气候变化领域集成服务门户(CCPortal): Rapid erosion of the central Transantarctic Mountains at the Eocene-Oligocene transition: Evidence from skewed (U-Th)/He date distributions near Beardmore Glacier

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DOI	10.1016/j.epsl.2021.117009
	Rapid erosion of the central Transantarctic Mountains at the Eocene-Oligocene transition: Evidence from skewed (U-Th)/He date distributions near Beardmore Glacier
	He J.; Thomson S.N.; Reiners P.W.; Hemming S.R.; Licht K.J.
发表日期	2021
ISSN	0012821X
卷号	567
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.
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
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203125
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
推荐引用方式 GB/T 7714	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],2021,567.
APA	He J.,Thomson S.N.,Reiners P.W.,Hemming S.R.,&Licht K.J..(2021).Rapid erosion of the central Transantarctic Mountains at the Eocene-Oligocene transition: Evidence from skewed (U-Th)/He date distributions near Beardmore Glacier.Earth and Planetary Science Letters,567.
MLA	He J.,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".Earth and Planetary Science Letters 567(2021).