Argon composition and new combined chronologies of ODP Sites 185-1149 and 191-1179

Despite the different scientific objectives of Legs 185 and 191, the sedimentary sections recovered from Sites 1149 and 1179 are the two most complete sections recovered from the northwestern Pacific Basin by either the Deep Sea Drilling Project (DSDP) (i.e., Legs 6, 20, 32, and 86) or ODP (i.e., Legs 185 and 191). During Leg 185, a complete sedimentary section (410 m) and an additional 133 m of highly altered volcanic basement were recovered. The Miocene to Pleistocene section (i.e., upper ~150 m) recovered from Site 1149 includes lithostratigraphic Unit I (0-118.2 meters below sea floor [mbsf]) and Subunit IIA (118.2-149.5 mbsf) of Plank, Ludden, Escutia, et al. (2000, doi:10.2973/odp.proc.ir.185.2000) and consists of ash- and biogenic silica- bearing clay, radiolarian-bearing clay, silt-bearing clay, ash-bearing siliceous ooze, and diatomaceous clay, with numerous discrete volcanic ash layers (Plank, Ludden, Escutia, et al., 2000, doi:10.2973/odp.proc.ir.185.2000). During Leg 191, a near-continuous 375-m-thick sedimentary section was recovered in addition to 100 m of basaltic basement. The upper 221.5 m of the sedimentary section at Site 1179 (i.e., within lithostratigraphic Unit I of Kanazawa, Sager, Escutia et al. [2001, doi:10.2973/odp.proc.ir.191.2001]) consists of upper Miocene to Pleistocene clay- and radiolarian-bearing diatom ooze containing numerous discrete ash layers. The presence of discrete ash layers within the Miocene to Pleistocene sedimentary section at both Site 1149 and 1179 provides a unique opportunity to conduct 40Ar/39Ar ash chronology to refine the excellent magnetostratigraphic records (based on the scale of Berggren et al., 1995) obtained shipboard from both sites (Plank, Ludden, Escutia, et al., 2000, doi:10.2973/odp.proc.ir.185.2000; Kanazawa, Sager, Escutia, et al., 2001, doi:10.2973/odp.proc.ir.191.2001).In this data report we present the analytical results from the 40Ar/39Ar incrementally heated analyses and provide a new combined late Miocene to Pleistocene 40Ar/39Ar and magnetostratigraphic chronology for the northwestern Pacific.

The Global Plankton Database: an inventory and data from the Former Soviet Union expeditions

At present time, there is a lack of knowledge on the interannual climate-related variability of zooplankton communities of the tropical Atlantic, central Mediterranean Sea, Caspian Sea, and Aral Sea, due to the absence of appropriate databases. In the mid latitudes, the North Atlantic Oscillation (NAO) is the dominant mode of atmospheric fluctuations over eastern North America, the northern Atlantic Ocean and Europe. Therefore, one of the issues that need to be addressed through data synthesis is the evaluation of interannual patterns in species abundance and species diversity over these regions in regard to the NAO. The database has been used to investigate the ecological role of the NAO in interannual variations of mesozooplankton abundance and biomass along the zonal array of the NAO influence. Basic approach to the proposed research involved: (1) development of co-operation between experts and data holders in Ukraine, Russia, Kazakhstan, Azerbaijan, UK, and USA to rescue and compile the oceanographic data sets and release them on CD-ROM, (2) organization and compilation of a database based on FSU cruises to the above regions, (3) analysis of the basin-scale interannual variability of the zooplankton species abundance, biomass, and species diversity.