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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: LISAT-13

SHIP: R/V Atlantic Twin
LOCATION: Connecticut.iver, eastern Long Island Sound
LATITUDE: 41o 12.65' N
LONGITUDE: 72o 18.7' W
LORAN: 26251.4, 43970.2
COMMENTS: Seismic line for this core is Line AT#11 (sparker). This lines runs from 1253-1303. hrs. Core at 1257 on record. Core into older Connecticut.iver deposits. Target site was I-4 on uniboom record line 7, at 1646, AST 82-3, at 1649 on 2/85). During this core the joint in the core liner (at 20' up from the bottom) let go and some of the core (about 1') got out. The bottom 20' of core seems OK. Some of the sand from the break area was collected in a large bag. The top 4' of the core was capped and saved also. This should still be a good core. Section 4 contains 9-cm void at top. Not cut.
PENTROMETER RECORD: Rapid 0-13'; moderate 14-17'; slow 18', moderate 19' to end
0-125 cm (Section 1) - 0-14.5cm: dark grayish brown, 10YR 4/2, sand, mediun, silty, some pebbles above 6 cm, medium sand grades to coarse sand between 6-14.5 cm, some shell fragments. 14.5-80 cm: dark olive gray, 5Y 3/2, mottled silt and fine sand, medium to coarse sand between 40-52 cm, cohesive, some shell fragments, gradational contact into poorly section below. 80-125 cm: poorly sorted silt, sand, gravel (rock fragments of granite, quartz monzonite, red sandstone,..etc), and occasional shell fragments, bebbles concentrated at base of section, shapp contact at base of section.
125-248 cm (Section 2) - 125-192 cm: grayish brown, 10YR 5/2, sand, fine to medium, minor silt, sharp contact with lower unit, silty bleb at 138 cm, (160-167 cm: 99% sand, 1% silt, 0% clay). 192-248 cm: grayish brown, 10YR 5/2, sand, medium to coarse, gravel (smoothed rock fragments), poorly sorted, pebbles concentrated between 222-244.
248-401 cm (Section 3) - 248-344.5 cm: sand, coarse, with smooth gravel (rock fragments), poorly sorted, fine - medium sand between 269-274.5, sharp lower contact (278-280 cm: 20% gravel, 80% sand). 344.5-369 cm: transition zone, mottled section of fine sand and clayey zones, grading into underlying clay layers. 369-401 cm: Varves, alternating layers of brown, 7.5YR 4/2, clay and dark brown, 7.5YR 3/2, silty clay; clay layers average 2.0 cm thick; silty clay layers average 1.5 cm thick.
401-554 cm (Section 4) - Brown, 7.5YR 5/2, and dark brown, 7.5YR 3/4 varved lake clays, 3.5-5.0cm wavelength, thicker clay layers, thinner silty clay layers, convex upward, (512-519 cm: 1% sand, 89% silt, 10% clay).
554-711 cm (Section 5) - Varved lake clays, variation in varve thickness 2.5-5.0 cm, except between 620-628 where varve separation is about 1.0 cm, silty fine sand layer at 644-651 cm, no layering (disturbed?) below 704 cm.

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