| lu |
GLACIAL LAKE UNCASVILLE DEPOSITS (Uncasville, Montville, Norwich) SL-- Ice-marginal deltas and fluviodeltaic deposits with deltaic surfaces at 55-65 ft (17-20 m) along the Thames River and Poquetanuck Cove. Fluvial deposits on grade with the deltas reach 95 ft (29 m) altitude in tributary valleys. Coarse gravel fluvial deposits in lower Oxoboxo Brook valley reach 235 ft (72 m) and have a very steep surface gradient to the 65 ft (20 m) delta at Uncasville. Lake was ponded behind the Ledyard Moraine and deposits of unit Cjt in the Thames valley; the sediment dam has largely been removed by postglacial Thames River entrenchment. |
| mp |
MASHAPAUG POND DEPOSITS (Wales, Westford) IP-- Ice-marginal deltas built into a series of small lakes ponded against the upper Quinebaug-Shetucket River drainage divide at five successively lower spillways across the divide at altitudes of 965 ft (294 m), 905 ft (276 m), 875 ft (267 m), 835 ft (255 m) and 705 ft (215 m). Deposits are particularly rusty because of abundance of sulfidic schist fragments. |
| cr |
CONAT BROOK-ROARING BROOK DEPOSITS (Stafford Springs, South Coventry) IP-- Ice-marginal deltas built into two groups of small lakes on east side of Willimantic River; deposits in Conat Brook valley were controlled by successively lower local spillways at 720 ft (220 m), 665 ft (203 m) and 575 ft (175 m). Deposits in Roaring Brook valley were controlled by spillways across divide between the two valleys at 655 ft (200 m), 635 ft (194 m), 615 ft (188 m) and 535 ft (163 m). |
| cs |
CEDAR SWAMP AREA DEPOSITS (South Coventry)IP-- Successive ice-marginal deltaic deposits in Cedar Swamp valley and in north draining tributaries to Eagleville Brook valley, Conat Brook valley and small tributary valleys on east side of the Willimantic River. Earliest deposits in Cedar Swamp valley contain extensive ice-channel fillings and were controlled by a 555-ft (169-m) spillway; these deposits blocked the valley. Successive deposits north of Cedar Swamp were controlled by a 585-ft (178-m) spillway. |
| fv |
FITCHVILLE DEPOSITS (Fitchville, Norwich) IP-- Ice-marginal deltas in seven north-draining tributaries to the Yantic River; single deltas in each valley were controlled by spillways across each local divide. |
| gl |
GARDNER LAKE LACUSTRINE DEPOSITS (Fitchville, Colchester) IP-- Successive ice-marginal deltaic deposits in north-draining Deep River valley and in Gardner Brook valley where they bury a former divide. Deltaic deposits north of Gardner Lake have surface altitudes of 405-415 ft (123-127 m) and were built into a small lake controlled by a 395-ft (120-m) spillway. Deltas in Deep River valley including one near-ice-marginal delta have surface altitudes of 425 ft (130 m) and were built into a small lake controlled by a 415-ft (127-m) spillway across the divide at The Wales. Slightly lower deltas on north side of Deep River Reservoir are extensively collapsed and were controlled by a 385-ft (117-m) spillway across deposits occupying the divide area north of Gardner Lake. |
| led |
LEDYARD DEPOSITS (Uncasville) IP-- Ice-marginal deltas in three north-draining tributaries to the Thames River. Deltas with surfaces at 165-185 ft (50-56 m) in Billings Avery Brook valley contain numerous well-developed kettles and were controlled by two spillways that cross the Ledyard Moraine (unit hlem) and the head of unit gr at 175 ft (53 m) and 155 ft (47 m). Deltas in Joe Clark and Shewville Brook valleys to the north were controlled by three local spillways at 175 ft (53 m), 155 ft (47 m) and 125 ft (38 m). |
| mr |
