Early Cretaceous Tectonics and Evolution of the Tibetan Plateau
Early Cretaceous Tectonics and Evolution of the Tibetan Plateau
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DOI：
10.1111/1755-6724.12728
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发表时间：
2016-06
期刊：
影响因子：
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通讯作者：
Wu Zhenhan;Z. Zhen;P. Barosh;Ye Peisheng
中科院分区：
文献类型：
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作者：
Wu Zhenhan;Z. Zhen;P. Barosh;Ye Peisheng
昆仑山-喜马拉雅山早白垩世地层、构造、岩浆岩和火山岩等地质资料，揭示了青藏高原早白垩世古构造及其动力学运动的新面貌。早白垩世，青藏地区存在两大古海洋，即羌塘地块与拉萨地块之间的中特提斯洋和拉萨地块与喜马拉雅地块之间的新特提斯洋。新特提斯洋南缘和北方形成喜马拉雅边缘海和拉萨南海，中特提斯洋南缘和北方形成藏中海和羌塘边缘海。早白垩世，一个海湾延伸到塔里木盆地西南部。早白垩世拉萨地块中部和北方发生强烈逆冲推覆、岩浆侵位和火山喷发，而藏北北方地区沿着可可西里和南昆仑断裂发生走滑活动。早白垩世构造和岩浆K2 O地球化学表明早白垩世中特提斯洋板块沿着班戈-怒江缝合带向南俯冲，该缝合带在晚白垩世-早新生代期间向南推覆了约87 km。喜马拉雅地块和拉萨地块南部在早白垩世没有发生强烈的逆冲推覆和岩浆侵位，表明扩张的新特提斯洋板块在早白垩世没有俯冲。在北部，早白垩世在可可西里、昆仑、祁连和塔里木东北部形成了红层陆相盆地，早白垩世晚期羌塘地块隆升后羌塘边缘海消失。
Selected geological data on Early Cretaceous strata, structures, magmatic plutons and volcanic rocks from the Kunlun to Himalaya Mountains reveal a new view of the Early Cretaceous paleo‐tectonics and the related geodynamic movement of the Tibetan Plateau. Two major paleo‐oceans, the Mid‐Tethys Ocean between the Qiangtang and Lhasa blocks, and the Neo‐Tethys Ocean between the Lhasa and Himalayan blocks, existed in the Tibetan region in the Early Cretaceous. The Himalayan Marginal and South Lhasa Seas formed in the southern and northern margins of the Neo‐Tethys Ocean, the Central Tibet Sea and the Qiangtang Marginal Sea formed in the southern and northern margins of the Mid‐Tethys Ocean, respectively. An arm of the sea extended into the southwestern Tarim basin in the Early Cretaceous. Early Cretaceous intensive thrusting, magmatic emplacement and volcanic eruptions occurred in the central and northern Lhasa Block, while strike‐slip formed along the Hoh‐Xil and South Kunlun Faults in the northern Tibetan region. Early Cretaceous tectonics together with magmatic K2O geochemistry indicate an Early Cretaceous southward subduction of the Mid‐Tethys Oceanic Plate along the Bangoin‐Nujiang Suture which was thrust ∼87 km southward during the Late Cretaceous‐Early Cenozoic. No intensive thrust and magmatic emplacement occurred in the Early Cretaceous in the Himalayan and southern Lhasa Blocks, indicating that the spreading Neo‐Tethys Oceanic Plate had not been subducted in the Early Cretaceous. To the north, terrestrial basins of red‐beds formed in the Hoh‐Xil, Kunlun, Qilian and the northeastern Tarim blocks in Early Cretaceous, and the Qiangtang Marginal Sea disappeared after the Qiangtang Block uplifted in the late Early Cretaceous.