DOI: 10.1016/j.quascirev.2015.12.017
Scopus记录号: 2-s2.0-84952700839
论文题名: Quantification of subaerial and episodic subglacial erosion rates on high latitude upland plateaus: Cumberland Peninsula, Baffin Island, Arctic Canada
作者: Margreth A. ; Gosse J.C. ; Dyke A.S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 133 起始页码: 108
结束页码: 129
语种: 英语
英文关键词: Arctic Canada
; Cold-based ice
; Episodic erosion
; Landscape evolution
; Subglacial plucking
; Terrestrial cosmogenic nuclides
; Tor
Scopus关键词: Erosion
; Glacial geology
; Isotopes
; Arctic Canada
; Landscape evolutions
; Subglacial plucking
; Terrestrial cosmogenic nuclides
; Tor
; Ice
英文摘要: Long-term rates of subaerial and episodic subglacial erosion by predominately cold-based ice cover are determined for tors on weathered plateaus on Cumberland Peninsula. By measuring terrestrial cosmogenic nuclide concentrations in differentially weathered surfaces on a given tor, we reconstruct the complex exposure and erosion history involving recurring cold-based ice cover. The style and rate of subaerial and subglacial erosion at multiple tor sites on Cumberland Peninsula are assessed with a Monte Carlo approach that computes plausible exposure histories based on a proxy record of global ice volume. Constant subaerial erosion rates by weathering are low (<2 mm ka-1), corroborated by nuclide concentrations measured on two tors located on coastal ridge crests that have likely never been glaciated. Summit plateaus intermittently covered by cold-based ice throughout the Quaternary have experienced episodic subglacial erosion by plucking of fractured bedrock with rates between 1 and 16 mm ka-1. Variation of episodic erosion rates is associated with topographic position of the sampled tors and bedrock fracture density. Most of the tors were last glacially plucked in pre-ultimate glaciations, not during the Wisconsinan glaciation. Furthermore, the new approach provides evidence for the extent of ice coverage during the late Wisconsinan, which is significant if no erratics are available for exposure dating. Despite late Pleistocene intervals of ice cover and glacial plucking, tor-studded landscapes of Cumberland Peninsula are of considerable antiquity. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59694
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth Sciences, Dalhousie University, Halifax, NS, Canada
Recommended Citation:
Margreth A.,Gosse J.C.,Dyke A.S.. Quantification of subaerial and episodic subglacial erosion rates on high latitude upland plateaus: Cumberland Peninsula, Baffin Island, Arctic Canada[J]. Quaternary Science Reviews,2016-01-01,133