MIDDLE RIVER DEPOSITS (Monson, Stafford Springs) SP-- Ice-marginal deltaic and fluviodeltaic deposits ponded behind blockage in bedrock narrows at Stafford Springs village. Deltaic surfaces are at altitudes of 545 ft (166 m) at south end of unit; fluvial feeder deposits including eskers reach 605 ft (184 m) altitude in the tributary valley of Patten Brook and at the ice-marginal head just south of State Line Pond. Fluviodeltaic deposits extending into Massachusetts were ponded behind the 605-ft head (184-m). |
| bg |
BIGELOW BROOK DEPOSITS (Southbridge, Westford, Eastford) SP-- Ice-marginal deltaic deposits at south end of unit at 560 ft (171 m) altitude; ponded initially by deposits of unit p (ip) which blocked the valley. Terrace remnants at 615 ft (188 m) rise northward to an ice marginal position at 665 ft (203 m) in central part of unit; these deposits probably are mostly fluvial. Ice-marginal deltaic deposits with a long feeder-esker at north end of unit extend across divide into Quinebaug River basin. |
| sk |
SKUNGAMAUG RIVER DEPOSITS (Stafford Springs, South Coventry) SP-- Ice-marginal fluviodeltaic deposits built as two successive sequences in the southern half of the valley graded to a ponded level of about 485 ft (148 m); lake-bottom deposits at the southern end with a surface level of 450-460 ft (137-140 m); the valley was dammed probably by deposits of unit u in the valley narrows at the south end. Northern half of unit was ponded behind morainal deposits (unit em) a mile south of Tolland village. Deltaic surfaces are at 545 ft (166 m) in this section of the valley and fluvial deposits reach 575 ft (175 m) at the north end. Sandy surfaces at 510-520 ft (155-159 m) just north of the moraine are probably lake-bottom deposits. |
| hp |
HOP RIVER DEPOSITS (Columbia, Marlborough, Rockville) SP-- Succession of at least six ice-marginal deltaic morphosequences along the Hop River valley, though only two ice positions are clearly evident from surface morphology. Surface gradients rise from 295 ft (90 m) at east end of valley where deposits merge with those in the Willimantic valley, to 405 ft (123 m) in altitude to the west; this is an overall gradient of about 4 ft/mi (.8 m/km), some of which is postglacial rebound. |
| mf |
MOUNT HOPE AND FENTON RIVERS DEPOSITS (Spring Hill) SP-- Successive ice-marginal fluviodeltaic deposits along the two river valleys. The coarse gravelly terraces and the still coarser esker segments may be mostly fluvial with only minor deltaic sections; these deposits are almost certainly composite, but ice-contact heads are not clearly shown. At the south end of the unit, where the two valleys join in the Mansfield Hollow Lake area, an extensive deltaic deposit at 265 ft (81 m) altitude was dammed behind the northernmost ice-marginal head of unit wil. |
| na |
NATCHAUG RIVER DEPOSITS (Eastford, Hampton) SP-- Successive ice-marginal fluviodeltaic deposits in the Natchaug valley; ice-margin positions not clearly shown. Deltaic surfaces altitudes rise from 365 ft (111 m) at south end of unit to over 600 ft (183 m) at north end. This relatively steep gradient indicates that there is much fluvial deposition. |
| wru |
UPPER WILLIMANTIC RIVER DEPOSITS (Stafford Springs, South Coventry) SP-- Series of ice-marginal fluviodeltaic deposits in the narrow, steeper-gradient section of the upper Willimantic River valley. Ponding was initially behind the head of unit wrl at about 315 ft (96 m) in altitude; deltaic surfaces are as high as 415 ft (127 m) in north part of unit. |
| wrl |
