DOI: 10.1016/j.epsl.2019.115929
论文题名: Sediment size and abrasion biases in detrital thermochronology
作者: Lukens C.E. ; Riebe C.S. ; Sklar L.S. ; Shuster D.L.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 531 语种: 英语
中文关键词: (U-Th)/He dating
; cosmogenic nuclides
; geochronology
; Inyo Creek
; thermochronometry
; U-Pb dating
英文关键词: Abrasion
; Binary alloys
; Catchments
; Erosion
; Geochronology
; Indium alloys
; Lead alloys
; Runoff
; Sand
; Tectonics
; Uranium alloys
; (U-Th)/He dating
; Cosmogenic nuclides
; Inyo Creek
; Thermochronometry
; U-Pb dating
; Sediments
英文摘要: Detrital thermochronology has revolutionized the study of sediment provenance at orogen scales and spatial patterns in erosion at catchment scales. A strength of the method is that a handful of stream sand can be used to represent processes over landscape scales. However, it relies on both the widely recognized assumption that sand is supplied from every part of the catchment, and the implicit assumption that the fraction of eroded material that is sand-sized does not change across the landscape. These assumptions may be violated when the catchment contains spatial variations in the initial sizes of sediment produced by hillslope weathering or when abrasion during transport causes size reduction of sediment sourced from distal parts of the catchment. In either case, a detrital sample spanning a narrow range of sediment sizes (e.g., sand) may fail to represent the catchment as a whole, leading to bias in thermochronology of erosional and tectonic processes. We used forward modeling to quantify biases that can arise due to plausible abrasion rates and spatial variations in initial sediment size. Our results reveal significant reductions in the chance of detecting age populations originating from the highest, most distal parts of the landscape, leading to potentially erroneous interpretations in provenance studies. In tracer thermochronology, the biases distort detrital age distributions, leading to potentially profound misinterpretation of spatial patterns in erosion rates. Our analysis shows that the sediment size and abrasion biases increase with catchment area and relief but can be significant in small catchments (<10km2) with moderate relief (>0.5 km). We show that the biases can be mitigated by analyzing a sufficient number of grains in multiple sediment size classes. © 2019 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165140
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071, United States; Department of Geography, Victoria University of Wellington, Wellington, 6140, New Zealand; Department of Earth and Climate Sciences, San Francisco State UniversityCA 94132, United States; Department of Geography, Planning, and Environment, Concordia University, Montreal, Quebec H3G 1M8, Canada; Department of Earth and Planetary Sciences, University of California, Berkeley, CA 94720, United States; Berkeley Geochronology Center, Berkeley, CA 94709, United States
Recommended Citation:
Lukens C.E.,Riebe C.S.,Sklar L.S.,et al. Sediment size and abrasion biases in detrital thermochronology[J]. Earth and Planetary Science Letters,2020-01-01,531