Ware Town

General Besceiption

The eastern band of schists leaves the county at the south line of Orange, and, traversing Worcester County for a long distance, reenters the area of the map in Ware and crosses Palmer and Monson. The fourfold division of the schists, which has been persistent over so large an area, and which seems to be somewhat less distinct at the beginning of this band in Orange, here fails entirely. It is reduced to a twofold division of amphibolites below, resting directly upon the Monson gneiss, and a great volume of fibrolitic mica-schists, the lower portion of which may represent the whetstone-schist, but in which no persistent lithological distinctions can be established.

On the map I have given to this band a color resembling that given to the Conway mica-schist, since in Orange and Warwick the gradual passage of schists whicb are lithologically and stratigraphically the representative of this terrane into these fibrolite-schists can be clearly followed, and the lessening of the number of distinct bands above the amphibolite seems to be efiected mainly by the suppression of the whetstone-schist or its merging with the hornblende-schist, with which it seems more intimately connected than with the upper bed, rather than by its becoming lithologically like this upper bed - that is, like the Conway mica-schist.

Across Ware the amphibolite can be followed with apparent continuity (it is, of course, miich covered by loose deposits), bordering the fibroliteschists on either side and separating it from the Monson gneiss below It presents no peculiarities of interest.

The fibrolite-schists are deep-brown biotite-schists, in wliicli the redbrown shade of the biotite is very characteristic. A fine, silky fibrohte is very abundant. Deep-red garnets are common, and it is largely due to their ready decomposition that the schists have always at surface a very riisty appearance. Nodular masses of a perfectly fresh and limpid moonstone, often across, and generally consisting each of a single untwinned crystal, appear at times abundantly in the schists, whose layers wrap round the nodules so that they seem like pebbles. They are often surrounded by a border of sugary, white, granular feldspar, plainly formed by the crushing of the large central mass and the slight displacement of the fragments produced. This displacement becomes at times considerable in the direction of the bedding; and the granular material is drawn out in tails forming complete "augen," which, with their centers of orthoclase as limpid as calcite, stand out in marked contrast with the deep red-brown of the schist. They inclose occasionally garnet and graphite, but I do not recall an inclusion of fibrolite. Grraphite in minute scales is everywhere present in the rock and is at times quite abundant.

Petrogeaphical Description

Mica-schist from Ware. In the bluff near the contact of mica-schist on hornblende-schist, 175 rods southwest of B. Bond's house, is seen a black, fine-grained schist with wavy, shining lamination surface, which may almost be called an argillite, with rarely deep-red garnets and large porphyi-itic spots of white feldspar.

In section the dark color is seen to be due partly to trains of coaly matter, but more to the dark color of the biotite scales, which are dark olive-green in thin plates.

The garnets are apolar and without inclusions. The feldspar is orthoclase, with no trace of microcline. The rock is very interesting from the pseudofluidal structure developed by the gradual growth of the orthoclase in the mass. The centers are large, rounded or quadrangular masses of feldspar, showing at times very faint undulose extinction. At either end are grouped a congeries of intergrown grains vaiiously arranged optically, and tapering away to form with the central pieces "augen," around which trains the mica-scales curve. Outside these other bands of feldspar grains appear, and converge in either direction to meet and inclose the central band of mica scales. Outside this another band of mica scales widens out to iiR'luilc the wlidle, and this is sometimes repeated several times on one or both sides of the center, showing a gradual growth of the feldspar within the mass of the mica-schist. There was first tlie formation of the large central mass and its welding with a layer of the mica scales at its surface (scattered scales of the same mica occur within the large feldspars), and later the addition of other granular layers of feldspar outside the first, each retaining in contact with its outer surface a film of the mica scales. Each feldspar layer has possibly some relation to a stage in the folding process of the rock, by which strains were set up within it and localized at the surface of the feldspar grains, so that growth of new feldspar at that place was made possible.

The Hardwick Gneiss

In a communication to the Geological Society of America a\ New York in 1889^ I described briefly the great bands of granite which cross the State as batholites of igneous rock, melted up along great synclines of the compressed schists, and stated that the Cambrian biotite-gneisses, which are sometimes finely granitoid from recrystallization, could scarcely be distinguished from these granites made schistose by crushing, and I held the Ban-e and Orange bands in reserve, as their relations to the gneisses and to the granites were so evenly balanced that I could not decide in which category to place them. A more extended study of the band across Massachusetts and New Hampshire has convinced me that it must be put with the intrusive bands, as it shares so m.any of the characteristics of the latter. It is intruded as a broad band in the fibrolite-schists, while if it were the Monson gneiss in normal relation to these schists in the core of an anticline it would be separated from- them on either side by amphibolite and whetstone-schist, as is the case in the anticlines next east and west. Now, the northern end of the next eastern band - the Orange band - is the counterpart of the northern end of this mass. The shape is the same; the rocks are in places scarcely distinguishable; but the newer rocks seem to mantle round the Orange area as around a core of gneiss, and the band can be traced continuously south into union with the Palmer-Monson area, where the interbedded quartzites and conglomerates prove the mass to be a Cam-

' Porphyritic and gneissoid granites in Massachusetts: Bull. Geol. Soc. Am., Vol. I, 1890, p. 5.59. The name Barre granite used here has been changed above to Hardwiok granite to prevent confusion with the Tvell-kuown granite of Barre. Vermont.

brian gneiss. I am thus constrained to leave the Orange band with the gneisses and to assign the Hardwick band to the granites, in spite of their resemblances. The latter band widens as it goes north, and crosses the State line with the whole width of the country between Royalston and Winchendon, and ends with the characteristic blunt point north of Fitzwilliam ; and the line of the syncline continued passes under Monadnock, and the granites possibly continue along this line, beneath the mountain, and have caused the large development of andalusite in its schists, as they have on the border of the Princeton band and in the center of the Worcester slates. Only its southern, narrowed end enters the territory under review, in Ware, and runs down the eastern portion of the Palmer quadrangle. Across the whole State the narrower western portion of this baud is a very dark granitite - generally dark from excess of black biotite, more rarely by the presence of jet-black hornblende. The eastern portion is an excellent biotite-muscovite-granite, like that of Fitzwilliam. The darker portion is well exposed in the railroad cut at Gilbertville, and is described below. Where the Coys Hill granitite crosses it it carries large "augen" of adularia, like the adjoining schists. It is thus older than the post-Carboniferous granites.

The rock may be studied best along the road running east from South Monson and near the east line of the town. At L. Bradway's it resembles a good typical Monson gneiss, as also at B. Brook's. At T. Sutleff's a black granular hornblende-granite, a dark biotite-granite with amber feldspar, and a granulite full of shining- white fibrolite occur on this terrane. Such fibrolite always appears to have been dissolved in granite, being derived from the adjacent fibrolite-schists.

Petrographical Description

At the first cutting on the Central Railroad northeast of Gilbertville station, 1 7 feet east of a pegmatite dike, occurs a rather fine-grained granite, nearly black from the abundance of biotite and magnetite, and of slightly subporphyritic aspect from the presence of disseminated scales of biotite, or groups of scales 3-4°"" across.

Under the microscope it is a wholly fresh, highly crystalline granitoid rock. On a background of closely interlaced grains of oi'thoclase and plagioclase an abundance of biotite, magnetite, and epidote appears. Quartz is wholly or almost wholly wanting, and there is no trace of microcline. The olclur constituents are apatite, magnetite, zircon, rutile; the newer, biotite, orthoclase, albite, epidote, ])yrite. Apatite is very abundant, as is also magnetite; pyrite is rare. The abundant biotite shows the richest absorption colors.

