it was out of its pre-glacial channel. The delta of Millers River had diverted the water from the old rock valley beneath the Montague sand plain, across a rock divide, and into the pre-glacial valley of Falls River. The lake-fill in Falls River has been almost completely removed, and Turners Falls now mark the spot where the Connecticut pours over the bank and into the channel of its pre-glacial tributary. The falls have receded upstream several hundred feet and have cut a deep gash in the Triassic rocks.

Pl. 7. _Gorges, in highland and lowland alike, were formed when the
rivers were superimposed on coherent rock._

Turners Falls are the product of a series of coincidences. First, the ice sheet and Lake Hadley buried all established drainage lines and forced the streams to adopt new routes over the bared lake bottom. While the lake existed, Millers River threw a weak obstruction in the path of the Connecticut, diverting it to that part of the lowland where one of its pre-glacial tributaries had excavated a slender rock gorge along a fault plane. The river washed the lake deposits out of the gorge, exposed the old bank of Falls River, and was busily cutting a new gorge back into this bank when the dam was constructed and its erosive activities were suddenly arrested.

_The French King Bridge_

The highway from Greenfield to Athol and Fitchburg passes Turners Falls and crosses the Connecticut River near Millers Falls by way of the French King Bridge. Here the roadway is more than 130 feet above the water level. A picnic ground and parking place at the west end of the bridge make it a particularly attractive place to stop and enjoy the view upstream towards Northfield.

The river occupies a narrow rock gorge for a mile north of the bridge, but at that point the valley widens out. This entire section of the river's course was established on the old bed of glacial Lake Hadley; but after the unconsolidated deposits were washed away, the stream found itself flowing along the weak contact between the Triassic conglomerate on the west bank and the metamorphic rocks of the highlands on the east bank. The river deepened its channel on the weak contact zone and made the scenic cut over which the bridge was built.

The pre-glacial valley lies beneath the sand plain east of the river. Millers River crosses this old valley between Millers Falls and its confluence with the Connecticut, at the east end of the bridge. The rapids at the junction can be traced to the ridge of crystalline rock between the east bank of the present Connecticut and the west bank of the pre-glacial Connecticut. The resistant ledge forms a barrier which Millers River has not yet eroded to its grade.

The conglomerate beds on the west wall of the gorge dip steeply eastward towards the river and end against the crystallines. The beds were originally laid down with a gentle westward inclination. They were tilted steeply in the opposite direction against the crystallines by faulting, which elevated the ranges and pressed down the adjacent basin during Triassic time.

_Titan's Piazza and Titan's Pier_

Not so long ago, giants and the devil received the credit or the blame for such oddities in nature as rock-masses broken into six-sided columns. Ireland has its Giant's Causeway, and Yellowstone National Park its Devil's Post-pile. Titan's Piazza and Titan's Pier were likewise attributed to activities of the leader of fallen angels and were given names appropriate to such an origin by the early settlers. Dr. Hitchcock, in characteristic fashion, undertook the task of correcting the errors of puritanical psychology by renaming these places during one of the early Mountain Day trips from Amherst College. The entire college body sojourned to the west end of the Holyoke Range to hear the cliffs renamed and their true nature explained.

Devil or no devil, those huge columns had a hot origin. The dark rock in them is part of the main lava sheet which stretches across the valley in the Holyoke Range and swings southward in the Nonotuck--Mount Tom Range. The lava poured out of a series of volcanoes which were strung out along a fissure about three miles to the east, and the molten mass had a temperature of 1200° to 1300° C. The hot lava radiated its heat to the sandstone below and to the air above; and, as it cooled, it contracted like any other substance. The shrinkage was so great that series of cracks formed in regular pattern, with each crack perpendicular to the cooling surface. The stresses producing the fissures were equal in all directions and would have made circular cracks and cylindrical columns; but cylinders have non-cylindrical spaces between them, and the pattern in which the columns are most nearly cylindrical and yet completely occupy all space is hexagonal. So contraction broke the lava into hexagonal columns perpendicular to the cooling surface. The columns are parallel where the lava floor is regular but are curved or radial where the floor is rolling.

