DOI: 10.1007/s00531-013-0952-y
Scopus记录号: 2-s2.0-84893795221
论文题名: Polyphase tectonics and late Variscan extension in Austria (Moldanubian Zone, Strudengau area)
作者: Zeitlhofer H. ; Schneider D. ; Grasemann B. ; Petrakakis K. ; Thöni M.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2014
卷: 103, 期: 1 起始页码: 83
结束页码: 102
语种: 英语
英文关键词: Bohemian Massif
; Extension
; Low-temperature shear zones
; Lower crustal flow
; Variscan orogeny
Scopus关键词: amphibolite facies
; decompression
; deformation
; dike swarm
; extensional tectonics
; folding
; gneiss
; greenschist facies
; Hercynian orogeny
; lower crust
; mylonitization
; shear zone
; tectonic evolution
; Austria
; Bohemian Massif
英文摘要: New data suggest syn-convergent extrusion and polyphase tectonics followed by late Variscan extension in the Strudengau area of the southern Moldanubian zone in Austria. The tectonic history can be summarized as follows: (1) The oldest ductile event is observed in HT/LP metamorphic pelitic gneisses, which preserve E-dipping foliation planes (D1-fabric) with NW-SE-trending lineations. (2) The overlying gneisses record HT/HP conditions with decompression-induced anatexis in the central part of the domain. These gneisses exhibit N-S trending, horizontal lineations along steep-dipping foliation planes (D2-fabric) crosscutting the D1-fabric of the pelitic gneisses. Along the margin, these rocks have been strongly mylonitized under amphibolite facies conditions (D2). D2 is interpreted as a significant vertical shear zone, which juxtaposes the HT/LP rocks against the orogenic lower crust. (3) Lastly, the whole area is overprinted by localized shear zones (D3-fabric) with top-to-the-NW kinematics. This newly discovered Strudengau shearing event is associated with isoclinal folding that possesses axial planes parallel to the mylonitic foliation and fold axes parallel to the stretching lineations. Initial mylonitization occurred under greenschist facies, representing the latest ductile event of the Strudengau area. The new geochronological data presented here indicate a narrow time frame (c. 323-318 Ma) for the D3 deformation. Therefore, this event is contemporaneous with the intrusion of the granites of the South Bohemian Batholith (330-310 Ma). The nearby South Bohemian Batholith and generally steep dyke swarms in the Strudengau area and to the north trend in a NE-SW preferred orientation, interpreted to be D3-synkinematic magmatism. In a regional context, the NW-SE stretching during D3 together with the synkinematic intrusion of dykes is associated with late orogenic extension in the Austrian Moldanubian Zone. Kinematic data of brittle normal faults and tension gashes are consistent with NW-SE-oriented extension under cooler conditions. © 2013 Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893795221&doi=10.1007%2fs00531-013-0952-y&partnerID=40&md5=8a7a1b7e2461a5076589fe2bec589cce
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70457
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Geodynamics and Sedimentology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria; Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, K1N 6N5, Canada; Department of Lithospheric Research, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
Recommended Citation:
Zeitlhofer H.,Schneider D.,Grasemann B.,et al. Polyphase tectonics and late Variscan extension in Austria (Moldanubian Zone, Strudengau area)[J]. International Journal of Earth Sciences,2014-01-01,103(1)