A large crystal of albite contains many small, sharp plates of biotite parallel to 0 P (001) and oo P o6 (010), and the section is so exactly parallel to X P 00 (100) that these plates are both presented edgewise to the eye. It extinguishes the light at 22° and 23° with the twinning plane, while the mica plates make witli each other an angle of 94°. It is also crowded with minute black rutile (!) microlites, which are broken up to an unusual extent into short rods, or often into long, rigid rows of black dots parallel to 0 P (001) and oo P ob (010), and in other directions as well. The epidote usually associated with the magnetite shows striking absoi'ption - a = colorless, h = pale mountain green, c = salmon color. The zircon is in small, rounded, limpid grains, with rounded liquid inclosures, or many large elongate, stout prisms with several constrictions and centrally densely dusted with black grains. This agrees closely with the type of zircon occurring in the gneisses as determined by K. de Kroustchoff.^

Palmer

Across this town the western band of amphibolite is broad and well marked; it commences where the town line runs north nearly to the Ware River, and continues south to Fentonville, being well exposed west of E. Shorley's in the middle of its length. The eastern band is wanting.

The mica-schist extends across this town with less width than it has thi'ough Ware. The great east-west fault through the south of Ware, on the south of which the rocks are thrust far to the westward against the granite, seems to account for this. The schists in the northern half of the town are dark, rusty, fine-grained biotite-schists, in which fibrolite is exceptionally rare, but it sets in again abundantly in the southern part of the town.

Mon Xxix 16

After passing over the Monson gneiss and the amphibolite one comes upon a hand of gray, fine-grained, thin-fissile gneiss containing garnets, which represents the whetstone-schist, but is so thin that it is not separately represented upon the map. It contains a small amount of fibrolite in the finest needles.

Just above it is a dark, fine-grained mica-schist, full of small garnets and spangled with transverse biotite that exactly resembles the Conway mica-schist, except that it contains fibrolite.

On the next road south, in the roadside by S. Blodgett's, the rock is a ^'ery striking one. It was originally an arenaceous band in the mica-schist, like the whetstone layers in the Conway mica-schist on the west of the river. It has now assumed the chocolate-brown color of the rest of the rock, and is full of fibrolite needles that wind with an excellent imitation of a fluidal structure around porphyritic masses of feldspar or garnet, which reach a diameter of and very closely imitate pebbles. They are well rounded, but consist in each case of a single crystal.

The feldspar is a perfectly fresh and slightly opalescent moonstone, regularly penetrated by blades of plagioclase so exceedingly fine that, except with thin plates and very high powers, it seems to be an orthoclase of ideal purity. These rounded masses are bounded by a sugary, granular border of white feldspar, clearly produced by the crushing of the central mass, and I have nowhere seen the cataclase structure more beautifully developed.

The average rock of this band aci-oss Monson is a rusty, chocolatebrown biotite-schist, everywhere abundantly fibrolitic and graphitic, and very generally carrying garnets. Occasionally it is changed into a gneiss, as described above, by the development of the porphyritic feldspars, but this seems so plainly a modification of the mica-schist during folding, by the warping open of cavities which became filled with feldspar, that I have not separated it upon the map.

On the east of the mica-schist only traces of amphibolite could be found along the line of separation of the schist and the band of gneiss still farther east, and this could not be given on the map without great exaggeration.

Silurian Schists On East Side Of Valley The Pyroxenic Amphibolites

An inspection of the map will show that the crystalline rocks are thrown off on all sides from the flanks of the great Belchertown "batholite," and that great sheets of the same rest on the tonalite far out in the center of the mass. These are of the varieties most characteristic of intense contact metaniorphism - coarse fibrolite- and pyroxene-schists, epidosites, and highly silicified gneisses and quartzites.

The zone of crushing following the foothills through Leverett, Pelham, and Belchertown passes directly thi'ough this contact border and materially increases the difficulty of identification and correlation of the beds with their equivalents elsewhere.

It is not possible to distinguish between the beds below and those above the amphibolite, since the quartzite becomes heavily loaded with biotite, forming a fissile gneiss, which I have found all around the mass and have in my notes called the Baggs Hill gneiss, from its abundant development in this hill in Granby near the Belchertown line. As soon as it approaches the granite mass the amphibolite becomes pyroxenic, as at Kelleys Crossing and on south down the west side of the mass, while the Conway schists become coarse fibrolite-gneiss and epidosite.

