Metamorphic stages in mountain belts during a Wilson cycle: A case study in the central Sanandaj-Sirjan zone (Zagros Mountains, Iran)
文献类型:期刊论文
作者 | Shakerardakani, Farzaneh1,2,3; Neubauer, Franz1; Bernroider, Manfred1; Finger, Fritz4; Hauzenberger, Christoph5; Genser, Johann1; Waitzinger, Michael4; Monfaredi, Behzad5 |
刊名 | GEOSCIENCE FRONTIERS
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出版日期 | 2022-03-01 |
卷号 | 13期号:2页码:30 |
关键词 | Carboniferous Polyphase metamorphism Petrochronology Chemical Th-U-Pb age dating Ar-40/Ar-39 dating Collisional orogen |
ISSN号 | 1674-9871 |
DOI | 10.1016/j.gsf.2021.101272 |
英文摘要 | Polymetamorphic units are important constituents of continent-continent collisional orogens, and rift metamorphic assemblages are often overprinted by subsequent metamorphism during subduction and collision. This study reports the metamorphic conditions and evolution of the Dorud-Azna metamorphic units in the central part of the Sanandaj-Sirjan zone (SSZ), Iran. Here, new geothermobarometry results are integrated with Ar-40/Ar-39 mineral and Th-U-Pb monazite and thorite ages to provide new insight of polyphase metamorphism in the two different basement units of the SSZ, the lower Galeh-Doz orthogneiss and higher Amphibolite-Metagabbro units. In the Amphibolite-Metagabbro unit, staurolite micaschist underwent a prograde P-T evolution from 640 +/- 20 degrees C/6.2 +/- 0.8 kbar in garnet cores (M1) to 680 +/- 20 degrees C/7.2 +/- 1.0 kbar in garnet rims (M2). Three Th-U-Pb monazite ages of 306 +/- 5 Ma, 322 +/- 28 Ma and 336 +/- 39 Ma from the garnet-micaschists testify the Carboniferous age of M1 metamorphism. In the same unit, the metagabbro records P-T conditions of 4.0 +/- 0.8 kbar and 580 +/- 50 degrees C in the (magmatic) amphibole core (Late Carboniferous intrusion) to 7.5 +/- 0.7 kbar and 700 +/- 20 degrees C in the amphibole rim indicating a prograde P-T path during subsequent burial (M1). New (40) Ar/Ar-39 dating of white mica from the staurolite micaschist yielded a staircase pattern ranging from 36 +/- 12 Ma to 170 +/- 2 Ma. This implies polymetamorphism with a minimum Late Jurassic cooling age through the Ar retention temperature of ca. 425 +/- 25 degrees C after M2 metamorphism and a Paleogene low-grade metamorphic overprint (M3), while Ar-40/Ar-39 white mica dating of garnet micaschist yielded a plateau age of 137.84 +/- 0.65 Ma. We therefore interpret the amphibolite-grade metamorphism M2 to have predated 170 Ma and is likely between 180 and 200 Ma. Furthermore, it is overprinted at about 36 Ma under retrogressive low-grade M3 metamorphism (at temperatures of -350-240 degrees C) during final shortening and exhumation. In the underlying Galeh-Doz unit, the Panafrican granitic orthogneiss intruded at P-T conditions of 3.2 +/- 4 kbar and 700 +/- 20 degrees C, then it was metamorphosed and deformed at 600 +/- 50 degrees C and 2.0 +/- 0.8 kbar (metamorphic stage Ml) prior to Late Carboniferous intrusion of mafic dikes. Ar-40/Ar-39 dating of amphibole from the Galeh-Doz orthogneiss gave plateau-like steps between 260 and 270 Ma, representing the age of cooling through ca. 500 degrees C after the Ml metamorphic event. Interestingly, the results of this study demonstrate polyphase metamorphic histories in both the Galeh-Doz orthogneiss and Amphibolite-Metagabbro units at different P-T conditions and final thickskinned Paleogene emplacement of these units over the underlying low-grade metamorphic June Complex. Our findings suggest that both units are affected by high-Tflow-P Late Carboniferous orogenic metamorphism along with the bimodal magmatism, as result of rifting. We propose that the Early Jurassic amphibolite-grade M2 metamorphism of the SSZ is correlated with the initial subduction of the Neotethyan Ocean. Eventually, the investigated units reflect various stages of a Wilson cycle, from rifting to initiation of the subduction in final plate collision. (C) 2021 China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. |
WOS关键词 | PETROLOGICAL ELEMENTARY TOOLS ; CANYON SANIDINE STANDARD ; AL2SIO5 TRIPLE POINT ; K-40 DECAY CONSTANTS ; NW IRAN ; TECTONIC EVOLUTION ; WESTERN IRAN ; MONAZITE GEOCHRONOLOGY ; CONTINENTAL COLLISION ; JOINT DETERMINATION |
资助项目 | Afro-Asiatisches Institut, Salzburg |
WOS研究方向 | Geology |
语种 | 英语 |
WOS记录号 | WOS:000773521400006 |
出版者 | CHINA UNIV GEOSCIENCES, BEIJING |
资助机构 | Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg ; Afro-Asiatisches Institut, Salzburg |
源URL | [http://ir.iggcas.ac.cn/handle/132A11/105039] ![]() |
专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
通讯作者 | Shakerardakani, Farzaneh |
作者单位 | 1.Paris Lodron Univ Salzburg, Dept Geog & Geol, Hellbrunner Str 34, A-5020 Salzburg, Austria 2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 3.Chinese Acad Sci, Innovat Acad Earth Sci, Beijing 100029, Peoples R China 4.Paris Lodron Univ Salzburg, Dept Chem & Phys Mat, Jakob Haringer Str 2a, A-5020 Salzburg, Austria 5.Karl Franzens Univ Graz, Inst Earth Sci, NAWI Graz Geoctr, Univ Pl 2, A-8010 Graz, Austria |
推荐引用方式 GB/T 7714 | Shakerardakani, Farzaneh,Neubauer, Franz,Bernroider, Manfred,et al. Metamorphic stages in mountain belts during a Wilson cycle: A case study in the central Sanandaj-Sirjan zone (Zagros Mountains, Iran)[J]. GEOSCIENCE FRONTIERS,2022,13(2):30. |
APA | Shakerardakani, Farzaneh.,Neubauer, Franz.,Bernroider, Manfred.,Finger, Fritz.,Hauzenberger, Christoph.,...&Monfaredi, Behzad.(2022).Metamorphic stages in mountain belts during a Wilson cycle: A case study in the central Sanandaj-Sirjan zone (Zagros Mountains, Iran).GEOSCIENCE FRONTIERS,13(2),30. |
MLA | Shakerardakani, Farzaneh,et al."Metamorphic stages in mountain belts during a Wilson cycle: A case study in the central Sanandaj-Sirjan zone (Zagros Mountains, Iran)".GEOSCIENCE FRONTIERS 13.2(2022):30. |
入库方式: OAI收割
来源:地质与地球物理研究所
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