Dating fault damage along the eastern Denali fault zone with hematite (U-Th)/He thermochronometry
نویسندگان
چکیده
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 zone (EDFZ; southwest Yukon, Canada) bounds the Kluane Ranges hosts variety of fault-related rocks, including hematite surfaces, which have been exhumed through brittle regime over protracted period geologic time. Scanning electron microscopy-based microtextural observations (U-Th)/He (hematite He) thermochronometry from these surfaces indicate multiple generations foliated, high-aspect ratio plates. Single-aliquot He dates (n=38) 11 samples range 11.5 ± 3.2 Ma (2?) 3.4 2.1 exhibit moderate inter- intrasample dispersion. A subset is 15-20 Myr younger than previously published apatite collocated host despite similar closure temperatures, precluding simple ambient cooling interpretation for our data. Mixture modeling defines date populations at ?8 Ma, ?6 ?4 when combined with observations, supports episodes alteration reactivation aseismic subseismic rates. There no evidence that experienced deformation- or fluid-related loss. Hematite overlap documented shifting dynamics Yakutat microplate, pinpointing networks deformation processes accommodate regional response far-field plate boundary processes.
منابع مشابه
Ten Kilometer Vertical Moho Offset and Shallow Velocity Contrast Along the Denali Fault Zone from Double-difference Tomography, Receiver Functions, and Fault Zone Head Waves
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ژورنال
عنوان ژورنال: Earth and Planetary Science Letters
سال: 2021
ISSN: ['1385-013X', '0012-821X']
DOI: https://doi.org/10.1016/j.epsl.2021.116872