1. Glacial-interglacial sedimentation and paleocirculation at the Northwind Ridge, western Arctic Ocean.
- Author
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Wang, Rong, Polyak, Leonid, Zhang, Weiyan, Yu, Xiaoguo, Ye, Liming, Dong, Linsen, Liu, Yanguang, Wang, Weiguo, and Diekmann, Bernhard
- Subjects
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ICE sheets , *INTERGLACIALS , *ICE streams , *SEDIMENTATION & deposition , *OCEAN , *SEA ice , *PROVENANCE (Geology) - Abstract
Sediment cores from the Northwind Ridge north of the Arctic Chukchi-Alaskan margin were analyzed for a suite of stratigraphic and provenance proxies. Based on the correlation to previously studied regional records, cores under study present sedimentary environments of Marine Isotope Stages (MIS) 1–11 (∼0.4 Ma) on millennial time scales. Contrasting glacial-interglacial conditions and provenance were characterized by means of clay-mineral and geochemical (elemental and isotopic) proxies along with grain size. Interglacial environments are interpreted as sea-ice dominated, with pre-Holocene sediment transported mostly from the East Siberian to Chukchi-Alaskan margin. In comparison with the recent conditions, this pattern suggests a stronger Transpolar Drift expanding into the Canada Basin at the expense of the Beaufort Gyre, or stronger along-shelf currents. Glacial intervals prior to MIS4 have a predominantly North American signature with carbonaceous or terrigenous source rocks. Carbonaceous inputs marked by Ca peaks are tracked to the western Canadian Arctic Archipelago eroded by the Laurentide Ice Sheet (LIS). Terrigenous sources (Zr peaks) are likely related to areas impacted by the Innuitian Ice Sheet and/or the LIS Mackenzie ice stream. MIS 4 and 2 intervals have a different composition with the Siberian/Chukchi rather than North American provenance. A stronger winnowing indicated by grain size in the glacial intervals suggests a stronger mid-depth circulation. Study results provide new boundary conditions for modeling paleocirculation and glaciations in the western Arctic Ocean. • Contrasting glacial-interglacial conditions and provenance were characterized. • Pre-Holocene interglacials have sea-ice dominated depositional environment, margin provenance and a stronger TPD. • Glacial intervals prior to MIS4 have a predominantly North American signature with carbonaceous or terrigenous rocks. • MIS4 and 2 intervals have more interglacial compositions with the Siberian/Chukchi rather than North American source. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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