气候变化领域集成服务门户(CCPortal): A 100-m.y.-long window onto mass-flow processes in the Patagonian Mesozoic subduction zone (Diego de Almagro Island, Chile)

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DOI	10.1130/B31891.1
	A 100-m.y.-long window onto mass-flow processes in the Patagonian Mesozoic subduction zone (Diego de Almagro Island, Chile)
	Angiboust S.; Cambeses A.; Hyppolito T.; Glodny J.; Monié P.; Calderón M.; Juliani C.
发表日期	2018
ISSN	167606
起始页码	1439
结束页码	1456
卷号	130 期号:2021-09-10
英文摘要	Diego de Almagro Island was formed by the subduction and accretion of several seafloor- derived tectonic slices with very heterogeneous ages and pressure-temperature-time (P-T-t) paths. The highest element of the pile (the Lazaro unit) evidences subduction in the high-P granulite field (~1.3 GPa, 750 °C) at ca. 163 Ma. Below it, a thin tectonic sliver (the Garnet Amphibolite unit) preserves eclogitefacies remnants (~570 °C and ~1.7 GPa) formed at ca. 131 Ma (in situ U-Pb zircon rim ages). Peak assemblages were nearly fully amphibolitized during decompression down to ~1.2 GPa and ~600 °C at 125-120 Ma (Rb-Sr multimineral dating). The underlying Blueschist unit has ~50 m.y. younger metamorphic ages and exhibits slightly cooler peak burial conditions (~520 °C, 1.7 GPa; ca. 80 Ma, in situ white mica Ar-Ar ages and multimineral Rb-Sr dating) and is devoid of amphibolitization. The mylonites from the sinistral strike-slip Seno Arcabuz shear zone bounding Diego de Almagro Island to the east also exhibit amphibolite-facies (~620 °C and ~0.9 GPa) deformation at ca. 117 Ma (multimineral Rb-Sr ages). In situ white mica Ar-Ar dating and multimineral Rb-Sr dating of low-T mylonites (~450 °C) along the base of the Lazaro unit reveal partial resetting of high-T assemblages during tectonic displacement between 115 and 72 Ma and exhumation of the slice stack. Detrital zircon U-Th-Pb ages indicate that the material accreted on Diego de Almagro Island has been mostly recycled from a Permian-Triassic accretionary wedge (Madre de Dios accretionary complex) exposed along the subduction buttress. Geological and geochronological constraints suggest that the rocks of the Seno Arcabuz shear zone and the Lazaro unit were tectonically eroded from the buttress, while the underlying Garnet Amphibolite and Blueschist units instead derive from the subducted oceanic basin, with increasingly younger maximum depositional ages. The very long residence time of the rocks (~90 m.y. for the Lazaro unit) along the hanging wall of the subduction interface recorded long-term cooling along the Patagonian subduction zone during the Mesozoic. Diego de Almagro Island therefore represents a unique window onto long-term tectonic processes such as subduction interface down-stepping, tectonic erosion, and episodic underplating near the base of an accretionary wedge (40-50 km). © 2018 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185093
作者单位	Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, Centre National de la Recherche Scientifique (CNRS), Paris, F-75005, France; Department of Mineralogy and Petrology, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, Granada, 18002, Spain; Instituto de Geociências, Universidade de São Paulo, Rua do Lago, 562, São Paulo, 05505-080, Brazil; German Research Centre for Geosciences (GFZ), Potsdam, 14473, Germany; Géosciences Montpellier UMR-CNRS 5243, Place E. Bataillon, Montpellier, 34090, France; Carrera de Geología, Universidad Andres Bello, Sazie 2119, Santiago, Chile
推荐引用方式 GB/T 7714	Angiboust S.,Cambeses A.,Hyppolito T.,et al. A 100-m.y.-long window onto mass-flow processes in the Patagonian Mesozoic subduction zone (Diego de Almagro Island, Chile)[J],2018,130(2021-09-10).
APA	Angiboust S..,Cambeses A..,Hyppolito T..,Glodny J..,Monié P..,...&Juliani C..(2018).A 100-m.y.-long window onto mass-flow processes in the Patagonian Mesozoic subduction zone (Diego de Almagro Island, Chile).Bulletin of the Geological Society of America,130(2021-09-10).
MLA	Angiboust S.,et al."A 100-m.y.-long window onto mass-flow processes in the Patagonian Mesozoic subduction zone (Diego de Almagro Island, Chile)".Bulletin of the Geological Society of America 130.2021-09-10(2018).