The band of amphibolite which was traced through Leverett to Adams's mills reappears between the two Belchertown ponds and wraps around the south end of the Pelham gneiss, uniting the Leverett-Amherst area and the Pelham-Shutesbury syncline, and extending across Belchertown Center with great width because of the disturbing influence of the tonalite. It is much shattered, and swarms with small aplitic dikes from the tonalite.

A sahlite-amphibolite appears at the point where the road from Amherst to Belchertown crosses the railroad - in the new cutting of the Massachusetts Central Railroad - and a short distance farther south in the cutting of the New London and Northern Railroad at the next crossing (Kelleys Crossing).

Here the rock is a coarse amphibolite of dark-green color, made up almost wholly of broad, interlacing plates of hornblende. It is much cut by dikes of a flesh-colored granite (aplite) containing little mica, which send small veins through it in all directions, recementing the brecciated mass.

Bordering these on all sides, in a width from one-half inch to 2 inches, the hornblende is changed into a much lighter green sahHte, plainly a contact product. At the south outcrop a band of the pyroxene rock much wider occurs, which is not in visible relation to the granite.

The schist is in places rendered gneissoid by the intrusion of sheets and small irregular aggregations of flesh-colored granular feldspar, which can at times be distinctly traced back into connection with the granite.

Followed south along the road the rock becomes again a chloritic hornblende-gneiss, and just beyond and east of its southern outcrop appears a band of quartzite and mica-schist, which is exposed in the cuts of the two raih-oads and seems to overlie the hornblendic rock, as indicated in the section and described below. (See fig. 14.)

In the roadside 165 feet below J. Squire's and in the cuttings of both the railroads above (east of) his house occurs a flat, thin-fissile, feldspathic mica-schist of dark greenish-gray color and so full of small cubes of pyrite that it is deeply decomposed. Dikes of coarse pegmatite from 1 to 25 feet wide cut through it, and they also contain pyrite and are kaolinized to great depth. The mica-schist is 10 feet thick.

Below this is a thin-bedded, light-gray quartzite, slightly biotitic on cleavage faces. It is much fissured, and filled with combs of quartz, films of hematite, and calcite, and slickensided. Below this, on the west side of the road, is a massive, crumbling amphibolite, which seems to underlie the quartzite. The section is here sufficiently undisturbed to show the amphibolite in normal relation to the upper beds.

Along the road farther south, in the field east of T. S. Haskel's, is an outcrop of a coarse sahlite-amphibolite, like that at Kelleys Crossing, which joins Monson gneiss on the east and is cut off by a great granite vein upon the south. It is still coarser than that farther north, and the pyroxene crystals are larger. It furnished the material for the microscopical description of the rock below. It is a massive, friable, granular mass of greeu p\TOxene grains, with here and there a great bhxck hornblende crystal appearing porphyritically in the mass, its shining surfaces luster-mottled bv many grains of" the pale-green pyroxene, which are here better crystallized and smaller than in the main mass. The pyroxene is colorless, without ])ina<'oidal cleavage or inclusions of any kind.

This is the rock that was called augitic syenite by President Hitchcock, and slides were cut from the specimen in the survey collection (XVIII, 92). The rock contains large leek-green crystals of pyroxene, large black hornblendes, and a scanty granular groundmass of plagioclase.

In slides the dark-green hornblende, which is at times brown centrally, is luster-mottled on its broad cleavage surfaces with pyroxene, which is faintly reddish, of high refraction and coarse cleavage. The large pyroxenes are intergrown with irregular portions of hornblende with the axes a and h of the two minerals parallel. In sections normal to h the cleavage lines coincide and a revolution of 17° to 19° brings the hornblende to extinction, and of 43° in the same direction, the pyroxene. The two minerals are so interwoven that they give almost an aggregate polarization. Small, brown octahedra appear in the hornblende. In general the amphibolite is not made pyroxenic, but is only crushed and filled with quartz veins. It is the usual flat-fissile, dark, fine-fibrous rock.

