干旱区生态环境知识资源中心(Arid): Late Oligocene-Early Miocene Detachment Faulting in Crystalline Basement, Mecca Hills, CA, Documented With Zircon (U-Th)/He Date-eU-Visual Radiation Damage Patterns

Arid

DOI	10.1029/2021TC006809
	Late Oligocene-Early Miocene Detachment Faulting in Crystalline Basement, Mecca Hills, CA, Documented With Zircon (U-Th)/He Date-eU-Visual Radiation Damage Patterns
	Moser, A. C.; Ault, A. K.; Stearns, M. A.; Evans, J. P.; Guenthner, W. R.
通讯作者	Moser, AC (corresponding author), Utah State Univ, Dept Geosci, Logan, UT 84322 USA. ; Moser, AC (corresponding author), Univ Calif Santa Barbara, Dept Earth Sci, Santa Barbara, CA 93106 USA.
来源期刊	TECTONICS
ISSN	0278-7407
EISSN	1944-9194
出版年	2021
卷号	40 期号:9
英文摘要	Zircon (U-Th)/He (zircon He) thermochronometry and visual radiation damage relationships reveal the timing and patterns of Orocopia Schist and North American basement exhumation in the Mecca Hills, CA. Zircon crystals from these units were selected to maximize the spectrum in visual metamictization and effective U (eU) concentrations, and thus He retentivity, in each sample. Zircon He dates (n = 31 analyses) from six of seven samples are similar to 24 Ma regardless of eU, despite a large spread in eU (>2,800 ppm) across all grains. One sample (n = 7 analyses) yields a mean similar to 65 Ma date. Uniform zircon He dates over a range of eU concentrations and their preserved visual metamictization indicate these grains experienced a thermal history that induced complete He loss, but did not anneal the damage. This is consistent with recent work that indicates zircon radiation damage anneals at higher temperatures than parameterized in current damage annealing models. The zircon He data patterns, together with new zircon U-Pb results and thermal history modeling, reveal the two basement units in the Mecca Hills exhumed simultaneously at similar to 24 Ma, likely by the Orocopia Mountains detachment fault. This requires both basement units lie in the footwall of the detachment, and implies the breakaway zone of the Orocopia Mountains detachment fault was west of the present-day Mecca Hills basement exposures and has been translated by the San Andreas fault. Combined with prior work, our data suggest large-magnitude late Oligocene-early Miocene extension in the southwestern Cordillera was more widespread than previously recognized.
英文关键词	zircon (U-Th) He thermochronometry radiation damage Mecca Hills Orocopia Schist Orocopia Mountains detachment fault
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000702387900007
WOS关键词	SAN-ANDREAS FAULT ; LOW-TEMPERATURE THERMOCHRONOLOGY ; CENOZOIC TECTONIC EVOLUTION ; MOJAVE DESERT REGION ; SOUTHERN CALIFORNIA ; APATITE (U-TH)/HE ; FISSION-TRACK ; OROCOPIA SCHIST ; NATURAL ZIRCON ; SOUTHWESTERN ARIZONA
WOS类目	Geochemistry & Geophysics
WOS研究方向	Geochemistry & Geophysics
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/364778
作者单位	[Moser, A. C.; Ault, A. K.; Evans, J. P.] Utah State Univ, Dept Geosci, Logan, UT 84322 USA; [Moser, A. C.] Univ Calif Santa Barbara, Dept Earth Sci, Santa Barbara, CA 93106 USA; [Stearns, M. A.] Utah Valley Univ, Dept Earth Sci, Orem, UT USA; [Guenthner, W. R.] Univ Illinois, Dept Geol, Urbana, IL USA
推荐引用方式 GB/T 7714	Moser, A. C.,Ault, A. K.,Stearns, M. A.,et al. Late Oligocene-Early Miocene Detachment Faulting in Crystalline Basement, Mecca Hills, CA, Documented With Zircon (U-Th)/He Date-eU-Visual Radiation Damage Patterns[J],2021,40(9).
APA	Moser, A. C.,Ault, A. K.,Stearns, M. A.,Evans, J. P.,&Guenthner, W. R..(2021).Late Oligocene-Early Miocene Detachment Faulting in Crystalline Basement, Mecca Hills, CA, Documented With Zircon (U-Th)/He Date-eU-Visual Radiation Damage Patterns.TECTONICS,40(9).
MLA	Moser, A. C.,et al."Late Oligocene-Early Miocene Detachment Faulting in Crystalline Basement, Mecca Hills, CA, Documented With Zircon (U-Th)/He Date-eU-Visual Radiation Damage Patterns".TECTONICS 40.9(2021).