Artificial fill-Earth and manmade materials including rocks, gravel, sand, silt, clay, concrete, and select refuse artificially and extensively emplaced, principally in coastal areas. Highway and railroad fill, areas of landfills, and local fill in urban areas are not mapped.

Flood-plain alluvium - Sand, gravel, silt, minor clay, and some organic material in flood plains of modern streams. Along smaller streams, texture of alluvium is commonly variable both laterally and vertically, but overall texture is often similar to adjacent glacial materials. Thickness commonly less than 2 m (6 ft). Along larger rivers, contains gravel and sand at base, overlain by laminated sand, silt, and minor clay, as much as 8 m (25 ft) thick. Alluvium of Connecticut River north of Rocky Hill is chiefly very fine sand and silt, less than 5 m (18 ft) thick. Along Connecticut River south of Rocky Hill, alluvium is chiefly fine to medium sand, as much as 12 m (40 ft) thick. Alluvium overlies glacial stratified sand and gravel, coarse gravel, or till in upland valleys; in lowlands, commonly overlies sand or silty-clayey lake-bottom deposits

Swamp deposits-Muck and peat that contain minor amounts of sand, silt, and clay overlying laminated organic silt, clay, and sand. Organic peat and muck is decomposed, fibrous and granular, woody herbaceous material. Thickness of organic materials is commonly less than 3 m (10 ft). Some deposits accumulated in poorly drained areas, mostly in shallow, low-lying basins in till and (or) bedrock areas; other deposits accumulated in relatively deep, closed depressions (kettles) in ice-proximal, glacial meltwater deposits, and in shallower depressions and swales on glacial lake-bottom surfaces; some deposits occupy low swales between alluvial levees on Holocene flood-plain surfaces. Thicker peat and muck deposits (for example, 4 m (13 ft) at Totoket bog, a kettle-hole swamp just north of Route 80 and west of Bare Plain cemetery in the village of Totoket in the Branford quadrangle; 10 to 14 m (33 to 46 ft) beneath Linsley Pond and Cedar Pond in North Branford; 11 m (36 ft) beneath Rogers Lake in Lyme; and 4 m (13 ft) at Durham Meadows) preserve a record of vegetation changes and hence a paleoclimatic record for postglacial time. Oldest postglacial radiocarbon dates in Connecticut (~15 ka) come from base of organic swamp deposits at Totoket bog and Rogers Lake. Generally overlie materials of adjacent map unit. Shown only where greater than 25 acres in area

Tidal-marsh deposits - Peat and muck, generally 1 to 9 m (3 to 30 ft) thick, interbedded at depth with laminated fine sand and silt. Organic peat and muck is decomposed, fibrous and matted, herbaceous and silty-herbaceous material that accumulated in marshes at and upstream from mouths of streams open to marine waters of Long Island Sound; marshes include coastal salt marshes and brackish to freshwater tidal marshes farther up estuaries. Vegetation growing today in tidal marshes as well as plants preserved in peat deposits ranges from salt-water species (such as Spartina alterniflora and S. patens) to species tolerant to brackish water (such as Typha angustiflora and Phragmites australis) to freshwater sedge and rush species (such as Scirpus fluviatilus, Juncas accumintus, and Pontederia cordata). Vertical accretion and upstream (northward) transgression through time records drowning of former alluvial terraces along coastal streams during postglacial sea-level rise. Basal portion of most of the tidal-marsh deposits shown on map lies on surfaces above -5 m (-15 ft) mean sea level (MSL); a sea-level-rise curve generated from radiocarbon dates from tidal-marsh peat deposits along lower Connecticut River (Patton and Horne, 1991) indicates marine transgression beginning 4,000 years ago. In some places, such as marsh along Hammock River in Clinton, salt-marsh peat overlies estuarine deposits; these peat deposits are composed of organic sand and silt and freshwater sedge peat at depths of up to -12 m (-40 ft) MSL, which yield older radiocarbon dates that indicate a marine transgression beginning 7,000 years ago (Bloom and Stuiver, 1963; van de Plassche and others, 1989). Shown only where greater than 25 acres in area 

Talus - Angular, loose blocks of basalt and diabase accumulated by rockfall and creep at base of bedrock cliffs along linear traprock ridges in Central Lowland. Forms steep unstable slopes. Generally less than 6 m (20 ft) thick 

Coastal beach and dune deposits - Fine to coarse sand and local pebble-cobble gravel in modern beach deposits. Texture of beach deposits varies over short distances and is generally controlled by texture of nearby glacial materials exposed to wave action. Beach deposits are poorly to well sorted and enerally less than 2 m (6 ft) thick. Locally includes dune deposits consisting of relatively well sorted, fine to coarse sand in transverse coastal eolian dunes that are 1 to 3 m (3 to 10 ft) thick 

Stream-terrace deposits - Sand, gravel, and silt deposited by meteoric water on terraces that were cut into glacial meltwater sediments. Texture is variable vertically and laterally, but is chiefly coarse pebbly sand, commonly similar to that of adjacent glacial deposits. Thickness ranges from 1 to 5 m (3 to 15 ft). Distinguished from meltwater-terrace deposition by its lower position in valley, commonly only 3 to 6 m (10 to 20 ft) above altitude of modern flood plains

Medium, relatively well sorted sand, in transverse, parabolic, and hummocky dunes as much as 12 m (40 ft) thick. Most common in drained basin of glacial Lake Hitchcock where sand was derived from extensive glacial-lake deltaic deposits. Dunes overlying lake-bottom deposits of glacial Lake Middletown and early phase of glacial Lake Hitchcock indicate predominant north-northeast wind direction in early postglacial time. Dunes overlying lake-bottom deposits and stream-terrace deposits in glacial Lake Hitchcock basin indicate predominant north-northwest wind direction after lake drainage; major dune fields cover lake-bottom surface on east side of valley. Dune sand now fixed by vegetation except where disturbed by human activities. Eolian silty sand, generally less than 1 m (3 ft) thick, is widespread in valleys and lower till slopes, but is not shown on map

Uncorrelated Meltwater Deposits  - Sand, gravel, silt, and clay deposited in unidentified systems. Most appear to be ice-contact deposits entirely on glacial ice and collapsed down to present positions in landscape. Locally includes lake-bottom deposits (ruled pattern) that cannot be associated with any particular glacial lake 

Glacial Lake Norfolk deposits - Ice-marginal deltaic deposits and lake-bottom deposits in north-west-sloping Blackberry River valley. Deltas record lake levels in two stages. Deltaic deposits at Norfolk with surface altitude of 410 m (1,345 ft) were controlled by a spillway at 404 m (1,325 ft) across Housatonic and Naugatuck Rivers drainage divide. Ice-marginal deltaic deposits at East Canaan with surface altitudes at 270 m (885 ft) and topset-foreset contacts at about 265 m (870 ft) were controlled by 261-m (855-ft) spillway to northwest around northern end of Canaan Mountain. (Ashley Falls, South Sandisfield, Norfolk)

Glacial Lake Cornwall deposits - Deposits in southern part of unit indicate either highly collapsed ice-marginal deltas or (more likely) ice-marginal lacustrine fans that did not build up to lake level. Surface altitudes are well below 337-m (1,105-ft) col across southern divide of Valley Brook. Northern deposits include small ice-marginal deltas built into lake from Baldwin Brook and Bloody Brook valleys at three levels: 261 m (855 ft), 230 m (755 ft), and 215 m (705 ft); highest level probably was controlled by 258-m (845-ft) spillway high on southern side of Furnace Brook valley, while ice margin blocked drainage. Lower two levels must have been controlled by ice or till blockage in Furnace Brook valley. Thick lake-bottom deposits occur beneath and in front of 215-m (705-ft) deltaic deposits in Cornwall village. (Cornwall)

Glacial Lake Hollenbeck deposits - Ice-marginal deltaic and lacustrine fan deposits and lake-bottom deposits in northwest-sloping Hollenbeck River valley. Successive ice-marginal deltas with narrow, ridge-like forms at southern end of lake are at 300 to 303 m (985 to 995 ft) and were controlled by 297-m (975-ft) spillway across divide at southern end of valley. To the north, successive ice-marginal lacustrine fan deposits are at lower than lake-level altitudes; in several exposures, internal bedding of these sediments displays severe, active ice deformation. Later lake stages were controlled by spillways at 215 m (705 ft) and 203 m (665 ft) west of Cobble Mountain. (South Canaan, Cornwall)

Glacial Lake Danbury, Pumpkin Hill stage deposits - Glacial Lake Danbury was dammed by northerly retreating ice margin in north-sloping Still River valley. Lake had three stages controlled in level by three successively lower spillways. Pumpkin Hill stage deposits - One ice-marginal delta at 114 m (375 ft), controlled by short-lived 114-m (375-ft) spillway across northern end of Pumpkin Hill, adjacent to junction of Still River valley with Housatonic River valley. More extensive ice-marginal deltaic deposits at 90 to 93 m (295 to 305 ft) were graded to last stage of glacial Lake Danbury and controlled by 90-m (295-ft) spillway about 305 m (1,000 ft) farther north on Pumpkin Hill. Narrow bedrock gorge of Housatonic River just downstream from spillway must have been temporarily blocked to permit use of Pumpkin Hill spillway during ice retreat for about 3 km (2 mi) north of gorge. (New Milford)

Glacial Lake Danbury, Pond Brook stage deposits - Glacial Lake Danbury was dammed by northerly retreating ice margin in north-sloping Still River valley. Lake had three stages controlled in level by three successively lower spillways. Pond Brook stage deposits - Ice-marginal and near-ice-marginal deltaic deposits, esker-fed lacustrine fan deposits, and associated lake-bottom sediments. Near-ice-marginal deltas south of Lake Candlewood have surface altitudes of 126 to 130 m (415 to 425 ft); inset against these is a delta at 114 to 117 m (375 to 385 ft) that was fed by distal meltwater from Lake Candlewood valley. Ice-marginal delta deposits just west of spillway are at 120 to 123 m (395 to 405 ft); other ice-marginal deposits are lacustrine fans that did not build up to lake level. This stage of glacial Lake Danbury was controlled by spillspillway eastward into Pond Brook valley that began initially at about 126 m (415 ft) and was incised down to about 114 m (375 ft) during time of its use. (Danbury, New Milford)