WILLIMANTIC RIVER DEPOSITS (South Coventry, Columbia) SP-- Successive ice-marginal deltaic and fluviodeltaic deposits laid down in narrower section of Willimantic River valley behind the head of unit wil, related to at least two ice margin positions. Levels of ponding are slightly higher than in unit wil at 275 to 295 ft (84 to 90 m); fluvial feeder deposits reach 305 ft (93 m) altitude. |
| wil |
WILLIMANTIC-UPPER SHETUCKET DEPOSITS (Willimantic, Scotland, Spring Hill) SP-- Predominantly successive ice-marginal deltaic and fluviodeltaic deposits in the relatively wide, shallow-gradient section of the Shetucket River valley. The deposits are related to at least twelve ice-margin positions. Initial ponding was behind deposits of unit str and remnant ice blocks in the narrows of the Shetucket River at the south end of unit. Levels of successive ponding throughout the unit were at 235-255 ft (72-78 m); fluvial feeder deposits reach as high as 300 ft (91 m) in the lower Natchaug valley and the valley of Potash Brook. An ice-margin parallel ridge at the head of the first ice-marginal delta in this series is at 275 ft (84 m) in altitude, 50 ft (15 m) above the 235-ft (72-m) delta surface in front of it; this feature may quite possibly be a morainic ridge, but no gravel pits in which to observe its internal structure have yet become available. A relatively extensive meltwater terrace unit inset into deltaic surfaces at Windham record a 15-20 ft (5-6 m) drop in ponding level while meltwater still flowed down the Potash Brook valley. |
| lru |
UPPER LITTLE RIVER DEPOSITS (Hampton, Scotland) SP-- Ice-marginal deltaic and deltaic-fluvial deposits built at three southern ice positions; northernmost sequence is a near-ice-marginal fluviodeltaic deposit. Ponding in the south part was at 355-365 ft (108-111 m) initially behind head of unit lrl; fluvial deposits in the third sequence reach as high as 465 ft (142 m); the northern sequence ponded behind this head at 425-435 ft (130-133 m) has fluvial feeder deposits as high as 535 ft (163 m) at north end. |
| lrl |
LOWER LITTLE RIVER DEPOSITS (Scotland, Norwich) SP-- Ice-marginal deltaic-fluvial morphosequences in the south half of the Little River valley, related to at least three ice-margin positions. Initial ponding was at a level of 145-155 ft (44-47 m) behind deposits of unit str at Versailles; surface gradients rise steeply northward to 365 ft (111 m) at north end of unit; levels of ponding increase about 50 ft (15 m) between sequences because of relatively thick fluvial aggradation at each head. |
| mbb |
MERRICK, BEAVER, AND BALLYMAHACK BROOKS DEPOSITS (Spring Hill, Scotland, Willimantic, Hampton) SP-- Near-ice-marginal fluviodeltaic deposits in the three valleys with long fluvial sections of very coarse gravel; fluvial deposits are as high as 450 ft (137 m) and grade southward with 40-50 ft/mi (7.6-9.5 m/km) gradients to deltaic deposits at 225 ft (69 m) in altitude. Deltaic-fluvial deposits initially ponded against local divides at heads of Beaver and Merrick brooks, near the long feeder esker; fluvial aggradation continued across those divides. |
| str |
LOWER SHETUCKET RIVER DEPOSITS (Norwich, Fitchville, Willimantic) SP-- Successive ice-marginal deltaic deposits in the main Shetucket valley; ice-marginal and near-ice-marginal fluvial deposits in tributary valleys grade to deltas in the Shetucket valley and in Beaver Brook valley. Initial ponding was behind deposits of unit yr in the Thames valley; delta altitudes increase from 95 ft (29 m) at Taftville to 195 ft (59 m) at north end of the unit. |
| yr |
