| This study compares productivity records from two different proxies, nannofossil Sr/Ca as an indicator of surface ocean primary productivity and benthic foraminiferal accumulation rates (BFAR) as an indicator of consumption at the seafloor, using late Miocene-early Pliocene sediments from Ocean Drilling Program (ODP) cores at Atlantic Ocean Sites 982 and 925. The research provides the unique opportunity to relate multiple aspects, both physical and geochemical in nature, from a single set of synchronous samples in order to reconstruct paleoproductivity. Despite a number of uncertainties uniquely related to each proxy, the productivity reconstructions share numerous similarities. Records from both sites show a marked increase in productivity in the long term trend during the study interval, including increasing values of BFAR [Diester-Haas et al., in press] and bulk (0.8 to 20.0 mum) nannofossil Sr/Ca at ∼5 Ma at Site 982, and an increase in measured BFAR [Diester-Haas et al., in press] and fine fraction (0.8 to 8.0 mum) Sr/Ca that are synchronous at ∼6 Ma at Site 925. (Abstract shortened by UMI.)... |
