DOI: 10.1007/s00531-014-1106-6
Scopus记录号: 2-s2.0-84925497240
论文题名: Structural evidence for slip partitioning and inclined dextral transpression along the SE Sanandaj–Sirjan zone, Iran
作者: Shafiei Bafti S. ; Mohajjel M.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2015
卷: 104, 期: 3 起始页码: 587
结束页码: 601
语种: 英语
英文关键词: Inclined dextral transpression
; Khabr area
; SE Iran
; SE Sanandaj–Sirjan zone
英文摘要: The structural evolution of the Sanandaj–Sirjan zone is the result of the convergence of the Iranian microcontinent and the Afro-Arabian continent. The study area at Khabr in the SE Sanandaj–Sirjan zone, in the hinterland of the Zagros orogen, consists of Paleozoic, Mesozoic and Cenozoic rocks. In this area, deformation phases were distinguished in different rock units based on structural and stratigraphical evidence, and the deformational events are divided into two stages: (1) a Late Triassic event and (2) a Late Cretaceous to Miocene event. The Late Triassic deformation event caused regional metamorphism in the Paleozoic units. These units are overlain by unmetamorphosed Jurassic clastic sequences. Fabrics and structural evidence confirm that the F1 folding recumbent and refolded folds were synchronous with the metamorphism of the Paleozoic units and terminated in the Early Jurassic. The time table of the orogenic phases shows that this deformation event is related to the Cimmerian orogenic phase. From a geodynamic point of view, the early Cimmerian deformation in the southeastern Iranian margin suggests that the SE Sanandaj–Sirjan zone was an active margin at that time. The early Cimmerian discordance recorded the onset of a contractional component related to the oblique subduction of Neo-Tethys beneath the central Iranian microcontinent. Structures related to the Late Cretaceous to Miocene deformation phase are observed in Jurassic to Oligocene units, which contain moderately inclined and plunging folds. Comparing these folds with domains of deformation generated in models of transpression shows that the folding was caused by a combination of contractional and dip-slip components of movement, eventually resulting in the formation of a thrust system. The Khabr thrust systems consist of five sheets of oblique thrusts, duplex structures and shear zones. The shear zones generally strike E–W and dip moderately N (30°–40°). The occurrence of asymmetric folds with hinges that are either parallel to strike or plunge down dip demonstrates an oblique-slip component in these thrust shear zones. The stretching lineation in the mylonites within the shear zones is defined by the long axes of ellipsoidal grains of quartz, calcite, plagioclase and garnet. In general, stretching lineations trend from N40°W to N80°W with an intermediate (35°) plunge. The geometry of foliation and lineation within these shear zones shows the effect of dip- and oblique-slip shearing. Deformation continued with strike-slip faulting becoming important during the last stages of deformation from the Miocene to the present day. The results of this study demonstrate that the evolution of the SE Sanandaj–Sirjan zone, from Late Triassic to Miocene, is compatible with an inclined dextral transpression along this zone. © 2014, Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925497240&doi=10.1007%2fs00531-014-1106-6&partnerID=40&md5=056765bb501c042d3d07804d64defc33
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70315
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 Geology, Shahid Bahonar University of Kerman, Kerman, Iran; Department of Geology, University of Tarbiat Modarres, Tehran, Iran
Recommended Citation:
Shafiei Bafti S.,Mohajjel M.. Structural evidence for slip partitioning and inclined dextral transpression along the SE Sanandaj–Sirjan zone, Iran[J]. International Journal of Earth Sciences,2015-01-01,104(3)