DOI: 10.1016/j.epsl.2021.117009
论文题名: Rapid erosion of the central Transantarctic Mountains at the Eocene-Oligocene transition: Evidence from skewed (U-Th)/He date distributions near Beardmore Glacier
作者: He J. ; Thomson S.N. ; Reiners P.W. ; Hemming S.R. ; Licht K.J.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 567 语种: 英语
中文关键词: apatite helium thermochronology
; East Antarctic ice sheet
; glacial erosion
; overdispersion
; subglacial landscape
英文关键词: Apatite
; Dispersions
; Glacial geology
; Helium
; Probability distributions
; Apatite helium thermochronology
; Cryosphere
; East antarctic ice sheets
; Glacial erosion
; Oligocene
; Overdispersion
; Single-grains
; Subglacial landscape
; U-Th/He thermochronology
; Work-flows
; Erosion
; apatite
; Eocene-Oligocene boundary
; exhumation
; glacial erosion
; helium
; subglacial environment
; thermochronology
; uranium series dating
; Antarctic Ice Sheet
; Antarctica
; Beardmore Glacier
; East Antarctic Ice Sheet
; East Antarctica
; Transantarctic Mountains
英文摘要: Apatite (U-Th)/He thermochronology has the potential to reconstruct records of erosional exhumation that are critical to understanding interactions between climate, tectonics, and the cryosphere at high latitudes on million-year timescales. However this approach is often hindered by the problem of intrasample single-grain date dispersion. Here we present an extensive new apatite (U-Th)/He dataset (n = 361) from the central Transantarctic Mountains of East Antarctica between 160°E to 170°W and 84 to 86°S, and show that apparently uninterpretable data in most samples are a reflection of inadequate sampling of skewed date distributions. We outline a workflow for interpreting such dispersed data and demonstrate that geologically meaningful age interpretations are possible in the case of rapidly cooled samples, despite the wide array of potential causes for date dispersion. We show that for samples and compilations with a large number of single-grain analyses (n > ∼25), the youngest probability distribution peak represents the most likely time of fast cooling through the apatite (U-Th)/He closure temperature. When fewer grains are analyzed, the youngest peak is represented best by the minimum date or first quartile date, depending on sample size. Using this workflow, we show that since the latest Eocene, up to 8.8 km of exhumation occurred to incise the deepest point of the Beardmore Glacier trough. Rapid incision began at c. 37-34 Ma (at the latest by 34±3 Ma), coinciding with or slightly preceding the initiation of Antarctic glaciation at the Eocene-Oligocene transition, and contributed to at least 2.6 km of exhumation within the first 3-6 million years, at an apparent exhumation rate of no less than 0.4 mm/a. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165503
Appears in Collections: 气候变化与战略
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作者单位: Department of Geosciences, University of Arizona, Tucson, AZ 85721, United States; Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, United States; Department of Earth Sciences, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, United States
Recommended Citation:
He J.,Thomson S.N.,Reiners P.W.,et al. Rapid erosion of the central Transantarctic Mountains at the Eocene-Oligocene transition: Evidence from skewed (U-Th)/He date distributions near Beardmore Glacier[J]. Earth and Planetary Science Letters,2021-01-01,567