Pl. 8. _Trap ridges, near and far._

The columns on Titan's Pier lie across the river from the Northampton-Holyoke road in the narrow gap at Mount Tom station. The basalt flow is inclined 15° southeastward, and the columns stand perpendicular to the surface--hence they are inclined with respect to the water level. Doubtless the devil docked his boat on the gently inclined rock surface of the cove on the downstream side of the pier.

Titan's Piazza is situated east of the road to the Mount Holyoke House. It is an extremely narrow ledge backed by a stockade of columns. The front of the piazza is literally strewn with wreckage from the house, for a slope over 100 feet high is covered with angular pieces of basalt which have fallen from the back wall. The lower ends of the columns break off into shallow hexagonal saucers with the concave sides up. Many have slid down the slope, to the delight of the birds that bathe in them. Higher up the cliff, the saucers become deeper, and towards the top the columns scale on into bullet shaped masses.

_Westfield Marble Quarry_

Anyone who drives westward on the Jacob's Ladder route from Springfield passes first through the open, rolling country of the Connecticut Lowland. Hills are in sight, but they seem remote until he leaves Westfield, and there the upland rises before him like a 900-foot wall. The road uses the gateway cut in the wall by the Westfield River, and the drive westward towards the headwaters of the river is one of the best known scenic attractions in western Massachusetts. But a greater treat awaits the person who will venture southward on the road along the Little Westfield River. It follows the canyon brink about 500 feet above the stream. Near the hilltop, a side road turns north to the Westfield Marble quarry, which provides a vantage point overlooking fifty miles of country to the north, east and south.

The Westfield River meanders eastward across the flat lowland. Its banks are terraced, each level cut in the lake beds or in the delta which the river built in glacial Lake Springfield. The scalloped margins of the terraces are the extremities of meander loops which developed when the river was not entrenched as deeply in the unconsolidated deposits as it is today.

The flatness of the twenty-mile strip of lowland is impressive, for it ends only at the Wilbraham Mountains, eight miles east of Springfield. Beneath the lowland lie soft and gently dipping sandstones and sandy shales, capped by a thin veneer of lake clays and river sands. The shales are the youngest Triassic beds remaining in the region, and they outcrop between Thompsonville and Windsor Locks, Connecticut. Younger shales above them succumbed to Tertiary erosion.

The Wilbraham Mountains are granite and gneiss which formed the roots of the ancient Triassic ranges. Their present accordant summits are a tribute to the leveling activities which running water performed on a quiescent land, whereas the deep V-shaped valleys incised in the level summits record uplift and quickened erosion in Tertiary and glacial time. Indeed, the lowland itself owes its existence to the power of rejuvenated streams working on non-resisting rocks.

The Holyoke and Mount Tom ranges are visible far to the northeast, and a chain of low hills connects Tom with the ridges between Hartford and Avon, Connecticut. These linear hills surmount the lowland because they are made of basaltic lava, which is better able to resist the rain and the weather than the sandstones and shales above and below. Scattered flat-topped hills between Southwick and Granby are sheets of basalt-like rock called diabase, which was inserted between a sandstone roof and floor. Nowhere can one better appreciate the highly individualized imprint which each geological element has made upon the central New England landscape.

_The Old Lead Mines_

The colonial period in our nation's history was characterized by an ignorance of its mineral wealth and a dependence upon Europe for most raw materials, especially essential metals. During the War for Independence, European supplies were cut off, and Yankee ingenuity had to make the most of local deposits of metallic minerals. It was not long before mines were in operation on several lead veins in the Connecticut Valley, yielding a supply of lead for the duration of the war. But the mines were small, and most of them were soon abandoned, remaining only as historical sites, or as collecting localities for the mineralogist. Five of these old deposits are still accessible: four lie west of the valley at Loudville, West Farms, Hatfield, and Williamsburg; an important one is situated east of the valley at Leverett. All are very similar in geology and mineralogy, yet each possesses its own individuality.

The Loudville vein was worked intermittently as late as 1861. It follows a fault fracture between walls of gneiss, but at the southwest end of the vein some of the minerals are disseminated through the Triassic sandstone and conglomerate. This feature indicates that the sediments were unconsolidated at the time of mineralization. The fault zone resembles many analogous fissures which give forth hot mineral-bearing waters in the Basin and Range region of Nevada, for the charged waters have impregnated the sands which cover the fissures.