Glacial Lake Danbury, Saugatuck divide stage deposits - Glacial Lake Danbury was dammed by northerly retreating ice margin in north-sloping Still River valley. Lake had three stages controlled in level by three successively lower spillways. Saugatuck divide stage deposits - Ice-marginal deltas, fluviodeltaic deposits, and associated lake-bottom sediments. Delta surfaces have altitudes of 136 to 139 m (445 to 455 ft); fluvial feeders reach 154 m (505 ft). This stage of glacial Lake Danbury was controlled in level by 127-m (415ft) spillway south into Saugatuck River valley. (Danbury, Bethel)

Glacial Lake Pootatuck deposits - Successive ice-marginal deltaic deposits in north-draining Pootatuck River valley; near-ice-marginal fluviodeltaic deposits in upper valley. Deltas at 133 to 139 m (435 to 455 ft) in southern part of unit were graded to 130-m (425-ft) and 133-m (435ft) spillways across southern divide. Ice-mar-ginal deltas in Berkshire village at 117 to 120 m (385 to 395 ft) were graded to 114-m (375-ft) spillway to the east; northernmost ice-marginal deltas at 102 to 105 m (335 to 345 ft) were controlled by spillway across Berkshire deltas northward into Pole Bridge Brook valley; floor of this spillway is now at 96 m (315 ft) but was initially 3 to 6 m (10 to 20 ft) higher. (Newtown, Botsford)

Glacial Lake Winsted deposits - Ice-marginal deltas and fluviodeltaic deposits. Deltas have surface altitudes at 224 to 230 m (735 to 755 ft); extensive fluvial deposits in main valley reach 239 m (785 ft) and in tributary valleys are as high as 274 m (900 ft). Lake was ponded in north-draining Still River valley and controlled in level by three spillways. First was at 224 m (735 ft) and spilled into Naugatuck River valley. Next two successive spillways near Winsted drained into Farmington River valley. These spillways now are at 227 m (745 ft), but were 6 to 9 m (20 to 30 ft) lower relative to the first one before postglacial tilting. (Winsted, Torrington)

Glacial Lake Nepaug deposits - Ice-marginal deltas in lower (eastern) part of Nepaug River valley and near-ice-marginal deltaic deposits in upper valley. Both sets of deltas record two lake levels. Deltas with surfaces at 215 to 224 m (705 to 735 ft) were graded to lake levels controlled first by 218-m (715-ft) and then 212-m (695-ft) spillway on till-blanketed hillside south of Nepaug Reservoir. Deltas with surfaces at 200 to 203 m (655 to 665 ft) are inset into higher level deltas in upper valley and easterly against higher deltas in lower valley; they were controlled by 191-m (625-ft) spillway downslope from first spillways. Glacial Lake Nepaug was contained in inter-lobate angle between Connecticut Valley ice lobe and western upland ice margin; valley ice-dammed lake and ice-marginal deltas in lower Nepaug River valley were built against it; upland ice margin provided meltwater and sediment to build deltaic deposits in upper valley. Lake lowered as valley ice retreated eastward off hillside south of present Nepaug Reservoir. (Collinsville, Torrington)

Glacial Lake Bristol deposits - Ice-marginal deltaic and fluviodeltaic deposits in upper Pequabuck River valley and its northern tributaries. Deltas with surfaces at 197 to 200 m (645 to 655 ft) near Terryville controlled by 194-m (635-ft) spillway across Naugatuck River-Farmington River-Quinnipiac River divide. Fluvial feeder deposits as high as 248 m (815 ft) in upper Poland River valley built from upland ice-mar-gin positions and graded to deltas at Terryville. Ice-marginal deltaic deposits in northeastern part of unit were built from ice positions to the northwest and were probably controlled by separate local spillway at 209 m (685 ft). Glacial Lake Bristol was contained in an interlobate angle between Connecticut Valley ice lobe and western upland ice margin. Pequabuck River valley was dammed to very high levels against drainage divide by thick valley lobe ice; ice-marginal deltas were built into lake from lobe ice position; at same time, fluviodeltaic deposits were built into lake from ice to northwest. (Bristol, Thomaston, Collinsville)

Glacial Lake Coginchaug, Middletown stage deposits - Deposits in lower Coginchaug River and Sumner Brook valleys consist of small ice-marginal deltas, mostly collapsed; narrow noncollapsed fringes of these deltas occur at 81 m (265 ft), 69 m (225 ft), and 56 to 59 m (185 to 195 ft) built into successively lower levels of this stage, controlled by three spillways across rock ridge west of Sumner Brook at 75 m (245 ft), 59 m (195 ft), and 53 m (175 ft). Valley of Sumner Brook also was ponded, spilling out via two successive spillways east of valley at 59 m (195 ft) and 53 m (175 ft). Only a few small deposits at this level exist in Sumner Brook valley. Lake-bottom deposits in Sumner Brook may have accumulated, in part, in glacial Lake Middletown, which succeeded glacial Lake Coginchaug in this valley at lower level. (Middletown, Durham)

Glacial Lake Coginchaug, Durham stage deposits - In upper Coginchaug River valley, ice-marginal deltas, and ice-marginal and near-ice-marginal fluviodeltaic deposits built by meltwater from tributary valleys. Delta surfaces are at 87 m (285 ft) at southern end of basin and 93 m (305 ft) at northern end. All deposits except very earliest were graded to 84-m (275 ft) spillway across southern Coginchaug River drainage divide. Lake-bottom sediments occur in three areas; largest body, beneath Durham Meadows, may have accumulated mostly during Middletown stage. (Durham, Middletown)

Glacial Lake Manchester deposits - Predominantly ice-marginal deltaic deposits graded to long, narrow lake between Connecticut Valley ice lobe and upland till slope in south-central Manchester. Two stages of lake were controlled by spillways between bedrock hills; earlier stage with delta surfaces at 84 to 99 m (275 to 325 ft) was controlled by 81-m (265-ft) spillway; later stage delta surfaces are at 66 to 78 m (215 to 255 ft) controlled by 66-m (215-ft) spillway. (Manchester, Rockville)

Glacial Lake Salmon Brook deposits - Ice-marginal deltaic and fluviodeltaic deposits graded to two stages of long narrow lake initially in Salmon Brook valley, southwestern end of which was dammed by Connecticut Valley ice lobe, and then to the north in southeastern part of city of Manchester. In Salmon Brook valley, fluvial surfaces as high as 96 m (315 ft) grade southwestward to deltas at 81 m (265 ft) controlled by 75-m (245-ft) spillway between two drumlin hills. Ice-marginal deltaic deposits in Manchester have surfaces at 99 m (325 ft) and were controlled by two spillways: one over older 96-m (315-ft) surface has present altitude of 87 m (285 ft), and the other at 87 m (285 ft) between bedrock hills north of Salmon Brook valley. (Glastonbury, Manchester)

Glacial Lake Roaring Brook deposits - Ice-marginal deltaic and fluviodeltaic deposits graded to three stages of long, narrow lake in Roaring Brook Valley, southwestern end of which was blocked by Connecticut Valley ice lobe. Ice-marginal deltaic deposits with 136- to 139-m (445- to 455-ft) surfaces on southeastern side of Roaring Brook valley, graded to 126-m (415-ft) spillway. Fluvial deposits that head west of Minnechaug Mountain, north of valley, are at 130 m (425 ft) and grade southwestward into valley to deltas with surfaces at 111 to 114 m (365 to 375 ft), controlled by 105-m (345-ft) spillway. Predominantly deltaic deposits with surfaces at 108 to 114 m (355 to 375 ft) west of Minnechaug Mountain were graded to 105-m (345-ft) spillway across older deposits; meltwater from this spillway entrenched and terraced older 111- to 123-m (365- to 405-ft) surfaces and constructed deltas at southern end of unit with surfaces at 87 to 93 m (285 to 305 ft), controlled by 87-m (285-ft) spillway. (Glastonbury, Rockville)

Glacial Lake Colchester deposits - Successive ice-marginal deltas with surface altitudes of 114 to 120 m (375 to 395 ft) deposited in earlier stage of lake in Nelkin Brook and Meadow Brook valleys. Spillway across Colchester deposits (lc) began at about 117 ft (385 ft) and eroded down to bedrock at 111 m (365 ft). Ice-marginal deltas built into later stage of lake in Judd Brook and Raymond Brook valleys have surfaces at 120 to 130 m (395 to 425 ft); controlled by spillway at 114 m (375 ft). Meltwater flow across spillway eroded last delta of older stage of lake, because older stage drained while younger stage still existed. (Colchester)

Glacial Lake Essex deposits - Four small ice-marginal deltas graded to four early-stage spillways across southern Falls River drainage divide; ice-marginal fluviodeltaic deposits in Falls River valley and northern tributaries. Fluvial feeder deposits reach 35 m (115 ft) and grade to deltaic surfaces in Centerbrook at 11 to 14 m (35 to 45 ft); controlled by spillway at southern part of Essex village at 11 m (35 ft). Early ice-marginal deltas probably built at nearly same time, while ice still occupied Falls River valley. When Falls River valley was uncovered, ice margin continued to block mouth of valley north of Essex village, creating main part of lake basin. (Essex, Deep River)

Glacial Lake Oneco deposits - Successive ice-marginal deltaic deposits in Moosup River valley and ice-marginal and near-ice-marginal fluviodeltaic deposits in northern tributary valleys, some of which are in Rhode Island. A free-front delta at Oneco with lake-bottom sediments in front of it was built westward into lake fed by ice-marginal fluvial deposits farther upstream in Moosup River valley in Rhode Island. Ice-marginal fluvial deposits in Quanduck Brook valley are at 169 m (555 ft) and grade southward on steep gradient to 123- to 126-m (405- to 415ft) deltas built into lake. Lake was dammed by ice margin in west-northwest-draining Moosup River valley and was controlled by three spillways. Highest spillway at 114 m (375 ft) is just over border in Rhode Island as are the deltas it controlled; a lower spillway that controlled most deposits in Connecticut crosses Quinebaug River-Pawcatuck River divide at 111 m (365 ft). A 108-m (355-ft) notch cut into a thick till hillside at last ice-margin position may have controlled level of lake for a short period of time before further ice retreat caused lake to empty. (Oneco)

Glacial Lake Voluntown deposits - Successive ice-marginal deltas related to at least seven ice-margin positions. Several esker-fed lacustrine fan deposits that did not quite build up to lake level occur in central part of lake basin. Lake-bottom deposits exist at surface in few small areas that remained as open water. Lake existed in three stages, controlled by successive spillways at 123 m (405 ft), 111 m (365 ft), and 102 m (335 ft) across Quinebaug River-Pawcatuck River divide. (Voluntown) 

