Paleoproductivity and paleoceanography of the last 4.3 Myrs at IODP Expedition 323 Site U1341 in the Bering Sea based on biogenic opal content

Online Access: Get full text
doi: 10.1016/j.dsr2.2015.04.005
Author(s): Iwasaki, Shinya; Takahashi, Kozo; Kanematsu, Yoshiyuki; Asahi, Hirofumi; Onodera, Jonaotaro; Ravelo, A. Christina
Author Affiliation(s): Primary:
Kyushu University, Department of Earth and Planetary Sciences, Fukuoka, Japan
Korea Polar Research Institute, South Korea
Japan Agency for Marine-Earth Science and Technology, Japan
University of California at Santa Cruz, United States
Volume Title: Plio-Pleistocene paleoceanography of the Bering Sea
Volume Author(s): Takahashi, Kozo, editor; Ravelo, A. Christina; Okazaki, Yusuke
Source: Plio-Pleistocene paleoceanography of the Bering Sea, edited by Kozo Takahashi, A. Christina Ravelo and Yusuke Okazaki. Deep-Sea Research. Part II: Topical Studies in Oceanography, Vol.125-126, p.145-154. Publisher: Elsevier, Oxford, International. ISSN: 0967-0645
Note: In English. 55 refs.; illus., incl. 2 tables, sketch map
Summary: Site U1341 in the southern Bering Sea was drilled and cored down to 600 meters below sea-floor (mbsf) during Integrated Ocean Drilling Program (IODP) Expedition 323, covering a nearly complete record of the last 4.3 million years (Myrs). Analyses of the biogenic opal content of sediments at the site provide detailed and useful information on past biological productivity and paleoceanographic changes that occurred in the region including shifts in the oceanographic condition during the intensification of the Northern Hemisphere Glaciation (NHG) and the Mid-Pleistocene Transition (MPT). An overall decreasing trend in the %biogenic opal record, combined with evidence from microfossil assemblages, indicates a gradual shift in environmental conditions during the last 4.3 Myrs, from warm and nutrient-rich conditions to cool conditions with sea-ice. On the other hand, biogenic opal mass accumulation rates (MAR) were high during 2.6-2.1 Ma after the intensification of the NHG, unlike in the western North Pacific. High biological productivity during this specific interval is consistent with the results of previous studies in the other Marginal Seas, possibly suggesting that iron leakage from the Bering Continental Shelf occurred. After the MPT, the data suggest that there was sea-ice expansion and discharge of lithogenic matter during glacial periods, and high productivity during interglacial periods. Abstract Copyright (2016) Elsevier, B.V.
Year of Publication: 2016
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Bering Sea; Biogenic processes; Bowers Ridge; Cenozoic; Cores; Detroit Seamount; Emperor Seamounts; Expedition 323; Framework silicates; IODP Site U1341; Integrated Ocean Drilling Program; Leg 145; Lithofacies; Lithostratigraphy; Marine environment; Neogene; North Pacific; Northwest Pacific; ODP Site 882; Ocean Drilling Program; Opal; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Pleistocene; Pliocene; Productivity; Quaternary; Reconstruction; Silica minerals; Silicates; Tertiary; West Pacific
Coordinates: N540200 N540200 E1790031 E1790031
N502148 N502148 E1673600 E1673600
Record ID: 2017013132
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands