In:
Island Arc, Wiley, Vol. 15, No. 3 ( 2006-09), p. 366-377
Abstract:
Abstract A continuous, well‐preserved core was obtained from the Choshi area, on the Pacific side of Japan, to investigate paleoceanographic and paleoclimatic changes around the northwestern Pacific region during the middle Pleistocene. Siliciclastic sequences in the core are divided into five formations – the Obama, Yokone, Kurahashi and Toyosato Formations in the Inubo Group and the Katori Formation, in ascending order. Examination of calcareous nannofossils and magnetic polarities detected four datums in the core sediments of the Inubo Group: the top of Reticulofenestra asanoi , the base of Helicosphaera inversa , the top of Pseudoemiliania lacunosa and the Brunhes–Matuyama boundary. Fourteen marine isotope stages (MIS24–MIS11) were identified in the δ 18 O and δ 13 C records based on detected datums and the graphic correlation with the standard stack oxygen isotope curve. Magnetic susceptibility and gamma‐ray attenuation porosity evaluator density were also measured and low values characterize the glacial intervals. Biogenic sedimentation by primary production may be larger during the glacial periods because of invasions of nutrient‐rich northern surface‐waters related to the southward shift of the Kuroshio front in the Choshi area.
Type of Medium:
Online Resource
ISSN:
1038-4871
,
1440-1738
DOI:
10.1111/iar.2006.15.issue-3
DOI:
10.1111/j.1440-1738.2006.00535.x
Language:
English
Publisher:
Wiley
Publication Date:
2006
detail.hit.zdb_id:
1495883-1
detail.hit.zdb_id:
2020960-5
SSG:
13
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