Glacial Lake Pachaug deposits - Predominantly successive ice-marginal deltas in Pachaug River basin including some esker-fed deltas. Lake-bottom sediments underlie meltwater-terrace deposits in central part of basin and probably occur beneath Pachaug Pond as well. Ice-marginal fluviodeltaic deposits occur as one morphosequence in northeastern part of unit. Deposits are related to at least 10 ice-margin positions. Glacial Lake Pachaug existed in three successively lower stages controlled by spillways across divide on western side of basin. Earliest delta was built into highest stage controlled by 72-m (235-ft) spillway when ice margin was at southern end of basin. Several succeeding deltas were deposited in second stage of lake controlled by 69-m (225-ft) spillway. Last and longest-lived stage of lake controlled by 59-m (195-ft) spillway is recorded by deltas built at six successively northward ice-margin positions. Further ice retreat caused glacial Lake Pachaug to drain westward into Quinebaug valley and caused water levels to lower to altitude of glacial Lake Quinebaug. (Jewett City)

Glacial Lake Great Falls deposits - Ice-marginal deltaic deposits and extensive lake-bottom sediments in Housatonic River valley from Great Falls northward into Massachusetts. Ice-marginal deltas are at 206 to 209 m (675 to 685 ft) near Canaan village. Lake-bottom deposits are as much as 30 to 61 m (100 to 200 ft) thick in overdeepened bedrock basin in easily erodible marble. Spillway was lip of modern Great Falls, initially perhaps 3 to 5 m (10 to 15 ft) higher than present 192-m (630-ft) level. Lake extended northward into Massachusetts. (Ashley Falls, South Canaan)

Glacial Lake Lime Rock deposits - Ice-marginal deltas with surfaces at 181 to 187 m (595 to 615 ft) and lake-bottom sediments built into small lake at junction of Salmon Creek valley with Housatonic River valley. Lake was dammed behind ice-contact head of Housatonic River deposits (hrn); spillway across Housatonic River was removed by postglacial incision of river. (South Canaan, Sharon)

Glacial Lake Kenosia deposits - Extensive lake-bottom deposits at lower end; delta rises west to ice-contact head just across State line in New York. Water from this lake eroded thick till along Still River and spilled into glacial Lake Danbury. (Brewster, Danbury)

Glacial Lake Bantam deposits - Ice-marginal and near-ice-marginal deltas with surfaces at 276 to 282 m (905 to 925 ft). Initial spillway at 276 m (905 ft) across divide at southern end of present Bantam Lake; later control of glacial lake level was across till surface at present lake outlet. Basin in which glacial lake existed and in which modern lake remains formed by deposition of extensive thick till in Litchfield drumlin field. (Litchfield)

Glacial Lake Pomperaug deposits - Ice-marginal deltaic and fluviodeltaic deposits, near-ice-marginal fluviodeltaic deposits, and associated lake-bottom sediments. Successive ice-marginal deltaic and fluviodeltaic deposits in southern part of unit have surface altitudes of 78 to 81 m (255 to 265 ft). Initial ponding was behind Housatonic River deposits (hrs); spillway across those deposits was incised from about 72 m (235 ft) to 66 m (215 ft). Northern part of unit consists largely of fluviodeltaic deposits; long fluvial feeder deposits reach 154 m (505 ft) in Weekeepeemee River valley and 123 m (405 ft) in Nonewaug River and Sprain Brook valleys and grade to deltaic deposits at Woodbury with surface altitudes of 87 to 96 m (285 to 315 ft). This later lake drainage spilled across earlier deposits at Pomperaug village and may have finally stabilized in bedrock spillway at 78 m (255 ft). (Woodbury, Southbury)

Glacial Lake Tariffville deposits - Deltaic deposits overlying lake-bottom sediments more than 30 m (100 ft) thick in lower Salmon Brook valley. Ice-marginal fluvial deposits at Goodrichville reach 84 m (275 ft) and are on grade with deltaic surfaces to the south at 75 m (245 ft). West of Manitook Mountain, highly collapsed ice-marginal deposits grade to delta surfaces as high as 84 m (275 ft) that contain as much as 9 m (30 ft) of topset beds. Level of glacial Lake Tariffville was controlled at Farmington River gap through Talcott Mountain and was most likely water plane of glacial Lakes Middletown and Hitchcock to the east. Some slightly lower surfaces at 59 to 66 m (195 to 215 ft) are terraces or inset deltas graded to lowering water levels in glacial Lake Hitchcock. (Tariffville)

Glacial Lake Farmington deposits - Ice-marginal fluviodeltaic deposits in Roaring Brook valley near Unionville and west of Farmington River in Avon. Fluvial surfaces reach 93 m (305 ft) and are on grade southward to deltaic surfaces at 81 to 84 m (265 to 275 ft) at Unionville and 78 to 81 m (255 to 265 ft) in Farmington. Deposits east of Farmington River in Avon are successive ice-marginal deltas with several feeder eskers; deltaic surfaces are at 84 to 87 m (275 to 285 ft). South of Farmington River, fluviodeltaic deposits were built against tongue of ice in valley; deltaic surfaces are at 72 m (235 ft), and fronts of these deltas were erosionally trimmed by later meltwater that deposited Quinnipiac River valley terrace deposits (qt) in central portions of valley. Distal lacustrine sand containing climbing ripples that indicate northward current directions can be seen in several places beneath unit qt; this material was supplied to lake by meltwater from Pequabuck River valley carrying sediment derived from crystalline rock. Spillway for this lake was initially across till deposits incised from about 67 m (220 ft) to 58 m (190 ft); subsequent melting of buried ice in Quinnipiac River valley and lowering of glacial Lake Southington caused outlet to switch positions so that spillway was across deposits of glacial Lake Southington (ls). (New Britain, Bristol, Avon, Collinsville)

Glacial Lake Southington deposits - Successive ice-marginal esker-fed deltas in Quinnipiac River valley, each of which has a collapsed proximal head on northern side and free-front delta slopes on southern side. Lake-bottom sediments occur in front of each delta. In western tributary valley, single ice-marginal fluviodeltaic deposit occurs with lake-bottom sediments at southern end. Delta topset-foreset contacts in towns of Cheshire and Southington occur at 59 to 60 m (193 to 196 ft), and indicate spillway at about 56 m (185 ft) over blocking material near present Quinnipiac Gorge. Quinnipiac River-Mill River deposits (qm) occur at 58 m (190 ft) on both sides of Quinnipiac River immediately west of gorge and provided some blockage to dam the lake. Gorge probably was blocked with thick deposits of till; however, it is possible that bedrock gorge did not yet exist and was carved by water spilling from glacial Lake Southington and succeeding lakes to the north. (Southington, Meriden, Bristol, New Britain)

Glacial Lake Quinnipiac deposits - Consists of an extensive delta in North Haven and small area of lake-bottom sediments exposed by clay pit operations. Entire lower Quinnipiac River valley from north of Fair Haven to South Meriden contains lacustrine deposits of glacial Lake Quinnipiac in subsurface, beneath extensive Quinnipiac River valley fluvial terrace deposits (qt); lacustrine deposits consist principally of varved silt and clay (New Haven clay of Flint, 1933) as much as 49 m (160 ft) thick. Delta at North Haven has ice-margin position on its north side, but foreset dip directions indicate that it was built mainly from meltwater coming from the northeast down Muddy River valley. Topset-foreset contacts (Lougee, 1938) in this delta indicate a 9- to 11-m (30- to 35-ft) altitude water plane at Fair Haven where glacial Lake Quinnipiac spilled across lobe of New Haven delta plain (lcnh), which had built out across former Quinnipiac River channel and blocked valley. New Haven delta acted as sediment dam to impound glacial Lake Quinnipiac above level of glacial Lake Connecticut during construction of Muddy River delta. Water spilling from glacial Lake Quinnipiac probably fairly quickly incised dam to level of glacial Lake Connecticut to the south; however, no exposed deltas exist to the north of Muddy River delta to record lower lake levels. (Branford, New Haven, Wallingford)

Glacial Lake Hitchcock, Beach deposits - Terrace-like deposits of sand on eastern shore of glacial Lake Hitchcock, ranging from 35 m (115 ft) in the south to 44 m (145 ft) in the north. These altitudes project to stable 25-m (82-ft) level of lake; some areas of beach deposits show slightly higher levels up-slope to the east. (Broad Brook, Manchester)

Glacial Lake Hitchcock, Lake-bottom deposits - Varved silts and clays in couplets ranging from 1 to 4 cm (0.4 to 1.6 in) thick and probably representing annual deposition. Well logs indicate that silt-clay couplets are thicker and red in color in lower part of section; these are overlain by alternating red and gray sediments; silt-clay couplets are thinnest in upper part of section and are gray. Numerous surface exposures indicate that top 2 to 3 m (6 to 10 ft) of section consists of thinly bedded silt and fine sand of sandy lake-bottom facies. Deposits are areally extensive and commonly greater than 15 m (50 ft) thick, as much as 80 m (260 ft) thick in some places

Glacial Lake Hitchcock, high-level, Windsor deltaic deposits - Ice-marginal deltas and fluviodeltas, distal-meltwater-fed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). Windsor deltaic deposits - Ice-marginal deltaic deposits in northeastern part of unit with surfaces at 59 to 61 m (195 to 200 ft); topset-foreset contact at 54 m (178 ft) (projects to NBS at 35 m (114 ft)). Deltaic deposits in southwestern part of unit with surfaces at 50 to 56 m (165 to 185 ft) were fed by distal meltwater; sediment was supplied to lake by early Farmington River-Salmon Brook meltwater drainage eastward through Tariffville Gap. (Windsor Locks, Hartford North)

Glacial Lake Hitchcock, high-level, East Windsor fluviodeltaic deposits  - Ice-marginal deltas and fluviodeltas, distal-meltwater-fed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). East Windsor fluviodeltaic deposits - Highly collapsed fluvial deposits with remnant surfaces as high as 69 to 72 m (225 to 235 ft) in northern part of unit grade southward along ice-margin position to deltaic deposits at 53 to 56 m (175 to 185 ft) in southern part of unit. (Broad Brook)

Glacial Lake Hitchcock, High-level Hockanum River delta deposits - Ice-marginal deltas and fluviodeltas, distal-meltwater-fed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). High-level Hockanum River delta deposits - Small delta with surface at 38 to 41 m (125 to 135 ft) and topset-foreset contact about 35 m (115 ft) (projects to NBS at 32 m (104 ft)); built by meteoric water in Hockanum River and Hop Brook valleys. (Manchester)

