Summary for Field Activity Number 1970-007-FA

Alternate Leg ID: GOSNOLD 164

Area of Operations: western Gulf of Maine, Jeffreys Ledge, Jeffreys Basin, Casco Bay, Massachusetts Bay, Cape Cod Bay, Stellwagen Bank, Massachusetts, New Hampshire, Maine, United States, North America, North Atlantic

Dates: June 10, 1970 to June 16, 1970

Objectives: The main purpose was to complete bottom sediment sampling in the nothern quadrangle and to do additional 3.5 kHz seismic profiling as a supplement to those taken in earlier cruises of the GOSNOLD and VERRILL last year.

Type of Activity: Sampling
Seismic profiling

Information to be derived: Grain size analysis

Summary: A total of 154 stations were occupied during the seven days at sea. The GOSNOLD steamed a total of 691 miles during which we obtained approximately 600 miles of sonic profiles. Samples were taken 2-4 miles apart and were selected utilizing a 1/40,000 scale bathymetric map of the sea floor compiled by the Coast & Geodetic Survey. Selection was key to a variety of topographic features in the area, some only a few hundred meters across. Despite very complex topography, the type of sediment was restricted to relatively few types - broadly outlining topographic provinces rather than particular features. Sonic profiles showed penetration 20 fms over soft bottom and a multilayered arrangement of reflecting horizons over basins. Some of the reflectors appear to pinch out toward the basin edge or to have an erosional pinch out at the edge.

USGS Project Number:

Contact: John Schlee (jschlee@usgs.gov)