Tectonics of the Qinling (Central China): tectonostratigraphy, geochronology, and deformation history
Tectonics of the Qinling (Central China): tectonostratigraphy, geochronology, and deformation history
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DOI：
10.1016/s0040-1951(03)00053-2
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发表时间：
2003-05
期刊：
影响因子：
2.9
通讯作者：
L. Ratschbacher;B. Hacker;A. Calvert;L. Webb;J. Grimmer;M. Mcwilliams;T. Ireland;S. Dong;
中科院分区：
文献类型：
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作者：
L. Ratschbacher;B. Hacker;A. Calvert;L. Webb;J. Grimmer;M. Mcwilliams;T. Ireland;S. Dong;
秦岭造山带保存了中国中部中元古代晚期至新生代构造活动的记录。高压变质作用和蛇绿岩侵位（松树沟蛇绿岩）组装的扬子克拉通，包括下秦岭单元，Rodinia在1.0 Ga Grenvillian orthotransmittance。下秦岭单元于10.7Ga从扬子克拉通中裂陷出来。随后在470-490 Ma形成洋内弧，下秦岭单元首先增生到洋内弧，然后增生到中朝克拉通。俯冲作用在北方刘岭单元以北的所有单元上留下了大约400 Ma的安第斯型岩浆弧。斜向俯冲作用产生了志留-泥盆纪的WNW向左旋扭冲带（例如，晚二叠世-早三叠世的俯冲作用使它们在右行走压作用中重新活化（洛南、商襄、商丹），并使扬子克拉通北方边缘俯冲。武当变质核杂岩是在230-235 Ma以剪切伸展为主的地壳伸展过程中，由变质核边缘折返形成的。碰撞后向南缩短持续到侏罗纪早期。秦岭造山带在白垩纪的复活始于NW-SE向的左行张扭，与早白垩世大规模的地壳伸展和北方大别山的左行张扭同步，可能是西伯利亚-蒙古-中朝、拉萨-西缅-羌塘-印支碰撞和太平洋俯冲共同作用的结果。区域性右旋扭动在1060 ~ 100 Ma的NE-SW向伸展体制中较为活跃。早白垩世安第斯型大陆岩浆弧，具有广泛的早白垩世岩浆活动和弧后拉张作用，与扬子-印支陆块和西菲律宾陆块的碰撞有关，被缩短叠加。与始新世半地堑盆地有关的走滑断层和正断层记录了古近纪NNE-SSW向收缩和WNW-ESE向伸展。新近纪（？）以正断层和北北东向近水平伸展为特征。更新世（？）- 第四纪NW-SE伸展和NE-SW收缩包括左旋走滑断层，是印度-亚洲碰撞造成的横跨东亚的NW-SE伸展的一部分。
The Qinling orogen preserves a record of late mid-Proterozoic to Cenozoic tectonism in central China. High-pressure metamorphism and ophiolite emplacement (Songshugou ophiolite) assembled the Yangtze craton, including the lower Qinling unit, into Rodinia during the ∼1.0 Ga Grenvillian orogeny. The lower Qinling unit then rifted from the Yangtze craton at ∼0.7 Ga. Subsequent intra-oceanic arc formation at ∼470–490 Ma was followed by accretion of the lower Qinling unit first to the intra-oceanic arc and then to the Sino-Korea craton. Subduction then imprinted a ∼400 Ma Andean-type magmatic arc onto all units north of the northern Liuling unit. Oblique subduction created Silurian–Devonian WNW-trending, sinistral transpressive wrench zones (e.g., Lo-Nan, Shang-Dan), and Late Permian–Early Triassic subduction reactivated them in dextral transpression (Lo-Nan, Shang-Xiang, Shang-Dan) and subducted the northern edge of the Yangtze craton. Exhumation of the cratonal edge formed the Wudang metamorphic core complex during dominantly pure shear crustal extension at ∼230–235 Ma. Post-collisional south-directed shortening continued through the Early Jurassic. Cretaceous reactivation of the Qinling orogen started with NW–SE sinistral transtension, coeval with large-scale Early Cretaceous crustal extension and sinistral transtension in the northern Dabie Shan; it presumably resulted from the combined effects of the Siberia–Mongolia—Sino-Korean and Lhasa–West Burma—Qiangtang–Indochina collisions and Pacific subduction. Regional dextral wrenching was active within a NE–SW extensional regime between ∼60 and 100 Ma. An Early Cretaceous Andean-type continental magmatic arc, with widespread Early Cretaceous magmatism and back-arc extension, was overprinted by shortening related to the collision of Yangtze–Indochina Block with the West Philippines Block. Strike–slip and normal faults associated with Eocene half-graben basins record Paleogene NNE–SSW contraction and WNW–ESE extension. The Neogene(?) is characterized by normal faults and NNE-trending sub-horizontal extension. Pleistocene(?)–Quaternary NW–SE extension and NE–SW contraction comprises sinistral strike–slip faults and is part of the NW–SE extension imposed across eastern Asia by the India–Asia collision.