Still farther south, on the west slope of Baggs Hill, in Granby, appear dark greenish-gray, membranous, feldspathic mica-schists, associated with a quartzite which is at times blackish, at times greenish, and abounds in quartz crystals and pyrite.

The Fibrolite-Schist Inclusions

The most instructive occurrence to prove the eruptive character of the tonaHte and to ilhxstrate its contact phenomena is found in the broad sheet of coarse fibroUte-schist which runs two miles southwest from "Slab Citv," in the east of Belchertown, to end at the house of V. H. Pease. In the middle of the road that runs along its southern border at the western Clough house - this and the Pease house being the only ones on this road - at a watering trough, a brook crosses the road, coming down over the rocks, and 30 feet above the road one sees the contact of the tonalite and the schists above it, and at the trough the quartzite appears as a gramilar quartzeijidote rock. The bright yellow-green epidote is in rounded crystals, each surrounded by a white spot, from which the iron has gone to supply the epidote crystal.

At the northeast end of the inclusion, at G. Robinson's, a dark biotite schistose gneiss, like that found at Baggs Hill, dips normally under the fibrolite-schist. The biotite is black, with a shade of green, and makes continuous films through the granular quartz mass. Below this gneiss are beds of a thin-fissile, slightly micaceous quartzite.

This fixes the position of the fibrolite-schist as the equivalent of the upper mica-schist, as does the fact that it lies in continuation of the micaschists in Enfield, and the latter are the only beds sufficiently argillaceous to have furnished material for so much aluminous silicate. These same mica-schists grade eastward into fibrolite-schist and continue across Worcester County, but they are rarely so coarse as here,

Petkographical Description

Fibrolite-cJilorite-scJiist, from bowlder in cutting on Massachusetts Central Railroad, South Belchertown, but coming doubtless from the contact zone of the granite; a stretched gneiss-like rock of gray color, with shade of green and showing much fibrolite.

Under the microscope radiated fibrous tufts of a green, chloritic mineral inclose much graphite in notched plates, and this chlorite is associated with an abundance of large garnet grains free from the same inclusions, and these together frame large grains of quartz full of rutile needles. The quartz polarizes as a mass of grains and is plainly secondary. The fibrolite is abundantly woven through the whole.

Contact Around Belciiertown Tonalite

I'lbrofite-biotitc-schist, from south end of the main belt of schist in the granite. This is a coarse schist, showing an abundance of muscovite and biotite, rusty," and containing large spots of garnet and coarse fibrolite blades, often 3-5""" wide.

'J'he microscope shows many black scales, part of which are blood-red specular iron, and part seem to be graphite, as they are grown together in long lines and have rounded outlines. There are many rutile needles in the quartz.

Garnet-staurolite rock, from large bowlder in the first cutting of the Massachusetts Central Railroad south of Belchertown, and coming doubtless from the band of fibrolite rock to the north. This rock represents the extreme of metamorphism reached by the rocks bordering the granite. It is a highly crystalline rock of medium grain. Large patches of garnet and quartz and much biotite are visible to the eye, and the lens detects much staurolite, graphite, and a few shining surfaces of fibrolite.

Under the microscope nearly half the surface is occupied by staurolite; the garnet patches are seen to be made up of congeries of small grains, and these two separate quite widely the quartz patches, which are crowded with fibrolite and rutile microlites and are thus plainly secondary quartz. All these minerals include plates of graphite scales - single or grown together in long series.

Epidote rock, from Belchertown. This is an interesting product of the contact metamorphism of the tonalite upon the schist. It occurs at the watering trough near the house of J. Clough, in the southeast part of Belchertown. The rock has a mottled look; a white groundmass winds among rounded spots of a dark yellowish-green color, made up of biotite and epidote. The rock grades into biotite-gneiss.

The epidote is the most abundant constituent, and with a strong lens one can make out the fresh, shining-, model-like crystals, regularly disseminated, and semiopaque centrally. With the microscope they are seen to be filled with grains of quartz, of elongate, irregular shapes, and very large in proportion to their host, which crowd the central portion and radiate outward. It contains, also, chlorite scales. Biotite, regularly disseminated and strongly dichroic, molds itself to the epidote, as does the rare quartz. Apatite occurs in regular crystals, forming pleochroic rings in the biotite.

