Comparison of Clay from the Continental Shelf off Long Island with the Gardiners Clay

Abstract

Late in 1955 the Woods Hole Oceanographic Institution received from Moran, Proctor, Mueser, and Rutledge, consulting engineers of New York City, a few samples taken from a boring made at the proposed site of an Air Force Texas Tower (TT-4), located about 60 miles south of Moriches Bay, Long Island. Among these samples was an undisturbed clay sample, suggestive of the Pleistocene Gardiners clay of Long Island. For purposes of comparison, the same company later made available a group of ten core samples collected from a formation thought to be Gardiners clay on western Long Island. Standard mechanical analysis procedures were carried out on certain of these samples prior to their being examined for microfossils. The sample from the TT-4 site was located 70 feet below the ocean bottom under a water depth of 185 feet. The overlying sediments were coarse sand and fine gravel. The moist color of this sample was olive-gray as determined from the Rock Color Chart published by the Geological Society of America in 1951. The sediment is a silty clay with a sand content of about 6 per cent. The sand is mostly quartz with a number of reddish-brown silt-stone particles presumably reworked from an older formation. Occasional Foraminifera are found in this coarser fraction. The more common species are Elphidium clavatum Cushman, E. incertum (Williamson), and Quinqueloculina cf. lata Terquem or seminulum (Linnd). There were also a few reworked fossil species of the genera Gyroidina, Elphidium, and Cassidulina(?). These