Variations in the provenance of sediment from ice sheets surrounding Baffin Bay during MIS 2 and 3 and export to the Labrador Shelf Sea: site HU2008029-0008 Davis Strait
Variations in the provenance of sediment from ice sheets surrounding Baffin Bay during MIS 2 and 3 and export to the Labrador Shelf Sea: site HU2008029-0008 Davis Strait
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DOI：
10.1002/jqs.2643
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发表时间：
2014-01-01
影响因子：
2.3
通讯作者：
Simon, Quentin
中科院分区：
文献类型：
--
作者：
Andrews, John T.;Gibb, Olivia T.;Simon, Quentin
基于对位于戴维斯海峡海床以南的HU2008029-0006/0008(水深857m)岩芯的X射线衍射定量矿物学分析，我们寻求两个问题的答案：(1)拉布拉多西北陆架海Heinrich(H-)和巴芬湾碎屑碳酸盐(BBDC)事件的时间相关性；(2)沉积物的来源？沉积物分解模型(SedUnMix)用于确定物源变化。尽管获得了12个放射性碳测年数据，但仍有许多年龄倒转，我们倾向于HU2008029-0008PC的深度/年龄模型，该模型基于与戴维斯海峡北部和南部测年良好的相邻岩心的相关性。我们发现除了H-0事件外，H-0事件与BBDC事件之间没有相关性，H-0事件似乎是沿着加拿大东北边缘的一个大致同步的事件，并且与沿Laurentide冰盖这一侧翼的主要冰川建造事件相关。基于六个潜在冰源区的沉积物成分分解表明，0008PC的大部分沉积物来自西格陵兰岛的冰川侵蚀，但其间有来自巴芬湾以北露头的富含白云石的沉积物主导成分。这些BBDC事件的估计日期约为13、25和30-38卡BP。版权所有(C)2013 John Wiley&Sons，Ltd.
Based on quantitative X-ray diffraction mineralogical analysis of cores HU2008029-0006/0008 (857-m water depth) located south of the Davis Strait sill, we seek answers to two questions: (i) the temporal correlation of NW Labrador Shelf Sea Heinrich (H-) and Baffin Bay detrital carbonate (BBDC) events, and (ii) the provenance of the sediments? A sediment-unmixing model (SedUnMix) is used to determine provenance variations. Although 12 radiocarbon dates were obtained there were many age reversals and we favour a depth/age model for HU2008029-0008PC based on correlations to well-dated neighbouring cores north and south of Davis Strait. We find no correlation between H- and BBDC events except for H-0, which appears to be a broadly synchronous event along the NE Canadian margin and is correlative with an episode of major moraine building along this flank of the Laurentide Ice Sheet. Unmixing of the sediment composition based on six potential glacial source regions indicates that the bulk of the sediment in 0008PC is derived from glacial erosion of West Greenland, but is punctuated by intervals when dolomite-rich sediments, derived from outcrops north of Baffin Bay, dominate the composition. Estimated dates on these BBDC events are approximate to 13, 25 and 30-38 cal ka BP. Copyright (C) 2013 John Wiley & Sons, Ltd.