DOI: 10.1016/j.quascirev.2015.03.021
Scopus记录号: 2-s2.0-84928106682
论文题名: Cosmogenic exposure age evidence for rapid Laurentide deglaciation of the Katahdin area, west-central Maine, USA, 16 to 15ka
作者: Davis P.T. ; Bierman P.R. ; Corbett L.B. ; Finkel R.C.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 116 起始页码: 95
结束页码: 105
语种: 英语
英文关键词: Calving ice margins
; Cirque glaciers
; Exposure dating
; Late-glacial climate
; Rapid ice retreat
Scopus关键词: Geochronology
; Glaciers
; Lakes
; Calving ice margins
; Continental ice sheet
; Exposure dating
; Glacial climate
; Laurentide deglaciation
; Laurentide ice sheets
; Rapid ice retreat
; St. lawrence lowlands
; Ice
; age determination
; bedrock
; boulder
; deglaciation
; elevation
; in situ measurement
; Laurentide Ice Sheet
; moraine
; mountain region
; uncertainty analysis
; Maine
; New England
; Penobscot River
; Saint Lawrence Lowlands
; United States
英文摘要: Katahdin, the highest peak in Maine and part of the second highest mountain range in New England, provides an opportunity to assess the timing and style of continental ice sheet surface lowering during deglaciation. We collected 14 samples from boulders on the adjacent Basin Ponds moraine, from bedrock and boulders on the upper part of the mountain, and from boulders in the surrounding area to estimate the age at which they were exposed by deglaciation of the Laurentide Ice Sheet. Measurements of in situ produced 10Be, which are consistent with measurements of 26Al, indicate that the Katahdin edifice became exposed from under ice by 15.3±2.1ka (n=6), an age indistinguishable from the adjacent Basin Ponds moraine (16.1±1.2ka, n=5). A boulder in the lowlands several km south of the moraine dates to 14.5±0.8ka, and a boulder deposited at Pineo Ridge, about 170km SE of Katahdin, dates to 17.5±1.1ka. These data show that samples collected over an elevation range of 1.6km and a distance of >170km all have exposure ages that are indistinguishable within uncertainties. Together these data suggest that the Laurentide Ice Sheet surface dropped rapidly and the ice sheet margin retreated quickly across Maine between about 16 and 15ka, perhaps influenced by calving of the marine-based ice sheet in the St. Lawrence Lowlands to the north and the Penobscot basin to the south. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59945
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Natural and Applied Sciences, Bentley University, Waltham, MA, United States; Geology Department and Rubenstein School of the Environment and Natural Resources, University of Vermont, Burlington, VT, United States; Department of Earth and Planetary Sciences, University of California, Berkeley, CA, United States; Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA, United States
Recommended Citation:
Davis P.T.,Bierman P.R.,Corbett L.B.,et al. Cosmogenic exposure age evidence for rapid Laurentide deglaciation of the Katahdin area, west-central Maine, USA, 16 to 15ka[J]. Quaternary Science Reviews,2015-01-01,116