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U.S. Geological Survey Open-File Report 02-002

Geological Framework Data from Long Island Sound, 1981-1990:

A Digital Data Release

Visual Core Description: AT88-8

SHIP: R/V Atlantic Twin
CRUISE: AT-88
CORE: AT88-8
LENGTH: 763 cm
DATE OF CORE: 9/88
DESCRIBED BY: N. Neff
LOCATION: South of New London Harbor, Long. Island Sound
LATITUDE: 41o 16.1' N
LONGITUDE: 72o 05.6' W
LORAN: 26144.9, 43977.2
WATER DEPTH (m): 23
DATE SPLIT: 3/89
0 - 171 cm - Dark gray, 5Y 4/1, firm silt with lesser amounts of clay and sand: whole shells and shell fragments from 0 - 78 cm. Flow - in structure from 70 - 155 ( - ) cm; color of flow - in sediment ranges from olive to strong brown. 155 - 171 cm: Olive 5Y 5/3 silt and fine sand. (Note: may be contact between upper gray, shelly unit and lower, slightly coarser olive unit but it has been obscured by the flow - in structure). Sharp, horizontal lower contact.
171 - 216 cm - This unit consists of two parts of two different cut sections. 171 - 203 cm comprises the bottom of section 2; 205 - 216 cm comprises the top of section 3. There is an apparent color difference between these two parts but it is believed to be the result of differences in water contact. Fine sand. 171 - 203 cm: gray, 5Y5/1. 205 - 216 cm: light brownish gray, 2.5Y 6/2.
175 - 185 cm folded and contorted laminae ranging in color from very dark gray to reddish brown; individual layers less than I cm thick. Sharp, horizontal lower contact.
216 - 267 cm Olive brown, 2.5Y 4/4, and olive 5Y 4/3, firm, very fine sand and silt occurring in lightly contorted layers of different colors. 217 cm: very thin laminae of red clay. 237 cm: red clag layer 0.5 cm thick, diagonal. Gradational, inclined lower contact.
267 - 307 cm -  Dark, yellowish - brown, 10Y 4/6, hard, fine to medium sand. Sharp, slightly inclined lower contact.
307 - 433 cm -  Light olive gray, 5Y 6/2, and light olive brown, 2.5Y 5/6, firm, very fine to medium sand occurring in highly folded and contorted layers of different color. 330 cm: flecks of black mineral. 383 cm: small inclusion of red clay. 415 - 421 cm: very thin, horizontal laminations of very fine sand and silt. 421 - 433 cm: flecks of black mineral. Sharp, horizontal lower contact.
433 - 763 cm - Gray, 5Y 5/1, and light gray, 5Y 7/1, firm, fine sand occurring m sub - horizontal to highly contorted layers. 433 - 450 cm: fine sand stained brown - red. 445 - 480 cm and 639 - 672 cm: massive gray sand, no structures. Laminae at 510 cm, 510 - 550 cm, 622 - 633 cm, 680 - 710 cm, 730 - 740 cm, 760 cm. Red clay inclusions less than I cm thick at 533 cm (inclined), 560 cm (horizontal), 614 cm (inclined), 632 cm (disturbed), 683 cm (horizontal), 706 cm (disturbed), 740 cm (disturbed), 758 cm (disturbed).


Department of the Interior > U.S. Geological Survey > Coastal and Marine Geology Program  > Long Island Sound Studies
Contact: L.J. Poppe (lpoppe@usgs.gov")