气候变化领域集成服务门户(CCPortal): Multiple meltwater discharge and ice rafting events recorded in the deglacial sediments along the Beaufort Margin; Arctic Ocean

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DOI	10.1016/j.quascirev.2018.11.014
	Multiple meltwater discharge and ice rafting events recorded in the deglacial sediments along the Beaufort Margin; Arctic Ocean
	Klotsko S.; Driscoll N.; Keigwin L.
发表日期	2019
ISSN	0277-3791
起始页码	185
结束页码	208
卷号	203
英文摘要	The first regional model for the deglacial history of the Beaufort margin slope, in the western Arctic, is presented. The conceptual model was developed using new high-resolution CHIRP seismic reflection, multibeam bathymetry, and sediment core data acquired along the margin. This synthesis provides important constraints on sediment source and dispersal patterns for the last deglaciation. The continental slope from Barrow Canyon to the Mackenzie Trough is characterized by thick Holocene sediments mostly sourced from Barrow Canyon and continental discharge. This acoustically transparent, fine-grained unit overlies acoustically laminated sediments sourced from the Mackenzie River and ice rafting. The deglacial history of the margin from Mackenzie Trough to the Amundsen Gulf is characterized by many ice rafting and meltwater discharge events. Ice rafted debris layers were deposited around ∼14.6 ka and ∼14.1 ka and likely document enhanced ice shedding events from the Amundsen and M'Clure ice streams as they retreated. There are three inferred meltwater discharge events, all sourced from the Mackenzie region. The oldest discharge event had two phases, one sometime between ∼14.5 ka and ∼14.2 ka and another between ∼14.0 ka and ∼13.0 ka. This discharge deposited finely laminated sediments more than 7 m thick sourced from proglacial lakes in the area. Following this was a flood event starting at ∼12.94 ka, which generated high amplitude reflectors, deposited coarse debris, and caused a lowering in the δ18O record. This is possibly a major outburst flood from glacial Lake Agassiz with an additional component of Agassiz meltwater that was diverted from its southern drainage pathway down the Mississippi to the Gulf of Mexico. Finally, a third discharge event was initiated by ∼11.3 ka, which deposited coarse laminated sediments focused in the Mackenzie Trough. Timing of these second and third events correlates with the onset of the Younger Dryas cold period and the preBoreal oscillation event, respectively, suggesting that fresh water discharge may have reached a tipping point, leading to those climate events. © 2018 Elsevier Ltd
英文关键词	Arctic Ocean; Beaufort margin; CHIRP; Glaciation; Grain size; Mackenzie river; Quaternary; Sedimentology-marine cores; Seismic reflection
语种	英语
scopus关键词	Bathymetry; Debris; Floods; Glacial geology; Ice; Lakes; Rivers; Seismic waves; Seismology; Arctic ocean; Beaufort margin; CHIRP; Glaciation; Grain size; Marine cores; Quaternary; Seismic reflections; Sediments; continental slope; discharge; Glacial Lake Agassiz; glaciation; grain size; ice rafting; ice-rafted debris; lamination; last deglaciation; meltwater; proglacial environment; Quaternary; sedimentology; seismic reflection; source apportionment; Younger Dryas; Amundsen Gulf; Arctic Ocean; Atlantic Ocean; Beaufort Sea; Canada; Gulf of Mexico; Mackenzie River [Northwest Territories]; Mackenzie Trough; Mississippi; Northwest Territories; United States
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/152066
作者单位	Scripps Institution of Oceanography, UC San Diego, La Jolla, CA 92093, United States; Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States; Department of Geological Sciences, San Diego State University, San Diego, CA 92182, United States
推荐引用方式 GB/T 7714	Klotsko S.,Driscoll N.,Keigwin L.. Multiple meltwater discharge and ice rafting events recorded in the deglacial sediments along the Beaufort Margin; Arctic Ocean[J],2019,203.
APA	Klotsko S.,Driscoll N.,&Keigwin L..(2019).Multiple meltwater discharge and ice rafting events recorded in the deglacial sediments along the Beaufort Margin; Arctic Ocean.Quaternary Science Reviews,203.
MLA	Klotsko S.,et al."Multiple meltwater discharge and ice rafting events recorded in the deglacial sediments along the Beaufort Margin; Arctic Ocean".Quaternary Science Reviews 203(2019).