气候变化领域集成服务门户(CCPortal): Analysis of multiple cosmogenic nuclides constrains Laurentide Ice Sheet history and process on Mt. Mansfield; Vermont's highest peak

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DOI	10.1016/j.quascirev.2018.12.014
	Analysis of multiple cosmogenic nuclides constrains Laurentide Ice Sheet history and process on Mt. Mansfield; Vermont's highest peak
	Corbett L.B.; Bierman P.R.; Wright S.F.; Shakun J.D.; Davis P.T.; Goehring B.M.; Halsted C.T.; Koester A.J.; Caffee M.W.; Zimmerman S.R.
发表日期	2019
ISSN	0277-3791
起始页码	234
结束页码	246
卷号	205
英文摘要	Constraining glacial history and process on Mt Mansfield, the highest peak in Vermont (1339 m a.s.l.), provides insight into how the Laurentide Ice Sheet shaped the underlying landscape, when latest Pleistocene ice retreated, and how upland and lowland glacial histories relate. Here, we quantify in situ cosmogenic 10 Be in 20 bedrock and boulder surfaces, as well as in situ cosmogenic 14 C in three of those surfaces, to assess subglacial erosion and exposure history. Isotopic concentrations indicate that Mt. Mansfield's lower elevations (∼400–1200 m a.s.l.) were deeply eroded by at least several meters during the last glaciation and then deglaciated rapidly; 10 Be ages across this elevation span are indistinguishable and average 13.9 ± 0.6 ka (n = 15), suggesting that 800 m of ice thinning occurred within at most about a millennium. Conversely, the higher elevations (>1200 m a.s.l.) preserve a more complex geomorphic history. Mt. Mansfield's summit surfaces contain 10 Be from previous periods of exposure, indicating that the mountaintop landscapes were likely preserved beneath cold-based, weakly-erosive glacial ice. Exposure ages from the shorter-lived isotope, 14 C, are younger (9.7 and 11.7 ka), suggesting that Mt. Mansfield's summit was covered until the early Holocene, perhaps by snowfields, ice carapaces, and/or till. Our findings, in context of previous work, suggest that thinning Laurentide ice flowed through the valleys for at most hundreds of years following deglaciation of the uplands, but that the summit remained shielded by ice or sediment for millennia after the valleys became ice-free. © 2018 Elsevier Ltd
英文关键词	Cosmogenic isotopes; Erosion; Geochronology; Glaciation; Last glacial maximum; North America; Pleistocene
语种	英语
scopus关键词	Erosion; Geochronology; Glacial geology; Glaciers; Isotopes; Landforms; Cosmogenic isotopes; Glaciation; Last Glacial Maximum; North America; Pleistocene; Ice; bedrock; beryllium isotope; boulder; carbon isotope; cosmogenic radionuclide; deglaciation; geochronology; glacial erosion; glacial history; isotopic composition; last glaciation; Laurentide Ice Sheet; Pleistocene; thinning; upland region; Appalachians; Green Mountains; Mount Mansfield; North America; United States; Vermont; Vermont
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/152031
作者单位	Department of Geology, University of Vermont, Burlington, VT, United States; Department of Earth and Environmental Sciences, Boston College, Boston, MA, United States; Department of Natural and Applied Science, Bentley University, Waltham, MA, United States; Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA, United States; Department of Physics and Astronomy, Purdue University, West Lafayette, IN, United States; Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, United States; Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA, United States
推荐引用方式 GB/T 7714	Corbett L.B.,Bierman P.R.,Wright S.F.,et al. Analysis of multiple cosmogenic nuclides constrains Laurentide Ice Sheet history and process on Mt. Mansfield; Vermont's highest peak[J],2019,205.
APA	Corbett L.B..,Bierman P.R..,Wright S.F..,Shakun J.D..,Davis P.T..,...&Zimmerman S.R..(2019).Analysis of multiple cosmogenic nuclides constrains Laurentide Ice Sheet history and process on Mt. Mansfield; Vermont's highest peak.Quaternary Science Reviews,205.
MLA	Corbett L.B.,et al."Analysis of multiple cosmogenic nuclides constrains Laurentide Ice Sheet history and process on Mt. Mansfield; Vermont's highest peak".Quaternary Science Reviews 205(2019).