9526356 Altabet The authors propose to explore the potential of stable nitrogen isotopes in marine sediments as tracers of past nitrate utilization, and hence of primary production. They will examine the difference between water-column and surface sediment ratios, explore the feasibility of analyzing organic material in the matrices of individual microfossils, and will examine a typical sediment record from the equatorial Pacific to determine whether the changes seen from glacial to interglacial periods might be only an artifact of differential preservation.