Glacial Lake Hitchcock, High-level Scantic River delta deposits - Ice-marginal deltas and fluviodeltas, distal-meltwater-fed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). High-level Scantic River delta deposits - Ice-marginal delta with surface at 59 to 62 m (195 to 205 ft) in southern part of unit. Distal-meltwater-fed delta with surfaces at 56 to 59 m (185 to 195 ft) in northern part of unit. (Broad Brook)

Glacial Lake Hitchcock, high-level, Rattlesnake Brook deltaic deposits - Ice-marginal deltas and fluviodeltas, distal-meltwater-fed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). Rattlesnake Brook deltaic deposits - Ice-marginal deltas with surfaces at 59 to 62 m (195 to 205 ft). (West Springfield, Windsor Locks)

Glacial Lake Hitchcock, high-level, Shea Corner deltaic deposits - Ice-marginal deltas and fluviodeltas, distal-meltwater-fed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). Shea Corner deltaic deposits - Ice-marginal deltaic deposits that extend into Massachusetts. Surfaces at 59 to 62 m (195 to 205 ft). (West Springfield)

Glacial Lake Hitchcock, high-level, Enfield deltaic deposits - Ice-marginal deltas and fluviodeltas, distal-meltwater-fed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). Enfield deltaic deposits - Deltaic deposits with surfaces at 59 to 62 m (195 to 205 ft) are distal parts of fluviodeltaic deposits built from ice-margin position north of map area in Massachusetts. Estimated lake level of 58 m (190 ft) (projects to NBS at 30 m (99 ft)). (Springfield South)

Glacial Lake Hitchcock, high-level, Ice-hole deposits - Ice-marginal deltas and fluviodeltas, distal-meltwa-terfed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). Ice-hole deposits - Collapsed, ice-contact sand and gravel deposits that encircle hills (mostly drumlins) which were islands in glacial Lake Hitchcock. As ice margin in lake thinned and melted away from island hillsides, deposits probably fed by subglacial meltwater streams accumulated in ice-walled depressions around drumlin hillsides. Glacial Lake Hitchcock water levels apparently controlled altitude of these deposits, because none were built to higher levels. (West Springfield, Hartford North, Manchester)

Glacial Lake Hitchcock, high-level, Spit deposits - Ice-marginal deltas and fluviodeltas, distal-meltwater-fed deltas, and a meteoric-water-fed delta. Delta altitudes adjusted for glacio-isostatic tilting and projected to New Britain spillway (NBS) record early lake levels from 35 m (115 ft) to about 29 m (95 ft). Spit deposits - Northeast-trending spits composed of southwest-dipping sandy foreset beds on southwestern ends of drumlin islands; generally smaller in size on drumlins lacking ice-hole deposit collar and larger in size on those that have it. Spits were built by waves and currents generated by early paleowinds from the northeast when ice margin was still nearby. (West Springfield, Windsor Locks, Broad Brook, Hartford North, Manchester)

Glacial Lake Hitchcock, stable-level, Bradley International Airport delta deposits - Meteoric-water-fed deltas and extensive lake-bottom deposits. Delta altitudes, when adjusted for glacio-isostatic tilting and projected to NBS, record 25-m (82-ft) stable lake level that began when ice margin was in southern Massachusetts. Bradley International Airport delta deposits - Large delta built by meteoric water from Farmington River valley that flowed through Tariffville Gap and discharged northeastward into glacial Lake Hitchcock. Delta probably is complex; in places in subsurface, older foreset beds built by distal meltwater from Farmington River valley into higher lake levels may lie beneath present delta surface. Delta surface slopes from 56 m (185 ft) in southwest to 47 m (155 ft) in the north and east. Topset-foreset contact at 47 m (154 ft) (projects to NBS at 25 m (82 ft)). (Windsor Locks)

Glacial Lake Hitchcock, Stable-level Scantic River and Broad Brook delta deposits - Meteoric-water-fed deltas and extensive lake-bottom deposits. Delta altitudes, when adjusted for glacio-isostatic tilting and projected to NBS, record 25-m (82-ft) stable lake level that began when ice margin was in southern Massachusetts. Stable-level Scantic River and Broad Brook delta deposits - Small deltas with surfaces at 47 to 50 m (155 to 165 ft) built by meteoric water in Scantic River and Broad Brook valleys as it entrenched high-level deposits and entered lower lake level. (Broad Brook)

Glacial Lake Hitchcock, Stable-level Hockanum River delta deposits - Meteoric-water-fed deltas and extensive lake-bottom deposits. Delta altitudes, when adjusted for glacio-isostatic tilting and projected to NBS, record 25-m (82-ft) stable lake level that began when ice margin was in southern Massachusetts. Stable-level Hockanum River delta deposits - Small delta with surface at 32 to 35 m (105 to 115 ft) built by meteoric water in Hockanum River and Hop Brook valleys as it entrenched deposits of the high-level Hockanum River delta deposits (lhhh) and entered lower level lake. (Manchester)

Glacial Lake Hitchcock post-stable-level Farmington River delta deposits - Meteoric-water-fed delta with surface altitude of 41 m (135 ft) and topset-foreset contact at 39 m (127 ft); this altitude projects to NBS at 21 m (70 ft), which is 4 m (12 ft) lower than stable level. This delta represents relatively short period of time during which level of glacial Lake Hitchcock was lowered, probably due to first effects of postglacial uplift and before lake drained due to failure of dam. Farmington River terrace deposits (ft) are fluvial deposits associated with this delta; these terraces are inset into stable-level delta surface of Bradley International Airport delta deposits (lhsb). (Windsor Locks, Hartford North)

Glacial Lake Middletown, Great Pond delta deposits - Ice-marginal deltas and fluviodeltaic deposits that record slowly lowering lake level (when adjusted for glacio-isostatic tilting) as ice margin retreated from Portland, Middletown, and Berlin northward to area near Windsor and East Windsor. See discussion of lake in accompanying text. Great Pond delta deposits - Ice-marginal delta with surface altitude of 59 to 62 m (195 to 205 ft); topset-foreset contact at about 55 m (182 ft) (projects to spillway at 21 m (68 ft)). (Windsor Locks)

Glacial Lake Middletown, Windsorville deltaic deposits - Ice-marginal deltas and fluviodeltaic deposits that record slowly lowering lake level (when adjusted for glacio-isostatic tilting) as ice margin retreated from Portland, Middletown, and Berlin northward to area near Windsor and East Windsor. See discussion of lake in accompanying text. Windsorville deltaic deposits - Ice-marginal deltaic deposits at 59 to 62 m (195 to 205 ft) built at the same time as Great Pond delta deposits (lmg) on western side of ice lobe; ice-proximal side of these deposits subjected to slight readvance of ice margin, which pushed deltaic material up into a small moraine (m). (Broad Brook)

Glacial Lake Middletown, Western margin deltaic deposits - Ice-marginal deltas and fluviodeltaic deposits that record slowly lowering lake level (when adjusted for glacio-isostatic tilting) as ice margin retreated from Portland, Middletown, and Berlin northward to area near Windsor and East Windsor. See discussion of lake in accompanying text. Western margin deltaic deposits - Ice-marginal deltas in New Britain and West Hartford with surface altitudes of 50 to 53 m (165 to 175 ft). Fluviodeltaic deposit at southern edge of New Britain has deltaic surface at 50 m (165 ft) and was built by meltwater flowing eastward through Cooks Gap. (Avon, New Britain)

Glacial Lake Middletown, Eastern margin deltaic deposits - Ice-marginal deltas and fluviodeltaic deposits that record slowly lowering lake level (when adjusted for glacio-isostatic tilting) as ice margin retreated from Portland, Middletown, and Berlin northward to area near Windsor and East Windsor. See discussion of lake in accompanying text. Eastern margin deltaic deposits - Ice-marginal fluviodeltaic deposits; fluvial deposits as high as 78 m (255 ft) just west of Rockville in Hockanum River valley grade southwestward to deltaic surfaces near Manchester at 53 to 56 m (175 to 185 ft). Distal deltaic sands and lake-bottom sediments are highly collapsed south of Manchester. (Ellington, Rockville, Manchester, Glastonbury)

Glacial Lake Middletown, Hockanum River delta deposits - Ice-marginal deltas and fluviodeltaic deposits that record slowly lowering lake level (when adjusted for glacio-isostatic tilting) as ice margin retreated from Portland, Middletown, and Berlin northward to area near Windsor and East Windsor. See discussion of lake in accompanying text. Hockanum River delta deposits - Meltwater-fed delta with surface altitude of 47 m (155 ft) and topset-foreset contact at 42 m (138 ft) (projects to spillway at 20 m (65 ft)). Constructed by meltwater spilling from glacial Lake Ellington, entrenching and reworking deposits of eastern margin deltaic deposits (lme) as meltwater entered glacial Lake Middletown at southern end of Hockanum River valley. Inset fluvial terrace deposits (ht) in Hockanum River valley are on grade to delta. (Manchester) 

Glacial Lake Middletown, Newington deltaic deposits - Ice-marginal deltas and fluviodeltaic deposits that record slowly lowering lake level (when adjusted for glacio-isostatic tilting) as ice margin retreated from Portland, Middletown, and Berlin northward to area near Windsor and East Windsor. See discussion of lake in accompanying text. Newington deltaic deposits - Highly collapsed ice-marginal delta deposits. Some noncollapsed delta surfaces remain at 50 m (165 ft) in southern part of unit and at 53 m (175 ft) in northern part. (Hartford South)

Glacial Lake Middletown, Cromwell deltaic deposits - Ice-marginal deltas and fluviodeltaic deposits that record slowly lowering lake level (when adjusted for glacio-isostatic tilting) as ice margin retreated from Portland, Middletown, and Berlin northward to area near Windsor and East Windsor. See discussion of lake in accompanying text. Cromwell deltaic deposits - Extensive ice-marginal deltaic deposits with surfaces at 44 to 47 m (145 to 155 ft) and topset-foreset contact at 41 m (135 ft) on western side of Connecticut River (projects to spillway at 33 m (107 ft)); deltas on eastern side of river, built slightly earlier, are at 50 to 56 m (165 to 185 ft) and have topset-foreset contacts at 45 m (149 ft) (projects to spillway at 37 m (120 ft)). Deltas in Cromwell have free fronts built into open water in glacial Lake Middletown basin. (Middletown, Hartford South, Glastonbury)

Glacial Lake Middletown, Portland deltaic deposits - Ice-marginal deltas and fluviodeltaic deposits that record slowly lowering lake level (when adjusted for glacio-isostatic tilting) as ice margin retreated from Portland, Middletown, and Berlin northward to area near Windsor and East Windsor. See discussion of lake in accompanying text. Portland deltaic deposits - Successive ice-marginal deltaic deposits with surface altitudes of 47 to 50 m (155 to 165 ft); topset-foreset contacts exposed in several sand and gravel pits were measured at altitudes between 43 and 46 m (140 and 150 ft) (when projected, these reflect lowering at the spillway from 40 m (130 ft) to 37 m (120 ft )). (Middle Haddam)

Glacial Lake Middletown, Lake-bottom deposits - Reddish brown, mostly varved silt and clay in couplets generally ranging from 5 to 10 cm (2 to 4 in) thick. Thickness and color of varves reflect annual deposition of beds while ice margin was in lake basin. Extensive deposits occur in basins of glacial Lakes Middletown and Berlin where section is up to 23 m (75 ft) thick.  See discussion of lake in accompanying text.

