Ground Water in the Norwalk, Suffield, and Glastonbury Areas, Connecticut

Feet. 72 200 75 Feet. 14 Feet. Inches. Gallons. 3 14 ....do 25 Street . do.... 28 ....do 38 do . . 61 Egbert Lilly . ..do 62 Henry Finch do 63 r. M. Comstock do ... C3A .do do 64 do 51 15 20 6 5 EAST GRANBY. AREA, POPULATION, AND INDUSTRIES. East Granby is a farming town in the north-central part of Hart- ford County and lies about 15 miles north of the city of Hartford. The town has an area of about 18 square miles, of which nearly 8 square miles, or 43 per cent, is woodland. The woods are well dis- tributed but are for the most part restricted to the hills. The territor}^ of East Granby was taken from Granby and Wind- sor Locks in 1858 and incorporated as a separate town. The popu- lation in 1910 was 797, an increase of 113, or 17 per cent, over the population in 1900. The following table shows the population at each census from 1860 to 1910, together with the per cent of change in the decade : Population of East Granby, 1860-1910^ Year. Popu- lation. Per cent change. Year. Popu- lation. . Per cent change. 1860 833 853 754 1890 661 684 797 -12 1870 + 2 1900 + 3 1880 1910 +17 a Connecticut Register and Manual, 1919, p. 638. There has been no uniform trend of change of population, but it has fluctuated in both directions. During the last decade there has been a considerable development of the culture of leaf tobacco for cigar wrappers and binders, and this probably accounts for the notable increase in population. Because of its inferior transportation facilities the town will probabl}^ remain a farming district, and will grow only moderately in the future. The present density of popula- tion is 45 inhabitants to the square mile. : The principal settlement is East Granby, in the eastern part of the town, where there are stores and a post office. There is a smaller EAST GRANBY. 125 \ ilI;i<:;o at (!lraiil)y Station and i)ai1 of 'rai'ifl'ville extends into East (iiauby. Spoonville is a small settlement on Fa)'minp:ton River in the southeast oorner of the toAvn. There are about ;V2 miles of roads in the town. Avhieh ai-e for the most part excellent, thoup:li tli(> roads in the easternmost part are very sandy. The road fi-om Tariff\ill(^ to (rranbj^ Station and the road from Tariffville throujili P^ast Granby to West Suflield are of excellent macadam. The Central New Eng- land Railway runs past the south boundary of East Granby and has a station at Tai-ifFville. A branch runs north from Taiiffville to Springfield and has a station at East (xranby. The Xorthami)ton division (Canal Road) of the New York. New Haven t^ Hartford Railroad follows the west boundary and has ;i station at Granby Station and a flag station at Floydville, a mile south. SURFACE I-KATIRES AND OF,()L(X;iC STRUCTURE. Ea>t Granbv comprises a nearly level sand plain, IGO to 200 feet above sea level, above which rise a large till-covered hill and sev- eral smaller ones. The stream valle3's are cut into this plain. The lowest point in the town is where Farmington River passes the southeast corner, about 100 feet above sea level, and the highest point is the ci'est of Peak Mountain, 665 feet above sea level. The total relief is thus about 565 feet. The sand plain is separated into two parts by the large till-cov- ered trap ridge. It was formed by the deposition of vast amounts of debris washed out from the glacier as it receded from this region and so constitutes an outwash plain. The boundary of the stratified drift lies in general 200 to 240 feet above sea level. Above this height tlie mantle I'ock is till, the direct product of glaciation. The stratified drift forms a very loose, sandy soil, and its upper poi'tion becomes very dry in times of drought, although there may be an abundance of water at some depth. The ecologic conditions are pe- culiar, and the soil has a characteristic flora, in which scrub oak, pines, sweet fern, and a yellowish grass, locally known as " poverty grass," are prominent. This soil, however, is well adapted to the needs of tobacco. Its looseness makes the maintenance of good roads extremely difficult. Plate IX, B (p. 72), which is a view of the sand plain half a mile northwest of Tariffville, shows the very sandy road and the characteristic flora. In the middle distance is the corner of a " tent '' used for raising shade-grown tobacco. The ridge that separates the two sand plains owes its topographic prominence to the sheets of trap rock that underlie it. Most of East Granby is underlain by red sandstones and shales dej)osited during the Triassic period as sands and clays and subsequently indurated. The process of deposition was interrupted on three occasions by the 126 GROUND WATER IE" ISTORWALK AND OTHER AREAS, CONN. quiet volcanic extrusion of basic lava which spread out