Late Quaternary terrigenous sedimentation in the Western Arctic Ocean as exemplified by a sedimentary record from the Alpha Ridge

Weinan, Liu and Rujian, Wang and Jianfang, Chen and Zhenbo, Cheng and Zhihua, Chen and Yechen, Sun (2011) Late Quaternary terrigenous sedimentation in the Western Arctic Ocean as exemplified by a sedimentary record from the Alpha Ridge. Advances in Polar Science, 22 (4). pp. 215-222.

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Abstract

Terrigenous components in sediment core B84A from the Alpha Ridge, Western Arctic Ocean, have been investigated to reconstruct Mid to Late Quaternary variations in sedimentation, provenance, and related climate changes. The core stratigraphy, evaluated by a combination of variations in Mn content, color cycles, foraminiferal abundance, and lithological correlation, extends back to estimated Marine Isotope Stage 12. Twelve Ice Rafted Detritus (IRD, >250 ¹m) events were identified and interpreted to mostly occur during deglaciation. The Canadian Arctic, which was covered by ice sheets during glacial periods, is suggested to be the major source region. The IRD events likely indicate the collapses of ice sheets, possibly in response to abrupt climate changes. Grain size analysis of B84A indicates sedimentologically sensitive components in core B84A in the 4{9 ¹m and 19{53 ¹m silt subfractions, which are inferred to be mainly transported by currents and sea ice, respectively. Down core variability of these two fractions may indicate changes in ice drift and current strength. In accordance with previous studies in the central Arctic Ocean, the average sedimentation rate in core B84A is about 0.4 cm*ka(-1). Compared with the relatively high sedimentation rates on the margins, sedimentation in the central Arctic Ocean is limited by sea ice cover and the correspondingly low bioproductivity, as well as the long distance from source regions of terrigenous sediment.

Item Type:	Article
Related URLs:
Keywords:	IRD event, terrigenous component, sedimentation rate, Arctic Ocean, Alpha Ridge, Quaternary
Subjects:	Natural Environment > Oceans Natural Environment > Terrestrial
Organizations:	Unspecified
Date Deposited:	20 Sep 2023 11:51
URI:	http://library.arcticportal.org/id/eprint/2431

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