| DOI: | 10.1016/j.quascirev.2018.12.014
|
| Scopus记录号: | 2-s2.0-85059348909
|
| 论文题名: | Analysis of multiple cosmogenic nuclides constrains Laurentide Ice Sheet history and process on Mt. Mansfield, Vermont's highest peak |
| 作者: | 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.
|
| 刊名: | Quaternary Science Reviews
|
| ISSN: | 2773791
|
| 出版年: | 2019
|
| 卷: | 205 | | 起始页码: | 234
|
| 结束页码: | 246
|
| 语种: | 英语
|
| 英文关键词: | Cosmogenic isotopes
; Erosion
; Geochronology
; Glaciation
; Last glacial maximum
; North America
; Pleistocene
|
| 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
|
| 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 |
| Citation statistics: |
|
| 资源类型: | 期刊论文
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/117393
|
| Appears in Collections: | 气候变化与战略
|
|
There are no files associated with this item.
|
| Recommended Citation: | |
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]. Quaternary Science Reviews,2019-01-01,205
|
|
|