BIOGENETIC BARIUM DISTRIBUTION IN EQUATORIAL NORTHEASTERN PACIFIC SEDIMENTS

Ba, Ti, Al and organic carbon contents of sediments from the abyssal Equatorial Northeastern Pacific were analyzed by ICP-AES and Elements Analyzer respectively. The Ba content varied between 0.198% and 0.792%. Biogenic barium(Ba_bio) calculated using normative calculation varied between 0.162% and 0.764%, which was up to 81.6% and 96.5% of total barium in the sediments. The Ba_bio distributions in sediment profile show little variation in the upper sections,but large variations in lower sections. This suggests that the sediment setting perhaps changed since Tertiary in the region. The organic carbon(C_org) contents varied between 0.18% and 0.58%, and decreased with sediment depth increasing. The Ba_bio/Ti ratio in eastern zone sediments is higher than that of western zone. The Ba_bio/Ti ratio also decreased with latitude increasing in the area. The C_org/Ti ratio and Ba_bio/Ti ratio display negative correlation,suggesting that there is little obvious correlation between surface oceanic nutrition level and Ba_bio contents of sediments in the region. So we should pay more attention to the application of biogenetic barium to paleoproductivity research.