All the constituents are perfectly fresh and almost entirely free from fluid inclusions and microlites, and the absence of these, as also of zircon, rutile, garnets, and iron ore, is remarkable.

Hand specimens are on one side biotite-gneiss, on the other epidosite, and the two seem normally interlaminated ; but the latter must be of later and very different origin, and may be in effect a vein stone, in which, perhaps, the chlorite scales are remnants of the earlier rock, which has been almost wholly resorbed to make place for the new minerals.

South of the deep transverse valley of the Quabaug and its continuation in the Chicopee River, the simplicity of the geology is as marked as is the complexity of the region north of the same valley. Three great synclines of the schists run south across the towns named above, forming as many high ridges. The Wilbraham sjmcline looks down on the sands of the Connecticut Valley on the west and upon the deep gneiss-bottomed valley of East Wilbraham on the east, and across this valley rises the West Mountain of Monson, made up of a second syncline of the same rocks and looking down on the deeper and narrower Monson Valley, which is underlain by the same gneiss. Across this valley on the east the third syncline rises to form East Mountain, which is bordered on the east by a less strongly marked and yet distinct valley, underlain by a third repetition of the Monson gneiss and, followed farther east, by the Brimfield gneissoid micaschists, forming a foiirth syncline. (See sections, PI. XXXII, and map, PI. XXXIV.)

The Wilbraham syncline is concealed in its western half beneath the Triassic sandstones, which rest against the western foot of the ridge, and the slope of the ridge on the west is so steep that it is probable that the fault, so well marked farther north, is continued at its base, and that the rocks have sunk to form the broad Connecticut Valley. It is a closed fold, slightly overturned to the west, and its rocks closely resemble the corresponding beds on the west of the Connecticut Valley in Granville.

The gneissoid quartzite or muscovitic gneiss, the equivalent of the Rowe schist, which usually intervenes between the Monson gneiss and the hornblendic beds, seems to be wanting here, and the hornblendic beds rest directly on the white biotite-gneiss. The upper beds of this gneiss are very fine-grained and magnetitic and probably represent the Rowe schist, but

The Wilbraham And Monson Synglines

The hornblende-schist (Chester amphibolite) is a jet-black rock, satiny on the surface from the eifect of the great number of fine needles of hornblende which make up nearly its whole mass. The whetstone-schist (the equivalent of the Sa\'oy schist) is a gray, granular, friable quartzite, varying from thin-fissile to massive, often a shining muscovite-quartzite, or abounding in distant flakes of chlorite. It is covered on the western flank of the syncline until the range crosses into Connecticut, when it appears on the west flank of Perkins Mountain.

The Conway mica-schist is a coarse, light-gray muscovite-schist, generally barren, but caiTying at times a few garnets. Along its western base it is much crumpled and silicified, as if from the influence of the fault.

On passing into Connecticut the regularity of the syncline is interrupted. The amphibolite band which forms the ridge of Pine Mountain, Rattlesnake Hill, and Perkins Mountain, in Somers, is suddenly cut off" in the south shoulder of Perkins Mountain by the gneiss. The latter rock, which up to this point has dipped a little north of west, here swings around sharply, dipping steeply north and northeast, so as to cut off the whole series up to the mica-schist, and, reversing its direction, it runs south again, dipping normally beneath the Conway schist, of course with a fault boiuidary.

