气候变化领域集成服务门户(CCPortal): Dating fault damage along the eastern Denali fault zone with hematite (U-Th)/He thermochronometry

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DOI	10.1016/j.epsl.2021.116872
	Dating fault damage along the eastern Denali fault zone with hematite (U-Th)/He thermochronometry
	McDermott R.G.; Ault A.K.; Caine J.S.
发表日期	2021
ISSN	0012821X
卷号	563
英文摘要	Unraveling complex slip histories in fault damage zones to understand relations among deformation, hydrothermal alteration, and surface uplift remains a challenge. The dextral eastern Denali fault zone (EDFZ; southwest Yukon, Canada) bounds the Kluane Ranges and hosts a variety of fault-related rocks, including hematite fault surfaces, which have been exhumed through the brittle regime over a protracted period of geologic time. Scanning electron microscopy-based microtextural observations and hematite (U-Th)/He (hematite He) thermochronometry from these surfaces indicate multiple generations of foliated, high-aspect ratio hematite plates. Single-aliquot hematite He dates (n=38) from 11 samples range from 11.5 ± 3.2 Ma (2σ) to 3.4 ± 2.1 Ma and exhibit moderate inter- and intrasample dispersion. A subset of dates is 15-20 Myr younger than previously published apatite (U-Th)/He dates from collocated host rocks, despite similar closure temperatures, precluding a simple ambient cooling interpretation for our hematite He data. Mixture modeling defines hematite He date populations at ∼8 Ma, ∼6 Ma, and ∼4 Ma, and when combined with microtextural observations, supports episodes of hydrothermal alteration and fault reactivation at aseismic to subseismic slip rates. There is no evidence that hematite experienced deformation- or hydrothermal fluid-related He loss. Hematite He dates overlap previously documented Kluane Ranges surface uplift and shifting dynamics of the Yakutat microplate, pinpointing fault networks and deformation processes that accommodate regional deformation in response to far-field plate boundary processes. © 2021
关键词	aseismic slip Denali fault hematite (U-Th)/He thermochronometry hematite microtextures surface uplift
英文关键词	Aspect ratio; Clay alteration; Deformation; Earthquakes; Fault slips; Phosphate minerals; Population statistics; Scanning electron microscopy; Strike-slip faults; Aseismic slip; Denali fault; Denali fault zone; Fault damage zone; Haematite; Hematite (U-th)/he thermochronometry; Hematite microtexture; Hydrothermal alterations; Surface uplift; Thermochronometry; Hematite; deformation; fault zone; hematite; plate boundary; slip; texture; thermochronology; uplift; uranium series dating; Alaska; Denali Fault Zone; United States
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/203219
作者单位	U.S. Geological Survey, Anchorage, AK, United States; Department of Geosciences, Utah State University, Logan, UT, United States; U.S. Geological Survey, Denver, CO, United States
推荐引用方式 GB/T 7714	McDermott R.G.,Ault A.K.,Caine J.S.. Dating fault damage along the eastern Denali fault zone with hematite (U-Th)/He thermochronometry[J],2021,563.
APA	McDermott R.G.,Ault A.K.,&Caine J.S..(2021).Dating fault damage along the eastern Denali fault zone with hematite (U-Th)/He thermochronometry.Earth and Planetary Science Letters,563.
MLA	McDermott R.G.,et al."Dating fault damage along the eastern Denali fault zone with hematite (U-Th)/He thermochronometry".Earth and Planetary Science Letters 563(2021).