DISTRIBUTIONS OF LONG-CHAIN ALKENONES AND ALKYL ALKENOATES IN MARINE SURFACE SEDIMENTS FROM THE NORTH-EAST ATLANTIC

The abundances of long-chain alkenones and alkyl alkenoates are report ed for a suite of surface sediments from the NE Atlantic (0 degrees-75 degrees N). Despite the differing conditions of their biologies and d iffering extents of water column degradation and of early diagenesis i n the sediments, the degree of unsaturation of the alkenones (e.g. the U-37(k) parameter), and the relative proportion of alkyl alkenoates t o alkenones display linear correlations with average temperature for s urface waters warmer than 5 degrees C. There is evidence that the chai n-length distribution of the alkenones and of the ratio between the et hyl and methyl C-38 alkenones are species dependent, which would enabl e their use as chemotaxonomic tools.