Prototethyan orogenesis in southwest Yunnan and Southeast Asia
Prototethyan orogenesis in southwest Yunnan and Southeast Asia
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DOI：
10.1007/s11430-021-9958-7
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发表时间：
2022-08
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影响因子：
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通讯作者：
Yuejun Wang;Xianghong Lu;Xin Qian;Sainan Wu;Yuzhi Zhang;Yang Wang
中科院分区：
文献类型：
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作者：
Yuejun Wang;Xianghong Lu;Xin Qian;Sainan Wu;Yuzhi Zhang;Yang Wang
原特提斯洋被认为是冈瓦纳北方边缘发育的早古生代洋。然而，其在滇西南和东南亚的空间格局、俯冲方式和闭合时间仍不清楚。云南西南部和东南亚地区的原特提斯演化及其与华南广（奥-志）陆内造山作用的内在联系也缺乏制约。本文通过对西布玛苏地块、印支地块、华南东部和日本西南部早古生代地质记录的总结和分析，提出冈瓦纳北方陆缘沿着存在一条巨型奥陶-志留纪岩浆带。对岩浆带的物源性质和运移方式进行了初步的界定。我们的数据使我们能够提出一个模式的早古生代安第斯型活动大陆边缘沿着东冈瓦纳北方边缘。这是确定东原特提斯洋南分支分别沿着云县-勐海-泰国半岛和越南中部的Tam Ky-Phouc Son缝合带向西俯冲到Sibumasu和印支地块之下，并通过三亚周边地区与日本西南部早古生代大坂俯冲带向东连接的基础。这些资料综合反映了冈瓦纳北方边缘从尼泊尔、印度西北部、西藏南部、羌塘到越南中部、横跨南印度支那和锡布马苏一带的安第斯型寒武纪（芙蓉纪）-志留纪（兰道弗里纪）沿着东向穿时和扩张的造山作用。重建了冈瓦纳北方边缘的西布玛苏和印度支那碎片以及日本西南部和华南大陆的早古生代位置，提出了早古生代原特提斯南分支俯冲作用对华南-广西陆内造山作用的远场效应。
The Prototethyan Ocean has been suggested as an Early Paleozoic Ocean developed at the Gondwana northern margin. However, its spatial pattern, subduction style and closure time in SW Yunnan and SE Asia still remain unknown. The Prototethyan evolution in SW Yunnan and SE Asia and its internal connection with the South China Kwangsian (Ordo-Silurian) intracontinental orogenesis are also poorly constrained. By summarizing and analyzing the Early Paleozoic geological records in the Sibumasu and Indochina blocks, the eastern South China and SW Japan, this paper proposes the existence of a giant Ordo-Silurian igneous belt along the Gondwana northern margin. A preliminary limitation has been obtained regarding the source nature and migration pattern of the igneous belt. Our data allow us to propose a model of the Early Paleozoic Andean-type active continental margin along the East Gondwana northern margin. This is the foundation to determine the southward subduction of the southern branch of the eastern Prototethyan Ocean underneath the Sibumasu and Indochina blocks along the Yunxian-Menghai (SW Yunnan)-Thailand Peninsula and the Tam Ky-Phouc Son suture in Central Vietnam, respectively, and the eastward linkage with the Early Paleozoic Osaka subduction zone in SW Japan across the peripheral Sanya area. These data synthetically indicate aneasterly-diachronous andpropagating Andean-type Cambrian (Furongian)-Silurian (Llandovery) orogenesis along the Gondwana northern margin from Nepal, NW India, South Tibet, Qiangtang to Central Vietnam across South Indochina and Sibumasu. This paper reconstructs the Early Paleozoic locations of the Sibumasu and Indochina fragments, as well as SW Japan and South China continent in the Gondwana northern margin, and proposes the far-field effect on the South China Kwangsian intra-continental orogenesis from the subduction of the Early Paleozoic Prototethyan southern branch.