Sedimentary record from the Canada Basin, Arctic Ocean: implications for late to middle Pleistocene glacial history

Linsen Dong,Xuefa Shi,Yanguang Liu,Jianxing Liu,Yuanhui Huang,Kunshan Wang,Jianjun Zou,Xuchen Wang,Leonid Polyak,Xisheng Fang,Fuqiang Sun

doi:10.5194/cp-13-511-2017

Abstract

Abstract. Sediment core ARC4-BN05 collected from the Canada Basin, Arctic Ocean, covers the late to middle Quaternary (Marine Isotope Stage – MIS – 1–15, ca. 0.5–0.6 Ma) as estimated by correlation to earlier proposed Arctic Ocean stratigraphies and AMS14C dating of the youngest sediments. Detailed examination of clay and bulk mineralogy along with grain size, content of Ca and Mn, and planktic foraminiferal numbers in core ARC4–BN05 provides important new information about sedimentary environments and provenance. We use increased contents of coarse debris as an indicator of glacier collapse events at the margins of the western Arctic Ocean, and identify the provenance of these events from mineralogical composition. Notably, peaks of dolomite debris, including large dropstones, track the Laurentide Ice Sheet (LIS) discharge events to the Arctic Ocean. Major LIS inputs occurred during the stratigraphic intervals estimated as MIS 3, intra-MIS 5 and 7 events, MIS 8, and MIS 10. Inputs from the East Siberian Ice Sheet (ESIS) are inferred from peaks of smectite, kaolinite, and chlorite associated with coarse sediment. Major ESIS sedimentary events occurred in the intervals estimated as MIS 4, MIS 6 and MIS 12. Differences in LIS vs. ESIS inputs can be explained by ice-sheet configurations at different sea levels, sediment delivery mechanisms (iceberg rafting, suspension plumes, and debris flows), and surface circulation. A long-term change in the pattern of sediment inputs, with an apparent step change near the estimated MIS 7–8 boundary (ca. 0.25 Ma), presumably indicates an overall glacial expansion at the western Arctic margins, especially in North America.

Highlights

The advances and decays of continental ice sheets play a significant role in the alteration of global climatic system, such as changing atmospheric circulations, creating largearea albedo anomalies and regulating the global sea level fluctuations (Clark et al, 1990)
We present a multiproxy study of glacial– interglacial changes during the late to middle Pleistocene based on sediment core ARC4-BN05 from the Canada Basin north of the Chukchi Plateau and east of the Mendeleev Ridge (Fig. 1)
As common for sediment cores from the Arctic Ocean (e.g., Jakobsson et al, 2000; Polyak et al, 2004, 2009; Spielhagen et al, 2004; Stein et al, 2010a, b), core ARC4-BN05 displays distinct cycles in sediment color and composition expressed in interlamination of dark-brownish and lightercolored grayish muds, with coarser dropstones occurring in several layers

Summary

Introduction

The advances and decays of continental ice sheets play a significant role in the alteration of global climatic system, such as changing atmospheric circulations, creating largearea albedo anomalies and regulating the global sea level fluctuations (Clark et al, 1990). Studies of Pleistocene glaciations around the Arctic Ocean dealt mostly with the late Quaternary history of the Eurasian Ice Sheet during Marine Isotope Stages (MIS) 1–6 (e.g., Svendsen et al.,2004; Larsen et al, 2006) or the Laurentide Ice Sheet (LIS) with a special attention to the Last Glacial Maximum (LGM) (e.g., Dyke et al, 2002; England et al, 2009). In addition to terrestrial data, studies of sediment cores from the Arctic Ocean are critical for comprehending the history of glacial advances and retreats (e.g., Polyak et al, 2004, 2009; Spielhagen et al, 2004; Stein et al, 2012; Kaparulina et al, 2016).

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Discussion

Conclusion