Arid
DOI10.1016/j.lithos.2016.01.001
P-T path and timing of crustal thickening during amalgamation of East and West Gondwana: A case study from the Hafafit Metamorphic Complex, Eastern Desert of Egypt
Abu El-Enen, Mahrous M.1; Abu-Alam, Tamer S.2,6; Whitehouse, Martin J.3; Ali, Kamal A.4; Okrusch, Martin5
通讯作者Abu El-Enen, Mahrous M.
来源期刊LITHOS
ISSN0024-4937
EISSN1872-6143
出版年2016
卷号263页码:213-238
英文摘要

The southeastern sector of the Hafafit Metamorphic Complex, southern Eastern Desert of Egypt comprises infrastructural orthogneisses of tonalite and syenogranite parentage, amphibolites, and a volcano-sedimentary association. These are overthrust by an obducted suprastructural ophiolite nappes via the Nugrus thrust. The protolith of the biotite-hornblende-gneisses was formed during island-arc accretion, while that of the garnet-biotite gneisses were formed in a within-plate regime, consistent with a transition to a post-collisional setting. The volcano-sedimentary association comprises interbedded and intercalated highly foliated metapelitic schists, metabasites, and leucocratic gneisses, deposited in a back-arc basin. The metapelites and the leucocratic gneisses originated from immature Fe-shales and arkoses derived from intermediate-mafic and acidic igneous rocks, respectively, via weak chemical weathering in a tectonically active island arc terrane. The intercalated amphibolites were derived from tholeiitic basalts generated in a back-arc setting.


The volcano-sedimentary association was metamorphosed under upper-amphibolite fades conditions with pressures of 9-13 kbar and temperatures of 570-675 degrees C, as derived from conventional geothermobarometry and pseudosection calculation. A steep, tight clockwise P-T path is constrained and a geothermal gradient around 20 degrees C/km is estimated for the peak metamorphism. We assume that deformation and metamorphism are due to crustal thickening during the collision of East and West Gondwana, where peak metamorphism took place in the middle to lower crust at 33 km average crustal depth. This was followed by a subsequent quasi-isothermal decompression due to rapid exhumation during wrench tectonics. Sinistral transcurrent shearing with extensional denudation resulted in vertical ductile thinning that was accompanied by heat input from magmatism, as indicated by a higher geothermal gradient during retrograde metamorphism and exhumation of the complex.


U-Pb data from magmatic zircons yields protolith ages of 731 +/- 3 Ma for the biotite-hornblende gneisses and 646 +/- 12 Ma for the garnet-biotite gneisses. Conforming to field evidence, our geochronology data point to a depositional age of the volcano-sedimentary cover at around 650 Ma. The age of metamorphism is constrained by a low Th/U ratio of a zircon grain crystallized at an age of 597 +/- 6 Ma. (C) 2016 Elsevier B.V. All rights reserved.


英文关键词Eastern Desert Volcano-sedimentary association Gondwana continental collision U Pb zircon age dating Clockwise P-T path
类型Article
语种英语
国家Egypt ; Sweden ; Saudi Arabia ; Germany ; Norway
收录类别SCI-E
WOS记录号WOS:000385325200013
WOS关键词TECTONIC SETTING DISCRIMINATION ; ARABIAN-NUBIAN SHIELD ; SR-ND ISOTOPES ; CORE COMPLEX ; TRACE-ELEMENT ; CHEMICAL CLASSIFICATION ; REGIONAL METAMORPHISM ; EMPIRICAL CALIBRATION ; SEDIMENTARY-ROCKS ; MIXING PROPERTIES
WOS类目Geochemistry & Geophysics ; Mineralogy
WOS研究方向Geochemistry & Geophysics ; Mineralogy
资源类型期刊论文
条目标识符http://119.78.100.177/qdio/handle/2XILL650/194979
作者单位1.Mansoura Univ, Fac Sci, Dept Geol, Mansoura 35516, Egypt;
2.Tanta Univ, Fac Sci, Dept Geol, Tanta, Egypt;
3.Swedish Museum Nat Hist, Dept Geosci, Box 50007, SE-10405 Stockholm, Sweden;
4.King Abdulaziz Univ, Fac Earth Sci, Dept Mineral Resources & Rocks, POB 80206, Jeddah 21589, Saudi Arabia;
5.Inst Geog & Geol, Hubland, D-97074 Wurzburg, Germany;
6.Norwegian Polar Res Inst, Tromso, Norway
推荐引用方式
GB/T 7714
Abu El-Enen, Mahrous M.,Abu-Alam, Tamer S.,Whitehouse, Martin J.,et al. P-T path and timing of crustal thickening during amalgamation of East and West Gondwana: A case study from the Hafafit Metamorphic Complex, Eastern Desert of Egypt[J],2016,263:213-238.
APA Abu El-Enen, Mahrous M.,Abu-Alam, Tamer S.,Whitehouse, Martin J.,Ali, Kamal A.,&Okrusch, Martin.(2016).P-T path and timing of crustal thickening during amalgamation of East and West Gondwana: A case study from the Hafafit Metamorphic Complex, Eastern Desert of Egypt.LITHOS,263,213-238.
MLA Abu El-Enen, Mahrous M.,et al."P-T path and timing of crustal thickening during amalgamation of East and West Gondwana: A case study from the Hafafit Metamorphic Complex, Eastern Desert of Egypt".LITHOS 263(2016):213-238.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[Abu El-Enen, Mahrous M.]的文章
[Abu-Alam, Tamer S.]的文章
[Whitehouse, Martin J.]的文章
百度学术
百度学术中相似的文章
[Abu El-Enen, Mahrous M.]的文章
[Abu-Alam, Tamer S.]的文章
[Whitehouse, Martin J.]的文章
必应学术
必应学术中相似的文章
[Abu El-Enen, Mahrous M.]的文章
[Abu-Alam, Tamer S.]的文章
[Whitehouse, Martin J.]的文章
相关权益政策
暂无数据
收藏/分享

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。