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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-6
| SHIP: | R/V Atlantic Twin |
| CRUISE: | AT-84 |
| CORE: | LISAT-6 |
| LENGTH RECOVERED: | 783 cm |
| PENETRATION: | 29' |
| NUMBER OF SECTIONS: | 5 |
| LOCATION: | Stratford Shoal, western Long Island Sound |
| LATITUDE: | 41o 05.03' N |
| LONGITUDE: | 73o 06.33' W |
| LORAN: | 26650.5, 43987.1 |
| COMMENTS: | Seismic line for this core is Line AT#5 (sparker). This lines runs from 0948-0958 hrs. Core at 0955 hrs. on record. Core into lake clay (site III-1 on uniboom record line 17, UCONN 84-1). Section 1 - near the bottom is the lake clay contact - contains a concretion. |
| PENTROMETER RECORD: | Rapid 0-20'; moderate 20'-end |
| 0-148 cm (Section 1) - | 0-140 cm: very dark gray, 5Y 3/1. 0-48 cm: large quartz pebbles prevalent, with shell hash in silty clay and sand. 48-145 cm: no pebbles, abundant shell hash in silty clay and fine sand, very porous (air around shell fragments). 140-148 cm: lake clay varves, dark layers are brown - dark brown 7.5YR 4/2; light layers are brown, 7.5YR 5/4, clay or silty clay, no apparent difference in grain size, lighter layers are smoother; darker zones are denser. Clay concretion near bottom of section. |
| 148-295 cm (Section 2) - | Clay, lake clay varves, dark layers are brown - dark brown 7.5YR 4/2; light layers are brown, 7.5YR 5/4, varves are mostly 1.5-2 cm in wavelength, light layers are always thinner (0.5-0.7 cm) than the dark layers (1.0-1.2). |
| 295-448 cm (Section 3) - | Clay, lake clay varves, dark layers are brown - dark brown 7.5YR 4/2; light layers are brown, 7.5YR 5/4, varves are mostly 1.5-2 cm in wavelength, light layers are always thinner (0.5-0.7 cm) than the dark layers (1.0-1.2). Varves are more disturbed than in overling section (2-3 cm convex upward). |
| 448-601 cm (Section 4) - | Clay, lake clay varves, dark layers are brown - dark brown 7.5YR 4/2; light layers are brown, 7.5YR 5/4, varves are mostly 2-3 cm in wavelength, light layers are usually thinner than the dark layers, 58 couplets in section, very convex upward. Dark layers 5 and 6 cm partly due to distortion in the intervals 505-511 cm and 513-517 cm, respectively. |
| 601-692 cm (Section 5A) - | Clay, lake clay varves, dark layers are brown - dark brown 7.5YR 4/2; light layers are brown, 7.5YR 5/4, varves are mostly 2-3 cm in wavelength, greater wavelengths at 652, 656, and 663 cm. |
| 692-783 cm (Section 5B) - | Clay, lake clay varves, dark layers are brown - dark brown 7.5YR 4/2; light layers are brown, 7.5YR 5/4, varves are mostly 1-2 cm in wavelength, thicker dark layers at 704.5-710.5, 756-759.5, and 773-777 cm. |