YANTIC RIVER DEPOSITS (Norwich, Fitchville) SP-- Ice-marginal deltas and fluviodeltaic deposits; near-ice-marginal fluvial deposits in tributary valleys are on grade to deltas in the main Yantic valley. Initial ponding was behind deltas of units lu and tc in Thames River valley; delta altitudes rise from 95 ft (29 m) at the Yantic River confluence with the Thames, to 175 ft (53 m) near the village of Fitchville. |
| tc |
TRADING COVE BROOK DEPOSITS (Fitchville, Norwich, Uncasville) SP-- Near-ice-marginal fluviodeltaic and ice-marginal deltaic deposits; initially ponded behind deposits of unit lu in Thames valley at Trading Cove. Fluvial deposits in tributary valleys of Ford, Gardner, and Great Plain Brooks are as high as 115 ft (35 m) and grade to delta surfaces in lower Trading Cove valley at 75-85 ft (23-26 m); northern part of unit consists of fluvial deposits as high as 235 ft (72 m) at north end that slope steeply to delta surface at 105 ft (32 m) behind the earlier ice-marginal deltas. |
| ox |
OXOBOXO DEPOSITS (Fitchville, Montville) SP-- Ice-marginal fluviodeltaic deposit in southeast end of unit and successive ice-marginal deltas in northwest part of Oxoboxo Brook valley. Proximal fluvial deposits at south end of Oxoboxo Lake, probably built at the Oxoboxo moraine position, are at 435 ft (133 m) slope down-valley with a surface gradient greater than 50 ft/mi (9.5 m/km) to deltaic deposits at 275 ft (84 m) behind bedrock narrows at south end of Wheeler Pond and head of unit lu. Ice-marginal deltas north of Oxoboxo Lake were ponded behind the 435-ft (133-m) fluvial deposits and have surface altitudes of 415-425 ft (127-130 m). |
| el |
EAST LYME DEPOSITS (Old Lyme, Niantic, Montville) SP-- Ice-marginal and near-ice-marginal fluviodeltaic deposits in the Fourmile River, Pataquanset River and Stony Brook valleys; ponding in each valley was initially behind deposits of unit Cni. Delta surface altitudes increase from 65 ft (20 m) to 135 ft (41 m) in the Fourmile River valley and from 45 ft (14 m) to 105 ft (32 m) in the Pataguanset valley and its tributaries Latimer Brook and Lakes Pond Brook; youngest deposits in this unit head at the Ledyard moraine (unit hlem). |
| sbp |
SHERMAN BROOK, BARTLETT BROOK, PEASE BROOK DEPOSITS (Colchester, Fitchville, Willimantic, Columbia) FP-- Ice Marginal and near-ice-marginal fluvial morphosequences in steep tributary valleys to the Yantic River; surface gradients are 40-50 ft/mi (7.6-9.5 m/km) and deposits are coarse gravel facies in most proximal parts. |
| jhg |
JORDAN BROOK, HUNTS BROOK, GREEN MARSH BROOK DEPOSITS (Montville, Uncasville, New London, Niantic) FP-- Ice-marginal fluvial deposits in steep sections of three valleys; shingled against proximal fluvial heads on unit Cjt in lower part of each valley. Surface gradients in each sequence are 40-50 ft/mi (7.6-9.5 m/km); first sequence in Hunts Brook valley heads at the Ledyard moraine (unit hlem) and the sequence in Jordan Brook valley is near-ice-marginal built from Ledyard moraine position on upland about .25 mi (0.4 km) to north of unit. |
| gr |
GROTON DEPOSITS (Uncasville, New London) FP-- Ice-marginal fluvial deposits in steep upper sections of tributary valleys to the Poquonnock River; the head of outwash in the Hempstead Brook valley lies on the northern divide at 115 ft (35 m) altitude and slopes southward at about 40 ft/mi (7.6 m/km); it is shingled against an ice-marginal fluvial head of unit Cp. Deposits in the Rosemond Lake valley head at the Ledyard moraine (unit hlem), also at the northern divide at 195 ft (59 m) and slope southward with a gradient of about 25 ft/mi (4.8 m/km) to 105 ft (32 m), shingled against the 135-ft (41 m) head of unit Cp in that valley. |