The west Monson syncline is a perfectly symmetrical closed fold of the scliistose series in the gneiss, and its character will be understood by comparing the detailed section below with the cross-sections on PI. XXXII. The section given below commences with the older rock - the Monson gneiss - on the east, at a point 1,830 feet east of the sharp turn in the road at the house of A. Bliss, jr., a mile northwest of Peaked Mountain, and runs west : b. Eowe schist. Gneissoid quartzite, with very little feldspar, muscovite, and a green mica or chlorite, with beds of gray biotite-quartzite, chlorite-schist, and hornblende-schist appearing a little farther north, opposite the house of J. Burley ; 361 feet.

e. Savoy schist. Cbloritic mica-schist, with subordinate beds of muscovitegneiss, changing above into arenaceous mica-schist (whetstone-schist) and still higher

/. Conway schist. A coarse, lead-gray, barren mica-schist occupies about half the thickness of this bed and is succeeded above by a corrugated mica-schist of fine grain, very dark, from the large amount of graphite in it, and abounding in small garnets (oo P) and dark red-brown biotite, set transversely to the bedding; 1,188 feet.

The similarity of this series to the corresponding one across the Connecticut Valley is striking. Each subdivision between the Becket gneiss and the Leyden argillite is represented, though vpith diminished thickness. The Savoy schist (e) is well exposed in the first cutting west of the Palmer station on the Boston and Albany Railroad. Here there is trace, apparently, of a corrugation of the quartzite, upon which the vertical foliation may be superinduced as a secondary structure. This would throw doubt upon the thickness given above. Following the Somers turnpike a mile and a half west from the south end of State-line Pond, in Connecticut, at the south end of the long ridge of Peaked Mountain one comes upon the finest quartzconglomerate in the Rowe schist. It is in a great ridge on the north side of the road, at a ruined house northwest of the schoolhouse.

The mica-schist (/), the central portion of which agrees strikingly with the Conway schists clear across the town, is best studied where the road from iPalmer to Hampden crosses it, a mile northwest of Flynt's quarry. The uppermost beds are so fine-grained and plumbaginous that they recall the Leyden argillite, and this is exactly the horizon at which it should occur.

If the section be continued westward it repeats itself exactly in inverse order, though here the amphibolite is very generally porphyritic in appearance - a structure which is due usually to the absence of hornblende from small spots regularly disseminated, so that the whole granular groundmass shows; but many bowlders of the rock found in the southwest corner of Monson are of fine, porphyritic diorite-schist with fresh, poorly cleaving feldspars in close-set, rounded grains.

It seems to me probable that a narrow fragment of rocks of this series starts east of Flynt's quarry, near the "rock house," and extends north thrditgh Bunyan Mountain, either faulted down into the center of the anticline or brought there by a subordinate downward fold of the schist which foi-merly mantled over the gneiss. It was of too limited extent to find place upon the map.

Contact Around Belchertown Tonalite

A naiToM' s>-iu'liue comes out from beneath the sands east of Greenwich village and near the east line of Greenwich. Traces of it appear to the north, mostly covered by sand, along- the roadside east of Warner's pond. It makes tlie high hill which extends down the east line of Greeiiwich and Enfield, and is well exposed along- the road running east from Enfield. Here, near W. N. Avery's, the fibrolite-schist is a nearly pure bucholzite, in thick layers, in a fine-grained feldspathic quartzite without brown mica, gi'aphite, or garnet. As it lies immediately above the amphibolite it occupies the position of the whetstone-schist. The center of the series is occupied by the rusty mica-schist, while on the west there is a dull-greenish graphitegarnet-muscovite-schist and a granulite with its gai-nets bordered by green, and both these beds indicate the presence of the basal beds below the amphibolite, but not in thickness sufficient to be put upon the map. In Ware this terrane is well exposed between the town farm and the schoolhouse to the west.

It is shifted to the west by the great fault in the south of Ware, and across Palmer it forms the high Pattaquattic Hill and the range of high ground south across the town. On the south flank of this hill, northwest of J. Can-igan's, the black mica-schists are locally so crowded with the large rounded "augen" of feldspar that the separated folia of the schist, 2-5"" thick, w^ind in and out among the latter and occupy not more than a fourth of the space in a cross-section of the rock.

In Palmer it can best be studied along the road running east from the Center, and its first branch to the northward, especially in the hill east of B. Olney's. Here a distinct band of quartzite appears above the amphibolite. It runs out soon after reaching Monson.

