This study describes molecular organic geochemical investigations of 14 samples from Site 903 off New Jersey, as well as bulk analysis of a great number of sediments from Sites 903 and 905. Detailed lipid analysis of the solvent-extractable organic matter exhibits a complex assemblage of marine, terrigenous, and bacterial compounds. n-Alkanes and n-alcohols are the most abundant compounds in extracts of sediments from Site 903, followed by steroidal alcohols in considerably smaller concentrations that decrease with depth. Analysis of long-chain unsaturated ketones for reconstruction of paleo-sea surface temperature results in an average water temperature estimate of 25°C since the middle Miocene. The results indicate continuous supply of terrigenous organic material to the region with occasional conditions of better marine organic matter preservation, particularly in Oligocene to middle Miocene times. Some variations in organic matter composition may be caused by sea-level changes. A warm current analogous to the present Gulf Stream appears to have existed off New Jersey at least since the Oligocene.

Date of initial receipt: 13 March 1995
Date of acceptance: 8 December 1995

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