Glacial Lake Somers deposits - Successive ice-marginal deltaic and fluviodeltaic deposits built along eastern margin of Connecticut Valley ice lobe as it lay southeast of present Scantic River in Somers. Deposits are highly collapsed, especially on northwestern sides; noncollapsed parts in earlier morphosequences have deltaic surfaces at 87 to 90 m (285 to 295 ft) and fluvial surfaces that reach 111 m (365 ft). Later morphosequences have deltaic surfaces at 78 to 81 m (255 to 265 ft). Surfaces north of North Somers at 90 to 93 m (295 to 305 ft) may be from ice-hole deltas. Lake-bottom sediments occur at surface in front of 78-m (255-ft) deltas in southern part of unit. Water levels were controlled by spillway over ice-contact head of glacial Lake Ellington deposits (le). Spillway was eroded from about 87 m (285 ft) to 72 m (235 ft) during life of lake. (Hampden, Ellington) 

Glacial Lake Ellington deposits - Ice-marginal deltas with noncollapsed surfaces at 81 to 84 m (265 to 275 ft) near Sadds Mill and 84 to 87 m (275 to 285 ft) at and south of Ellington-Somers town line. Deposits grade southward to distal deltaic sand at Ellington village and lake-bottom sand and silt south of there. Spillway is not preserved but must have been over eastern margin delta deposits (lme) at about 72 m (235 ft). Meltwater discharging from this spillway cut terraces (ht) into glacial Lake Manchester (lma) and unit lme deposits farther south along Hockanum River valley, and built delta into glacial Lake Middletown (lmh). (Ellington)

Glacial Lake Uncasville deposits - Ice-marginal deltas and fluviodeltaic deposits with deltaic surfaces at 17 to 20 m (55 to 65 ft) along Thames River and Poquetanuck Cove. Fluvial deposits on grade with deltas reach 29 m (95 ft) in tributary valleys. Coarse gravel fluvial deposits in lower Oxoboxo Brook valley reach 72 m (235 ft) and have very steep surface gradient to 20-m (65-ft) delta at Uncasville. Lake was ponded behind Ledyard moraine (hlm) and Jordan Cove - lower Thames River deposits (lcjl) in Thames River valley; sediment dam has largely been removed by postglacial Thames River entrenchment. (Uncasville, Montville, Norwich)

Glacial Lake Quinebaug deposits - Successive ice-marginal deltaic and fluviodeltaic deposits and associated lake-bottom sediments. Delta-surface altitudes rise to the north from 47 m (155 ft) to 66 m (215 ft) due to glacio-isostatic tilting. Fluvial feeder deposits in tributary valleys reach as high as 87 m (285 ft). All deposits graded to single, stable lake level controlled by 41-m (134-ft) spillway over bedrock in narrow gorge where Quinebaug River turns westward, about 5 km (3 mi) south of Jewett City. Gorge probably was blocked by slightly older meltwater deposits (possibly by till); this led to establishment of drainage across adjacent 41-m (134-ft) bedrock saddle, which is about 21 m (70 ft) above present river level. Deposits of glacial Lake Quinebaug south of Quinebaug valley deposits (qb) are related to at least nine successive ice-marginal positions. Later deposits of unit lqb, north of unit qb in Blackwell Brook valley near Brooklyn, represent two successive ice-marginal deltas and associated lake-bottom deposits; altitudes of these deltas project to earlier glacial Lake Quinebaug water plane, probably due to erosion or collapse of unit qb deposits. (Jewett City, Plainfield, Danielson)

Glacial Lake Connecticut, Stamford-Norwalk-Westport deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Stamford-Norwalk-Westport deposits - Ice-marginal fluviodeltaic deposits in lower reaches of Rippowam, Noroton, Fivemile, Norwalk, and Saugatuck Rivers. Consist of fluvial sediments in the valleys of Rippowam, Noroton, and Fivemile Rivers; deltaic deposits (represented by lcd) are entirely submerged offshore from Stamford and Darien. Fluvial sediments reach altitudes of 20 m (65 ft) in Norwalk River valley and 26 m (85 ft) in Saugatuck valley and grade southward to deltaic surfaces at 5 to 8 m (15 to 25 ft) at Norwalk and Westport; bulk of these deltas, represented by lcd, are submerged below present sea level. (Stamford, Norwalk South, Sherwood Point, Westport)

Glacial Lake Connecticut, Stratford-Southport deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Stratford-Southport deposits-Fluvial deposits in Sasco Brook valley (as high as 26 m (85 ft)) grade to delta just west of Southport at 5 to 8 m (15 to 25 ft). Very coarse grained fluvial deposits in Mill River valley as high as 66 m (215 ft) grade southward to sandy delta in Fairfield at 5 to 8 m (15 to 25 ft). Fluvial deposits in Pequonnock River valley reach 26 m (85 ft) and grade to delta surface in Bridgeport at 5 to 11 m (15 to 35 ft). Ice-marginal fluvial deposits at 20 m (65 ft) in lower Housatonic River valley grade to delta in Stratford at 5 to 8 m (15 to 25 ft); these delta levels project to TRS at -14 to -15 m (-46 to -49 ft). (Westport, Bridgeport, Milford)

Glacial Lake Connecticut,  Lordship deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Lordship deposits - Ice-marginal delta with ice-contact slopes on both northeastern and northwestern sides. Surface altitude of delta is 8 to 11 m (25 to 35 ft); topset-foreset contact estimated at 5 m (15 ft) (Hokans, 1952); -12 m (-39 ft) projected to TRS. Built slightly earlier into somewhat higher lake level than Stratford-Southport deposits (lcss) and Devon-Milford deposits (lcdm) to the north. Delta is likely contemporaneous with large, submerged, ice-marginal lacustrine fan deposit that extends eastward from Lordship (lcf). Ice-margin position recorded by this delta marks interlobate angle between western Connecticut ice margin and Connecticut Valley ice lobe. Till overlying deltaic sediments on northeastern side provides some evidence of slight readvance of Connecticut Valley ice lobe from the northeast. (Bridgeport, Milford)

Glacial Lake Connecticut, Devon-Milford deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Devon-Milford deposits - Ice-marginal fluvial deposits as high as 32 m (105 ft) in Beaver Brook valley grade southward to probable delta surface at 14 m (45 ft); distal end of this deposit was eroded by later meltwater in Housatonic River valley. Fluvial deposits in Wepawaug River valley with ice-contact head at 41 m (135 ft) and in Indian River valley at 32 m (105 ft) grade to delta surface in Milford at 8 to 11 m (25 to 35 ft); -15 m (-49 ft) projected to TRS. Ice-marginal deltaic deposits near Woodmont are at 8 to 11 m (25 to 35 ft). All deposits in this unit were built from ice-margin positions on western side of northeasterly retreating Connecticut Valley ice lobe. (Milford, Ansonia)

Glacial Lake Connecticut, New Haven deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). New Haven deposits - Fluvial deposits in West River valley as high as 47 m (155 ft) and ice-marginal fluvial deposits in Mill River valley as high as 35 m (115 ft) grade southward to massive delta plain at 11 to 17 m (35 to 55 ft) in New Haven, West Haven, and Fair Haven. Topset-foreset contacts of delta, seen in excavation for Yale Bowl in West Haven and along railroad cut in Fair Haven, are at about 9 m (30 ft) and 7 m (22 ft), respectively; these levels project to TRS at -18 to -20 m (-59 to -66 ft). Deltaic sediments in New Haven overlie more than 61 m (200 ft) of lake-bottom sediment. (New Haven, Mount Carmel)

Glacial Lake Connecticut, East Haven deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). East Haven deposits - Ice-marginal fluvial deposits in Farm River valley with ice-contact head at 32 m (105 ft) grade southwest to delta at East Haven with surface at 5 to 8 m (15 to 25 ft); -20 m (-66 ft) projected to TRS. (Branford, New Haven)

Glacial Lake Connecticut,  East River-West River deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). East River-West River deposits - Ice-marginal fluvial sediments at 23 m (75 ft) in West River valley grade southward to delta at Guilford with surface altitude of 5 to 8 m (15 to 25 ft); -16 m (-52 ft) projected to TRS. Ice-marginal fluvial sediments reach 17 m (55 ft) in East River and Neck River valleys and grade southward to deltas at Madison, north of Madison moraine (mom) and head of Hammonasset River-Menunketesuck River deposits (lchm), with surface altitudes at 5 to 11 m (25 to 35 ft). (Guilford)

Glacial Lake Connecticut, Hammonasset River-Menunketesuck River deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd).Hammonasset River-Menunketesuck River deposits - Successive ice-marginal fluviodeltaic deposits. Fluvial sediments as high as 26 m (85 ft) in Menunketesuck River valley, 32 m (105 ft) in Indian River valley, and 17 m (55 ft) in Hammonasset River valley grade southward to deltas at Clinton with surface altitudes at 5 to 8 m (15 to 25 ft); -14 m (-46 ft) projected to TRS. Ice-marginal delta at Madison built along Madison moraine (mom) position has surface altitude of 5 m (15 ft); -14 m (-46 ft) projected to the spillway. Represents ice-marginal meltwater deposition graded to glacial Lake Connecticut following Hammonasset moraine (hlm) position and ending at Madison moraine (mom) position. (Clinton, Guilford, Essex)

