气候变化领域集成服务门户(CCPortal): Deformation within the Cycladic subduction–exhumation channel: new insights from the enigmatic Makrotantalo nappe (Andros; Aegean)

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DOI	10.1007/s00531-019-01680-3
	Deformation within the Cycladic subduction–exhumation channel: new insights from the enigmatic Makrotantalo nappe (Andros; Aegean)
	Gerogiannis N.; Xypolias P.; Chatzaras V.; Aravadinou E.; Papapavlou K.
发表日期	2019
ISSN	14373254
起始页码	817
结束页码	843
卷号	108 期号:3
英文摘要	New detailed geological/structural mapping coupled with microstructural investigations and amphibole chemistry analyses are used to elucidate the enigmatic tectonic evolution of the Makrotantalo nappe on northern Andros (Aegean region). On the basis of the new geological map, we re-evaluate the structural position of samples with previously published metamorphic ages to show that the Makrotantalo nappe has been affected by the early Eocene high-pressure (HP) metamorphism. Therefore, the Makrotantalo nappe is an integral part of the Cycladic Blueschist Unit (CBU). The early, main ductile deformation phase recognized in the mapped area, is associated with the emplacement of the Makrotantalo nappe over the North Cyclades nappe at deep subduction levels during early Eocene. The subsequent deformation phase occurred at the middle Eocene–Oligocene synchronous with the decompression of blueschist rocks from the stability field of glaucophane to that of actinolite. During this phase, the nappe pile was folded by map-scale folds, which were locally transposed by ductile shear zones. These shear zones were related with NE-directed oblique thrusting and, locally, either restacked the nappe pile or reworked the early nappe contact. Our results in combination with previous studies in the northern Cyclades show that the top-to-the-NE shearing was dominant at a large part of the CBU during exhumation. Opposite, SW-directed shearing was restricted at the upper structural levels of the CBU. We suggest that the observed spatial variation in shear sense is compatible with NE- rather than SW-directed ductile extrusion of the CBU. © 2019, Geologische Vereinigung e.V. (GV).
英文关键词	Amphibole chemistry; Blueschists; Ductile deformation; Ductile extrusion; Hellenides; Quartz fabrics
语种	英语
scopus关键词	amphibole; blueschist; ductile deformation; exhumation; extrusion; nappe; quartz; subduction; tectonic evolution; Andros [Cyclades]; Cyclades; Greece; Hellenides; Southern Aegean
来源期刊	International Journal of Earth Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/147858
作者单位	Department of Geology, University of Patras, Patras, 26500, Greece; School of Geosciences, The University of Sydney, Sydney, NSW, Australia; GEOTOP, Université du Québec à Montréal, Montreal, H2X 3Y7, Canada
推荐引用方式 GB/T 7714	Gerogiannis N.,Xypolias P.,Chatzaras V.,等. Deformation within the Cycladic subduction–exhumation channel: new insights from the enigmatic Makrotantalo nappe (Andros; Aegean)[J],2019,108(3).
APA	Gerogiannis N.,Xypolias P.,Chatzaras V.,Aravadinou E.,&Papapavlou K..(2019).Deformation within the Cycladic subduction–exhumation channel: new insights from the enigmatic Makrotantalo nappe (Andros; Aegean).International Journal of Earth Sciences,108(3).
MLA	Gerogiannis N.,et al."Deformation within the Cycladic subduction–exhumation channel: new insights from the enigmatic Makrotantalo nappe (Andros; Aegean)".International Journal of Earth Sciences 108.3(2019).