Connecticut With Those On The West

In the north of the State the beds in the first band east of the river agree most closely with the con-esponding beds west of the river, and some of them, as the Conway schists, agree exactly in a multitude of characters. Southward the strata change greatly, but in the latitude of Amherst the corresponding strata east and west of the river still resemble eacli other closely. Farther south the beds revert to the types prevalent in the northern part of the State, but with many minor peculiarities, and still the resemblance is close, bed for bed, between those on the east and those on the west of the river.

On the north of Warwick the Conway schists agree exactly with those in the Northfield syncline next west, and thus with the type west of the river. As the beds are traced south along the strike they gradually become fibrolitic, and the same change takes place slowly across the strike as one goes eastward into higher beds.

Because of the abundance of granite, metamoi-phism is more pronounced in the central part of the State, and here fibrolite occurs in the schists all the way to the Connecticut. Again, where the nonfibrolitic Conway schist passes out over the Belchertown tonalite it becomes most coarsely fibrolitic. Finally, as the beds are followed still farther east across Worcester County the great increase of granite promotes a corresponding increase of fibrolite in the highly aluminous Conway schists, and they are named for convenience the Brimfield schists.

The Bernardston Series Of Upper Devonian Rocks Literature

15. 1873. J. D. Dana. On rocks of the Helderberg era in the valley of the Connecticut; the kinds including staurolite slate, hornblende rocks, gneiss, mica-schists, etc., besides fossiliferous limestone. Am. Jour. Sci., 3d series. Vol. VI, p. 339.

18. 1877. J. D. Dana. Note on the Helderberg formation of Bernardston, Massachusetts, and Vernon, Vermont. Am. Jour. Sci., 3d series, Vol. XIV, p. 379.

History

1819. "Argillite sometimes alternating with mica-slate, siliceous slate," "undoubtedly primitive." Almost perpendicular, inclining a few degrees to tlie west. (1,^ p. 105.) The hornblende-schist of this series is associated with the Triassic "greenstone." (1, p. 109.)

1823. Extends from Leyden, north to Rockingham, Vermont; occurs again at Woodbridge, Connecticut; often tortuous and slightly undulating, especially when passing by imperceptible changes into mica-slate. It embraces numerous beds and "tuberculous masses" of white quartz. It also alternates with mica-slate, and a peculiar coarse limestone forms beds in the argillite. The map separates the argillite from the mica-slate on the west by a continuous band of limestone and extends it eastwardly to include all the mica-schists which have been associated with the Bernardston limestone in later time, while the mica-schists on the eastern side of the river are associated with the mica-slate west of the argillite, (2, p. 36.)

1832. The limestone and magnetite beds which had been worked forty or fifty years before, but had produced poor iron, are described briefly in their economic aspect but without geological data. (4, p. 27.) It was supposed to form a bed in the argillite. Compares it in value with a gold or silver mine.

1833. Fossils discovered in the limestone and figured (6, atlas, pi. 14, p. 47) ; and the limestone, though not seen in contact, supposed to lie unconformably upon the argillite. The quartz rock lying above the limestone, but not seen in contact, is noted. The complex folding-s of tlie arf)-illite iu-e described and fig'ured. (6, pp. 289, 295.) Concludes that the encrinal limestone is newer than the argillaceous slate.

1841. Doubts are expressed as to the encrinal character of the fossils. The relations of the argillite, limestone, and quartzite described as before. (7, pp. 54, 556, 560.)

1851. Because of the discovery of an upper stratum of slate (the upper schist described below) beneath which the limestone passes, it is decided that the whole of the argillite together with all the series to the top of the upper schist of the section on page 258 is Devonian, in accordance with the determination of the crinoids by Prof James Hall, who thought them to be of the age of the Onondaga limestone. (10, p. 298.)

1858. Bernardston and West Northfiekl are divided about equally by a north-south line between argillaceous slate on the west and hornblendeschist on the east, with the number for mica-slate entered on the area of the latter, but not subdivided from the rest. Limestone and iron ore marked. (11-)

1861. While the preceding history has dealt entirely with, the work of President E. Hitchcock, I understand, though it is not distinctly stated in the