Impact of melting of the Laurentide Ice Sheet on sediments from the upper continental slope off southeastern Canada: evidence from Sm-Nd isotopes

doi:10.1139/E08-031

	Impact of melting of the Laurentide Ice Sheet on sediments from the upper continental slope off southeastern Canada: evidence from Sm-Nd isotopes
	Stevenson, R. K.1; Meng, X. W.1,2; Hillaire-Marcel, C.1
刊名	CANADIAN JOURNAL OF EARTH SCIENCES
	2008-11
卷号	45 期号:11 页码:1243-1252
ISSN号	0008-4077
DOI	10.1139/E08-031
英文摘要	We present new Sm-Nd isotope data for sediments from a core located on the continental slope of the St. Pierre Bank of Canada's east coast. The Nd analyses indicate that the sediments were derived from two principal sources: the North American Shield that yields an average early Proterozoic isotopic signature and a younger Proterozoic signature attributed to Appalachian crustal sources. The Appalachian-sourced sediments predominated during the last glacial maximum (LGM) and were associated with low sedimentation rates (<30 cm/ka), with the exception of a strong North American Shield signature present in a detrital carbonate layer that corresponds to Heinrich Layer 1 (H 1). The dominance of the Appalachian signature decreased Subsequent to HI. The Appalachian signatures closely follow the distribution of sediments interpreted as locally derived glacial tills, while the North American Shield signatures follow the distribution of hemipelagic mud that was likely deposited by the Labrador Current. The Nd data are consistent with the persistence of the Wisconsinan Ice Sheet coverage of Newfoundland and the Grand Banks after the LGM, although the coverage began to wane prior to 12.5 ka as evidenced by the increasing influence of the Labrador Current. However, an increase in the Appalachian isotope signature at the close of the Younger Dryas event likely indicates the final melting of the ice sheet covering the Grand Banks and the Avalon Peninsula, and the initiation of the Labrador Current's modern circulation pathway.
WOS关键词	LAST GLACIAL MAXIMUM ; NORTHERN NORTH-ATLANTIC ; LABRADOR SEA SEDIMENTS ; DEEP CIRCULATION ; EASTERN CANADA ; YOUNGER DRYAS ; WESTERN BOUNDARY ; AR-40/AR-39 AGES ; HEINRICH LAYERS ; ST-LAWRENCE
WOS研究方向	Geology
语种	英语
出版者	NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS
WOS记录号	WOS:000265847200005
内容类型	期刊论文
源URL	[http://ir.fio.com.cn:8080/handle/2SI8HI0U/26365]
专题	自然资源部第一海洋研究所
通讯作者	Stevenson, R. K.
作者单位	1.Univ Quebec, Geotop, Stn Ctr Ville, Montreal, PQ H3C 3P8, Canada 2.SOA, Inst Oceanog 1, Qingdao 266061, Peoples R China
推荐引用方式 GB/T 7714	Stevenson, R. K.,Meng, X. W.,Hillaire-Marcel, C.. Impact of melting of the Laurentide Ice Sheet on sediments from the upper continental slope off southeastern Canada: evidence from Sm-Nd isotopes[J]. CANADIAN JOURNAL OF EARTH SCIENCES,2008,45(11):1243-1252.
APA	Stevenson, R. K.,Meng, X. W.,&Hillaire-Marcel, C..(2008).Impact of melting of the Laurentide Ice Sheet on sediments from the upper continental slope off southeastern Canada: evidence from Sm-Nd isotopes.CANADIAN JOURNAL OF EARTH SCIENCES,45(11),1243-1252.
MLA	Stevenson, R. K.,et al."Impact of melting of the Laurentide Ice Sheet on sediments from the upper continental slope off southeastern Canada: evidence from Sm-Nd isotopes".CANADIAN JOURNAL OF EARTH SCIENCES 45.11(2008):1243-1252.