Glacial Lake Connecticut, Westbrook-Old Saybrook-Old Lyme deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Westbrook-Old Saybrook-Old Lyme deposits - Successive ice-marginal deltaic and fluviodeltaic deposits built at mouth of Connecticut River, in its tributary valleys of Black Hall and Lieutenant Rivers, and along present shoreline in Westbrook. Consist of deltas built at three major ice-margin positions. Ice-marginal deltas with surface altitudes of 5 to 8 m (15 to 25 ft; -12 m (-39 ft) projected to TRS) were built into glacial Lake Connecticut from Old Saybrook moraine (owm) position. Ice-marginal delta north of South Cove in Old Saybrook and fluviodeltaic deposits in Black Hall River valley in Old Lyme at 5 to 8 m (15 to 25 ft) were built from second ice position. Ice-marginal deltas in Westbrook and Old Saybrook and fluviodeltaic deposits in Lieutenant River valley in Old Lyme were built from Hammonasset moraine (hlm) position. These deltas are at 5 to 11 m (15 to 35 ft) (-13 to -15 m (-43 to -49 ft) projected to TRS). (Essex, Old Lyme)

Glacial Lake Connecticut, Niantic deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Niantic deposits - Ice-marginal delta at mouth of Niantic River and ice-marginal fluviodeltaic deposits in Pataguanset River valley in East Lyme and in valleys of Threemile and Fourmile Rivers in Old Lyme were built from Old Saybrook moraine (owm) position; delta surfaces are at 8 to 11 m (25 to 35 ft), and well logs in Niantic village indicate topset-foreset contact is at about 1.2 m (4 ft) (-12 m (-39 ft) projected to TRS). In Bride Brook valley in East Lyme, coarse gravel fluvial deposits slope from 32 m (105 ft) with steep gradient to deltaic deposits at 8 to 11 m (25 to 35 ft) behind Old Saybrook moraine (owm) position; delta appears to be at glacial Lake Connecticut level, indicating that moraine did not exclude lake waters from mouth of valley. (Niantic, Old Lyme)

Glacial Lake Connecticut, Jordan Cove-Lower Thames River deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Jordan Cove-Lower Thames River deposits - Ice-marginal fluviodeltaic deposits in Jordan Brook valley and several short tributaries to Long Island Sound were built from Old Saybrook moraine (owm) position. Scattered deltaic deposits along Thames River south of Ledyard moraine (hlm) position have surfaces at 8 to 14 m (25 to 45 ft); these levels are consistent with those projected for glacial Lake Connecticut. Only remnants of these deposits remain due to extensive dissection by later meltwater as level of glacial Lake Connecticut lowered; northern extent of large Thames River drainage basin contained distal meltwater flow for much longer period of time than did its smaller adjacent valleys such as Poquonock River. (Niantic, New London, Uncasville)

Glacial Lake Connecticut, Poquonock River deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Poquonock River deposits - Ice-marginal fluviodeltaic deposits in Poquonock River valley; fluvial sediments as high as 32 m (105 ft) in upper valley and small tributaries grade southward to extensive delta with surface altitudes of 5 to 11 m (15 to 35 ft) south of Interstate Route 95 in Groton. Well logs indicate possible delta topset-foreset contact at 1 to 2 m (2 to 5 ft) altitude (-11 to -12 m (-36 to -39 ft) projected to TRS). (Uncasville, New London)

Glacial Lake Connecticut, Mystic-Stonington deposits - Glacial Lake Connecticut deposits include both onland and offshore deposits; see discussion of lake in accompanying text. Spillway for glacial Lake Connecticut at "The Race" is abbreviated below as TRS. All onland deltas have offshore extensions, which are included in offshore submerged deltaic deposit (lcd). Mystic-Stonington deposits - Ice-marginal fluviodeltaic deposits in Mystic River, Copps Brook, Stony Brook, and lower Anguilla River valleys. Ice-marginal delta in lower Mystic River valley and fluviodeltaic deposits in small valleys to the east were built in association with Mystic moraine (mm) position; deltas have surfaces at 2 to 5 m (5 to 15 ft) and are mostly submerged below present sea level. Ice-marginal fluviodeltaic deposits in Mystic River valley head at Old Saybrook-Wolf Rocks moraine (owm) position. Fluvial sediments are at 20 m (65 ft) and grade to deltaic surfaces at 2 to 8 m (5 to 25 ft) in lower valley. Topset-foreset contact appears from well logs to be at sea level; this altitude projects to TRS at -9 to -10 m (-30 to -33 ft). (Mystic, Old Mystic)

Uncorrelated deposits of ice-dammed ponds

Cobble Brook deposits - Four successive ice-marginal deltaic deposits in and adjacent to small valley on eastern side of Housatonic River. Deltas are mostly graded to 175-m (575-ft) spillway at head of valley. Low-lying deposits well below level of spillway were extensively collapsed. (Ellsworth, Kent)

Bantam River deposits - Series of ice-marginal deltas along Bantam River valley. Controlled by spillways at 239 m (785 ft) and 236 m (775 ft) at southwestern end and perhaps by some temporary higher spillways along edge of ice. Represents ice margin parallel to that of Mallory Brook deposits (ml), lower in Bantam River drainage so that numerous higher spillways of unit ml could no longer be used. (New Preston, Litchfield)

Mallory Brook deposits - Series of ice-marginal deltas along southeastern sides of Bantam River and Mallory Brook valleys. Controlled by six spillways ranging from 306 m (1,005 ft) down to 181 m (595 ft). (New Preston, Litchfield)

Woodbury deposits - Ice-marginal deltas in uplands east of Pomperaug River. Controlled by 236-m (775-ft) to 206-m (675-ft) spillways. Immediately succeeded by ice-marginal deltas perched on eastern side of river valley, controlled by 163-m (535-ft) to 102-m (335-ft) spillways. (Woodbury)

Southbury deposits - Ice-marginal deltas in northwest-sloping valley on eastern side of Pomperaug River valley. Ponding initially controlled by 142-m (465-ft) spillway across Eightmile Brook deposits (eb) to the southeast. Successive levels controlled by three side-valley spillways to the southwest at 120 m (395 ft), 108 m (355 ft), and 102 m (335 ft). (Southbury)

Still River-Saugatuck River divide deposits - Ice-marginal deltas in three valleys that slope northward from Still River-Saugatuck River drainage divide. Level of ponding in each valley controlled by spillway across divide. Successive deltas in Limekiln Brook valley were controlled by 169-m (555-ft) spillway; one delta in Wolf Pit Brook valley was controlled by 197-m (645-ft) spillway; successive deltas in Sympaug Brook valley were controlled by 126-m (415-ft) spillway that also served as glacial Lake Danbury-Saugatuck River divide stage outlet. (Danbury, Bethel, Newtown, Botsford)

Pootatuck River-Pequonnock River divide deposits - Ice-marginal deltas in several valleys (including Pootatuck River) that slope northward from divide. Levels of ponding in Hurds Brook valley controlled by successively lower spillways at 157 m (515 ft), 154 m (505 ft), 136 m (445 ft), and 126 m (415 ft). Levels of ponding in two small tributary valleys to Halfway River controlled by two spillways at 126 m (415 ft) and 117 m (385 ft). Small pockets in upper reaches of Pootatuck River basin controlled by local spillways across divide at 157 m (515 ft) to 130 m (425 ft). (Newtown, Botsford, Long Hill)

Tolles-Terryville deposits - Ice-marginal deltas ponded in small upland valleys on eastern side of Naugatuck River. Deposits near Tolles were controlled by spillways at 276 m (905 ft) and 242 to 206 m (795 to 675 ft) between Naugatuck River tributaries. Deposits near Terryville are in Poland River basin and controlled by a spillway at 203 m (665 ft) into Naugatuck River tributary. Ponding in these valleys controlled by ice positions at or near interlobate angle between western side of Connecticut Valley ice lobe and western upland ice margin. (Thomaston)

East Mountain Reservoir deposits - Ice-marginal deltas ponded in west-sloping tributaries of Naugatuck River. Controlled by multiple spillways across valley divides at altitudes ranging from 221 m (725 ft) to 126 m (415 ft). Sequential ponding in these valleys controlled at interlobate angle between western side of Connecticut Valley ice lobe and western upland ice margin. (Waterbury, Naugatuck)

Bethany deposits - Ice-marginal deltas ponded at multiple stages in four west-sloping tributaries of Naugatuck River. Spillways cross local divides between tributaries between 59 m (195 ft) and 194 m (635 ft). Sequential ponding in these valleys required ice-margin positions with strong north-northeast to south-southwest trend. (Naugatuck)

West Branch Salmon Brook deposits - Ice-marginal deltas ponded at several levels in headwaters and tributaries of eastward-flowing West Branch Salmon Brook by western margin of Connecticut Valley ice lobe. Highest group of deposits is graded to spillways above 305 m (1,000 ft). A slightly younger group of deposits has spillways between 270 and 198 m (885 and 650 ft). Lowest group was impounded behind Barndoor Hills and graded to spillways at 126 m (415 ft), 117 m (385 ft), and 102 m (335 ft). (Tariffville, New Hartford)

Onion Mountain deposits - Ice-marginal deltas in small north-sloping pockets east and north of Onion Mountain. Deposits are highly collapsed; only narrow fringes of noncollapsed deltaic surfaces are present. Deposits were ponded against scarp of Western Highlands by Connecticut Valley ice lobe and graded to three local spillways at 209 m (685 ft), 181 m (595 ft), and 160 m (525 ft). (Avon, Tariffville, Collinsville)

Burlington deposits - Ice-marginal deltas ponded high against edge of Western Highlands by Connecticut Valley ice lobe. Delta surfaces are successively lower to northeast and were controlled by succession of lower spillways between 288 m (945 ft) and 181 m (595 ft) across Burlington Brook-Pequabuck River drainage divide. (Collinsville)

Whigville deposits - Ice-marginal deltas ponded against collapsed slope of higher level glacial Lake Bristol deposits (lbr). Graded to two spillways at 120 m (395 ft) and 127 m (415 ft). As ice margin retreated, the lake at Whigville at 127 m (415 ft) drained; meltwater that continued to spill from Burlington lakes eroded parts of Whigville deltas. (Bristol)