in broad sheets and eventuall}^ solidified as trap rock. South of Tariff \'ille there are three trap sheets, of which the middle is the thickest (400 to 500 feet) and is therefore known as the " Main" sheet. Below it and separated from it by 300 to 1,000 feet of sandstone and shale is the " Anterior " trap sheet, which has a maximum thickness of 250 ; feet, and is so named because it outcrops on the front or face side of the cliff formed by the " Main " sheet. Above the " Main " sheet and separated from it by 1,000 to 1,200 feet of sandstone and shale is the " Posterior '' trap sheet, 100 to 150 feet thick. The " Anterior " sheet thins out north of Tariffville and outcrops only in a few places. At some time subsequent to their consolidation the sedimentary rocks and the associated traj) roelis were broken into great blocks and tilted 15° or 20° E. Davis ^ has recognized and mapped one prin- cipal fault that bears about northeast and several minor faults that bear north or a little west of north. The ridge of Peak Mountain Vertical scale twice the horizontal EXPLANATION Sandstone Trap FiGUKE 18. — Greoio,sie section acroas East Graubv and Snflield (S!>ction !>-!)' on PI. V). Stratified drift and till stands up because of the thick, resistant " Main " tra|) sheet that forms a bold westAv a rd- facing cliff'. The ridge is broken by a gap about 200 feet deep where it is crossed by the Tariffville-Springfield Railroad, This gap is due to the major fault, which offsets a little the portions of the trap sheet to the northwest and southeast. The! gorge of Farmington River at Tariffville was formed by deep erosion of a fault zone along which there was similar offsetting. This fault zone bears a little west of north. The block on the east was raised and moved soutliAvard so that the offset of the north part of the ridge relative to the south part was to the east, Plate X, A, shows the offset to the east or left of the nearer or north part of the ridge as seen from a point a mile north of Tariffville. The minor faults produce offsets on a smaller scale but of similar char- acter. A section across East Granby and Suffieicl along the line D-D' on the map (PI. V) is shown in figure 18, and the relation of the ridg'es and the plain to the underlying formation is there illustrated. ^ Davis, W. M., The Ti'iassic formation cf Connecticut : U. S. Geol. Survey Bigliteentli Ann. Kept, pt. 2, pi. 19, 1897. U. S. GEOLOGICAL SUKVKY WA'l'Kll-SUri'LV rAl'KIt t70 I'LATK X <imm ^1^ A. OFFSET TRAP RIDGES NEAR TARIFFVILLE, CONN. B. FLOWING WELL DRILLED IN SANDSTONE, EAST GRANBY. CONN. EAST GRANBY. 127 The part of East Granby west of Peak Mountain and its southerly prohtnoation is drained by a branch ol' Sahnon Hrook. which joins Faruiini^lon River near Tarift'ville. In the southeiii part cast of the ridge is a small area drained by short streams which empty directly into the Farmington. Most of the area east ol" tlie ridge, however, is drained by rather long northward-flowing streams that are tributary to Stony Brook (in Suffield), which empties into Connecticut TJiver. AVATER-BKARINO TORMATIOXS. Red saruhtone. — ISIost of P^ast Granby is underlain by rod sand- stone and shale of Triassic age. The beds have been tilted 15° or 20° E., and the rocks have been broken by the jarring, so that they are now traversed by many joints and large fractures. These openings form systems which tend to be either parallel or at right angles to the bedding. Water that has found its way into them from the overlying unconsolidated till or stratified drift may be recovered by means of drilled wells. The average depth of the 11 wells of this type that were visited in Suffield is 211 feet, and their aAerage yield is 20 gallons a minute. In much of the area a thick deposit of stratified drift mantles the sandstone. In places the stratified drift is as much as 100 feet thick, as shown by Mr. George Batytes's well (No. 5, PI. lY). which went through 100 feet of sand, silt, and gravel before reaching the bedrock. In such places abundant supplies would probably be obtained in the stratified drift without drilling into the bedrock. The drilled well of Mr. I. H. Griffin (Xo.^33. PL IV) is one of the few flowing wells in the State. It is probable that this well has cut one of a series of interconnecting fissures that are sealed in some- way. The well is on the east slope of a low ridge, and considerable ]\ead is developed in the higher part of the ridge. The sealing lielow the well or to the east may be either due to the pinching out and narrow'ing of the fissures or to a blanket of impervious over- lying till. The till on the hilltop must be pervious, else water could not enter the fissures. K view of the mouth of this well, showing its normal flow of 1| gallons a minute, is given in Plate X, B.