Nitrogen isotopes of sinking matter and sediments in the South Atlantic.

Abstract

The 14N/J5N ratio were measured on sinking matter, atmospheric dust and sediments in the equatorial and eastern South Atlantic. To determine the main controls on the nitrogen composition of the marine sediment in this region for the present situation, sediment traps and surface sediments were analysed and compared to other parameters and independent oceanographic and climatic data. Additionally, to better estimate the possible impact from the terrigenous input on the deep sea sediments, shipboard collected dust samples were analysed for their isotopic composition. For reconstructions of past changes in the high production zone in the Benguela upwelling regime, a eore transect off Namibia, South West Africa, were analysed for downcore variations in the q15N signal.