Quinnipiac River-Mill River divide deposits - Ice-marginal deltas ponded in four north-draining valleys tributary to Quinnipiac River. In Tenmile River valley, deltaic surfaces are at 63 to 66 m (215 to 225 ft) and are graded to 59-m (195-ft) spillway across divide. In valley of unnamed tributary to Tenmile River, deltaic surfaces reach 62 m (205 ft) and were controlled by 56-m (185-ft) spillway. In Honeypot Brook valley, esker-fed delta has surface altitude of 63 to 69 m (205 to 215 ft) graded to 59-m (195-ft) spillway. In Broad Brook valley, there are two successive deposits; older delta has extensive collapsed ice-marginal parts south of Broad Brook Reservoir, but small noncollapsed delta surfaces at 78 m (255 ft) remain; ponding controlled by a 75-m (245-ft) spillway; younger delta north of reservoir has surface at 72 m (235 ft), controlled by 66-m (215-ft) spillway. Extensive collapsed ice-marginal parts of this deltaic sequence, including a 2-km-long (1.5-mi-long) feeder esker, block northern end of Quinnipiac Gorge and probably contributed to damming of glacial Lake Southington. (Southington, Meriden, Mount Carmel, Wallingford)

Mount Sanford ridge deposits - Ice-marginal deltas in high-level pockets in several northeast-sloping valleys that drain ridge extending north and south from Mount Sanford. Level of deposits was controlled in each valley by lowering succession of spillways that resulted from northeastward retreat of western margin of Connecticut Valley ice lobe. Spillway altitudes range from 197 m (645 ft) down to 50 m (165 ft). (Mount Carmel)

Somers high-level deposits - Ice-marginal deltas in several pockets graded to local spillways that  lower successively to the west from 247 m (810 ft) down to 148 m (485 ft). Ice-marginal deltaic deposits in Monson, Mass., were graded to lacustrine deposits in this series with spillway at 215 m (705 ft) east of Perkins Mountain. (Hampden)

Shenipsit Lake deposits - Ice-marginal delta at 168 m (550 ft) overlying as much as 21 m (70 ft) of lake-bottom sand and silt just south of Shenipsit Lake. Deposit was ponded by ice margin to the west and north and controlled by a spillway over older upper Connecticut River divide deposits (cd) that probably contained buried ice. North of Shenipsit Lake, deposits reach 209 m (685 ft), but have no recognizable spillway and are mostly collapsed from former levels. Deposits south of Crystal Lake straddle the eastern upper Connecticut drainage divide and were deposited from ice-margin positions east of divide by meltwater flowing southwest through local spillways. (Rockville, Ellington)

Wapping deposits - Ice-marginal deltas ponded in two pocket valleys against eastern upland before opening of glacial Lakes Middletown and Hitchcock in this area. Higher deposit was graded to two spillways at 84 m (275 ft) and 81 m (265 ft). Lower deposit has a terrace form and was ponded along ice margin and controlled by 56-m (185-ft) spillway between bedrock hills to the east. (Manchester)

Vernon-Lydallville deposits - Successive ice-marginal deltas ponded against Eastern Highlands; slightly younger and lower in altitude than northern part of upper Connecticut River divide deposits (cd). Most of these deposits are highly collapsed but some delta surfaces remain, graded to lowering successive ponding controlled by spillways from 172 m (565 ft) down to 105 m (345 ft). (Rockville)

Upper Connecticut River divide deposits - Ice-marginal deltaic deposits built into four upland lakes, impounded by eastern margin of Connecticut Valley ice lobe; lakes spilled through saddles at 154 m (505 ft), 197 to 200 m (645 to 655 ft), 187 m (615 ft), and 239 m (785 ft) across eastern part of upper Connecticut River drainage divide. Southernmost lake in this unit was previously named glacial Lake Dickinson (Langer, 1977). (Glastonbury, Rockville)

Hanging Hills deposits - Series of ice-marginal deltas in three valleys that drain northeastern slope of Hanging Hills. In Mattabesset River valley and its headwater tributaries, spillway altitudes lower northward from 114 m (375 ft) down to 53 m (175 ft). In Hatchery Brook valley, spillway altitudes range from 96 to 56 m (315 to 185 ft). In both valleys, deltaic surfaces are lower to the north, each graded to a lower spillway. In the Belcher Brook valley, deltaic surfaces are at 56 to 59 m (185 to 195 ft) and are graded to 50-m (165-ft) spillway south of Beaver Pond. (Meriden)

Coginchaug River divide deposits - Ice-marginal deltas ponded in four pocket valleys against Coginchaug River divide soon after ice margin retreated northward across it. Each delta was controlled by a spillway across the divide. Further retreat into the basin resulted in development of glacial Lake Coginchaug, represented by Durham stage deposits (lcgd) and Middletown stage deposits (lcgm), which spilled across divide at lower altitude. (Durham)

West Haddam deposits - Series of ice-marginal deltas ponded in small northeast-draining tributaries to Connecticut River. Spillways range from 172 m (565 ft) down to 102 m (335 ft) across local divides. Deposition of these small, high-level deltas in successively lower positions to the northeast was due to lobation of ice margin in lower Connecticut River valley; western side of this lobe retreated to the northeast. (Haddam)

Moodus River divide-Pine Brook deposits - Small ice-marginal deltas in northwest-sloping tributary valleys to Moodus River. Oldest deltas in each valley were graded to spillways at 108 m (355 ft), 114 m (375 ft), and 142 m (465 ft) across the southern Moodus River divide. Successive lower deltas in each valley were graded to lower spillways across smaller valley divides. Relatively extensive ice-marginal deltas in Moodus Reservoir valley and at southern end of Pine Brook valley have surface altitudes at 123 to 126 m (405 to 415 ft) and were built into small, open lake that spilled eastward over 120-m (395-ft) spillway across Moodus River divide. Unlike most deltas in this type of depositional system, these have free fronts, and lake-bottom surfaces may underlie areas now flooded by Moodus Reservoir. Deposits in north-draining Pine Brook valley, north of Babcock Pond, are series of three ice-marginal deltas graded to 117-m (385-ft) spillway that cuts through 128-m (420-ft) ice-marginal head of delta south of Babcock Pond. This lower ponding could not occur until ice margin retreated out of Moodus River valley and lake in Moodus Reservoir valley drained westward down Moodus River valley. (Moodus, Deep River)

Judd Brook-Gillette Brook deposits - Three ice-marginal deltas built in lowering succession in Judd Brook valley graded to spillways at 155 m (510 ft), 139 m (455 ft), and 126 m (415 ft). Three successive ice-marginal deltas in Gillette Brook valley east of glacial Lake Colchester graded to spillways at 160 m (525 ft), 157 m (515 ft), and 130 m (425 ft). (Colchester)

Colchester deposits - Two successive ice-marginal deltaic deposits that cross present drainage divides between upper Deep River and Lake Hayward Brook. Relationship between deposits and topography indicates that former divides were at narrows at south ends of the two deposits; divides were shifted northward after deltas were built. (Colchester)

Beaver Brook deposits - Successive ice-marginal deltaic deposits with surfaces at 29 to 47 m (95 to 155 ft) that cross present divide between Beaver Brook and Falls Brook. Initial spillway must have been across rock ridge south of Uncas Pond, but present altitude of lowest col is too low to have controlled deposits; detached ice blocks must have been present in area. Upper Cedar Pond Brook valley at northeastern end of deposit was ice free and contains fluvial feeder deposits up to 69 m (225 ft) on grade to deltaic surfaces south of Cedar Lake. (Hamburg, Old Lyme)

Mashapaug Pond deposits - Ice-marginal deltas built into series of small lakes ponded against upper Quinebaug River-Shetucket River drainage divide at five successively lower spillways across divide at altitudes of 294 m (965 ft), 276 m (905 ft), 267 m (875 ft), 255 m (835 ft), and 215 m (705 ft). Deposits are particularly rusty because of abundance of sulfitic schist fragments. (Wales, Westford)

Conant Brook-Roaring Brook deposits - Ice-marginal deltas built into two groups of small lakes on eastern side of Willimantic River. Deposits in Conant Brook valley were controlled by successively lower local spillways at 219 m (720 ft), 203 m (665 ft), and 175 m (575 ft). Deposits in Roaring Brook valley were controlled by spillways across divide between two valleys at 655 ft (200 m), 635 ft (194 m), 615 ft (187 m), and 535 ft (163 m). (Stafford Springs, South Coventry)

Cedar Swamp area deposits - Successive ice-marginal deltaic deposits in Cedar Swamp valley and in north-draining tributaries to Eagleville Brook valley, Conant Brook valley, and small tributary valleys on eastern side of Willimantic River. Earliest deposits in Cedar Swamp valley contain extensive ice-channel fillings and were controlled by 169-m (555-ft) spillway; these deposits blocked the valley. Successive deposits north of Cedar Swamp were controlled by 178-m (585-ft) spillway. (South Coventry)

Fitchville deposits - Ice-marginal deltas in seven north-draining tributaries to Yantic River; single deltas in each valley were controlled by spillways across each local divide. (Fitchville, Norwich)

Gardner Lake lacustrine deposits - Successive ice-marginal deltaic deposits in north-draining Deep River valley and in Gardner Brook valley where deposits bury former divide. Deltaic deposits north of Gardner Lake have surface altitudes of 123 to 126 m (405 to 415 ft) and were built into small lake controlled by 120-m (395-ft) spillway. Deltas in Deep River valley, including one near-ice-marginal delta, have surface altitudes of 130 m (425 ft) and were built into small lake controlled by 127-m (415-ft) spillway across divide at The Wales. Slightly lower deltas on northern side of Deep River Reservoir are extensively collapsed and were controlled by 117-m (385-ft) spillway across deposits occupying divide area north of Gardner Lake. (Fitchville, Colchester)

Ledyard deposits - Ice-marginal deltas in three north-draining tributaries to Thames River. Deltas with surfaces at 50 to 60 m (165 to 185 ft) in Billings Avery Brook valley contain numerous well-developed kettles and were controlled by two spillways that cross Ledyard moraine (hlm) and head of Groton deposits (gr) at 53 m (175 ft) and 47 m (155 ft). Deltas in Joe Clark Brook and Shewville Brook valleys to the north were controlled by three local spillways at 53 m (175 ft), 47 m (155 ft), and 38 m (125 ft). (Uncasville)

North Thompson deposits - Ice-marginal deltas with esker feeder deposits in two north-sloping tributary valleys. Eastern valley is tributary to Fivemile River valley and has delta surfaces at 157 m (515 ft), controlled by 151-m (495-ft) spillway across divide; western valley is tributary to French River valley and has two successive deltas at 154 m (505 ft) and 151 m (495 ft), controlled by 145-m (475-ft) spillway. (Webster, Oxford)

