Geologic features of the sea bottom around a municipal sludge dumpsite near 39 degrees N., 73 degrees W., offshore New Jersey and New York

The sea-floor of a dumpsite area offshore New York and New Jersey (Deep-water dumpsite 106) was studied using detailed bathymetry, sidescan-sonar images, subbottom profiles, bottom photographs, and bottom-sediment samples. These data show that this continental rise area contains deposits of submarine landslides and pathways of sediment gravity flows. Images of the sea floor obtained with a deep-towed high-resolution sidescan sonar system show offshore-trending furrowed surfaces over parts of the area. If such furrows are old, one might expect them to have been obliterated by sediment resuspension and redeposition due to the mostly gentle contour-parallel bottom currents that are measured in the present day. While most of the sea-floor features were probably formed during Pleistocene or early Holocene (glacial or early post-glacial) times, our information suggests that vigorous present-day episodes of offshore-directed transport may continue to occur, at unknown intervals.