East Putnam-Glocester deposits - Successive ice-marginal deltas in northwest-sloping Cady Brook and Mary Brown Brook valleys. Series of ponds began in Glocester, R.I., controlled by two spillways across Quinebaug River divide; first spillway is in Rhode Island, second spillway at 178 m (585 ft) is in Connecticut. Later spillways for ponding in Connecticut descend from 142 m (465 ft) to 130 m (425 ft). (Thompson)

White Brook deposits - Four successive ice-marginal deltas in White Brook valley; deposits are extensively collapsed. Series of ponds controlled by spillways at 93 m (305 ft), 90 m (295 ft), and 84 m (275 ft) across local divide. (Danielson)

Mashentuck Brook deposits - Ice-marginal deltas in north-draining Mashentuck Brook valley. Ponding controlled by two spillways at 130 m (425 ft) and 123 m (405 ft). (East Killingly)

Wauregan deposits - Three successive ice-marginal deltaic and deltaic-fluvial deposits in north-sloping tributary valley to Quinebaug River. Ponding was controlled by two 69-m (225-ft) spillways across southern divide. Highly collapsed deposits that reach 87 m (285 ft) in northern part of unit are chiefly fluvial. (Danielson, Plainfield) 

Mill Brook deposits - Four successive ice-marginal deltas in north-draining Mill Brook valley. Sediment was deposited around numerous stagnant ice blocks. Levels of ponding were controlled by spillways at 53 m (175 ft) and 50 m (165 ft) across divide at southern end of unit. (Plainfield, Jewett City)

Broad Brook deposits - Two successive ice-marginal deltas in lower part of north-draining Broad Brook valley. Level of ponding was controlled by 50-m (165-ft) spillway across local divide. (Jewett City)

Bay Mountain deposits - Successive ice-marginal deltas related to nine ice-margin positions in three relatively steep, north-sloping valleys in Bay Mountain upland area. Eastern valley occupied by Billings Brook contains most extensive deposits and is tributary to Pachaug River basin. Earliest and highest levels of ponding in this system controlled by spillway at 99 m (325 ft) across Quinebaug River basin divide; some later levels controlled by spillways across local divides, but downstream from these, path of meltwater flow was across basin divide through 69-m (225-ft) spillway. (Jewett City, Old Mystic)

Uncorrelated deposits of sediment-dammed ponds

Salisbury deposits - Ice-marginal fluvial deposits reach as high as 230 m (755 ft) in northern part of unit; grade southward to ponded sediments in Salisbury village area. Near-ice-marginal fluviodeltaic deposits built from the west overlie lake-bottom deposits at Lakeville. Ponding probably was in overdeepened bedrock basin behind Salmon Creek narrows at southern end of unit. (Bashbish Falls, Sharon)

Housatonic River deposits from New Milford to West Cornwall - Sequential ice-marginal deltaic and fluviodeltaic deposits along Housatonic River between New Milford village and West Cornwall; fluvial feeder deposits in some steeper tributary valleys to Housatonic River. Numerous ice-margin positions identified, although deposits in many places are only discontinuous remnants due to extensive distal-meltwater and postglacial erosion. Deltaic surfaces are at 81 m (265 ft) at southern end of unit and 184 m (605 ft) at northern end; shingled-profile breaks identified in many places in association with ice-margin positions. Ponding in this part of valley began immediately following drainage of last stage of glacial Lake Danbury; initial impoundment was behind glacial Lake Danbury deposits. (New Milford, Kent, Dover Plains, Ellsworth, Cornwall, South Canaan)

Housatonic River deposits from Stratford to Shepaug River - Discontinuous remnants of sequential ice-marginal deltaic deposits along Housatonic River between Stratford and mouth of Shepaug River in Southbury. Surface altitudes at 17 m (55 ft) at southern end of unit rise with minor identifiable shingled-profile breaks to 78 m (255 ft) at northern end of unit. Deposits were considerably incised by later meltwater and postglacial erosion so that reconstruction of surface gradients, ice-margin positions, and delta surfaces is precluded. Initial ponding in valley began directly following deposition of Stratford-Southport deposits (lcss) into glacial Lake Connecticut at mouth of valley. (Milford, Ansonia, Long Hill, Southbury, Newtown)

Shepaug River deposits - Largely discontinuous remnants of sequential ice-marginal deltaic deposits along lower Shepaug River. Probably related to at least three ice-marginal positions with levels of ponding between 72 m (235 ft) and 84 m (275 ft). Initial ponding behind last deposits of Housatonic River (hrs) in Housatonic River valley. (Roxbury, Newtown)

Eightmile Brook deposits - Several ice-marginal deltaic and fluviodeltaic deposits in Eightmile Brook and Little River valleys; northern sequences have extensive fluvial sections. Initial ponding in southern part of unit was behind till and (or) bedrock spillway on side of valley; successive sequences controlled by sediment-dammed ponding. Meltwater deposits also spilled southeast into upper part of Little River valley. (Southbury)

Pequonnock River-Farmill River deposits - Ice-marginal and near-ice-marginal fluviodeltaic and deltaic-fluvial deposits in upper reaches of Mill, Pequonnock, and Farmill River valleys and their tributaries. Ponding in many places was in overdeepened basins behind bedrock narrows; in other places, such as at Stepney in Pequonnock River valley, sequential ponding was behind successive ice-contact heads in valley. Meltwater construction of this system in upper reaches of these valleys closely followed construction of fluviodeltaic Stratford-Southport deposits (lcss) that graded to glacial Lake Connecticut in lower reaches of valleys. (Botsford, Long Hill, Bridgeport)

Saugatuck River-Aspetuck River deposits -  Near-ice-marginal fluviodeltaic and deltaic-fluvial deposits in upper Saugatuck River valley and tributary Aspetuck River valley. Initial ponding was behind head of Stamford-Norwalk-Westport deposits (lcsnw) at Westport; subsequent ponding was mostly in wider basins behind bedrock narrows with only minor sediment damming. Deposits in West Branch Saugatuck River valley included in this unit are largely fluvial, but southern part may have been tributary feeder to deltaic deposits at Saugatuck River valley confluence. (Botsford, Norwalk North, Westport, Norwalk South, Sherwood Point)

Upper Norwalk River deposits - Sequential near-ice-marginal fluviodeltaic deposits in upper Norwalk River and Silvermine River valleys. Fluvial deposits in narrower and steeper sections of valleys grade to deltaic deposits ponded in overdeepened basins behind bedrock narrows; successive northward construction of this depositional system indicated by distribution of textures within deposits rather than shingled-surface profiles. (Bethel, Norwalk North) 

Rippowam River-Noroton River deposits - Sequential near-ice-marginal fluviodeltaic deposits in Rippowam and Noroton River valleys. Fluvial deposits in narrower and steeper sections of valleys grade to deltaic and lacustrine deposits in deeper basins near Interstate Route 95. Successive northward construction within this unit indicated by textural distribution rather than shingled-surface profiles. (Pound Ridge, Stamford)

Naugatuck River deposits from Thomaston to Litchfield - Near-ice-marginal fluviodeltaic deposits in southern half of unit. Ponded initially behind head of Naugatuck River deposits from Naugatuck to Reynolds Bridge (nrn) at about 122 m (400 ft). Ice-marginal fluvial deposits of very coarse gravel at northern end of unit reach 152 m (500 ft) and grade southward to deltaic deposits at 133 m (435 ft) just north of Thomaston Dam. (Thomaston)

Naugatuck River deposits from Naugatuck to Reynolds Bridge - Sequential ice-marginal deltaic and fluviodeltaic deposits and near-ice-marginal fluviodeltaic deposits in Naugatuck River from Naugatuck northward to Reynolds Bridge. Earliest deposits in this unit are fluviodeltaic deposits built in two tributary valleys to Naugatuck River (Beacon Hill Brook from east and Long Meadow Pond Brook from west). Early levels of ponding at 96 m (315 ft) must have been controlled by drift and (or) ice in narrow bedrock gorge of Naugatuck River south of unit. Inset against higher ponded deposits in main valley at Naugatuck are deltaic deposits at 81 m (265 ft). Delta surfaces rise northward through this section of valley to 120 m (395 ft), a gradient of about 1.5 m/km (8 ft/mi) (0.8 m/km (4 ft/mi) when postglacial tilt is taken into account). (Thomaston, Waterbury, Naugatuck)

Mad River deposits - Ice-marginal and near-ice-marginal fluviodeltaic deposits in Mad River valley built from ice both in upper Mad River and along Naugatuck River. Initial spillway at 136 m (445 ft) across East Mountain Reservoir deposits (emt) in Hopeville Brook valley. Later spillway across earlier head at Mill Plain controlled ponding levels in northern part of unit at about 137 m (450 ft). (Waterbury, Southington)

Naugatuck River deposits from Derby to Beacon Falls - Ice-marginal and near-ice-marginal fluviodeltaic deposits in Naugatuck River valley from confluence with Housatonic River northward to Beacon Falls. Fluvial feeder deposits reach 72 m (235 ft) in short tributary valleys and grade to deltaic deposits in main valley. Levels of ponding recorded in deltas are about 30 m (100 ft) at southern end of unit and about 61 m (200 ft) at Beacon Falls, a rise of approximately 1.9 km/km (10 ft/mi) (1.2 m/km (6 ft/mi) when postglacial tilt is taken into account). (Naugatuck, Ansonia)

Barkhamsted Reservoir deposits - Highly collapsed deposits south of Saville Dam. Maximum altitudes reach 149 m (490 ft) and probably are deltaic, ponded behind 152-m (500-ft) upper Farmington River deposits (fu) south of Puddle Town. North of Saville Dam, only scattered probable deltaic surfaces are visible above reservoir water level; altitudes are at 172 m (565 ft) and reach 178 m (585 ft) at ice-margin position just north of Barkhamsted town line. North of this position, deposits with surfaces at 166 m (545 ft) rise northward to 181 m (595 ft). North of reservoir, presumably fluvial deposits with 198-m (650-ft) surfaces continue on steep gradient into Massachusetts. (New Hartford)

Southwick-Suffield deposits - Successive ice-marginal deltaic deposits with delta surfaces at 78 to 81 m (255 to 265 ft); initial spillways were over heads of deposits of glacial Lake Tariffville (lt). Deposits continue northward into Massachusetts where massive ice-marginal deltas surrounding Congamond Lakes have surfaces that reach 84 m (275 ft). (Tariffville, Southwick, West Springfield)