An alternative plate tectonic model for the Palaeozoic-Early Mesozoic Palaeotethyan evolution of Southeast Asia (Northern Thailand-Burma)
An alternative plate tectonic model for the Palaeozoic-Early Mesozoic Palaeotethyan evolution of Southeast Asia (Northern Thailand-Burma)
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DOI：
10.1016/j.tecto.2007.11.065
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发表时间：
2008-04-28
期刊：
影响因子：
2.9
通讯作者：
Stampfli, G. M.
中科院分区：
文献类型：
--
作者：
Ferrari, O. M.;Hochard, C.;Stampfli, G. M.
提出了东南亚地球动力学演化的另一种模型，并将其嵌入现代板块构造模型中。重建方法基于动态板块边界，受扩张速率和俯冲速度等数据的约束；在这方面，它不同于迄今提出的经典大陆漂移模型。对泰国古特提斯缝合线位置的不同解释进行了修正，认为第三系Mae Yuam断裂为缝合线的侵位。在缝合线以东，我们发现了一个印度支那派生的地体，我们保留了山泰的名字，以前用于识别东南亚存在的西默利亚地块，现在称为西布马苏。这一命名选择是根据地体的地理位置(缅甸和泰国中部的东掸邦)做出的，是为了不引入新的令人困惑的术语。东古特提斯的闭合与大洋向南俯冲有关，由于缅甸墨吉和西藏南部拉萨地块存在晚石炭世-早二叠世弧岩浆活动，以及缝合线以东没有同龄的弧岩浆活动，触发了东新特提斯作为弧后开放。为了解释柬埔寨石炭-早二叠世和二叠纪-三叠纪火山弧的存在，越南东部上三叠统的岩浆作用，以及苏门答腊岛西部下二叠-中二叠世弧火山岩的存在，我们引入了Orang Laut地体的概念。由于古太平洋向西俯冲，这些地体在博科-松马系弧后开放期间从印度支那和中国南部分离出来。这也解释了华夏西苏门答腊地块在西西布马苏地块以西的位置。(C)2008年，爱思唯尔出版。
An alternative model for the geodynamic evolution of Southeast Asia is proposed and inserted in a modern plate tectonic model. The reconstruction methodology is based on dynamic plate boundaries, constrained by data such as spreading rates and subduction velocities; in this way it differs from classical continental drift models proposed so far. The different interpretations about the location of the Palaeotethys suture in Thailand are revised, the Tertiary Mae Yuam fault is seen as the emplacement of the suture. East of the suture we identify an Indochina derived terrane for which we keep the name Shan-Thai, formerly used to identify the Cimmerian block present in Southeast Asia, now called Sibumasu. This nomenclatural choice was made on the basis of the geographic location of the terrane (Eastern Shan States in Burma and Central Thailand) and in order not to introduce new confusing terminology. The closure of the Eastern Palaeotethys is related to a southward subduction of the ocean, that triggered the Eastern Neotethys to open as a back-arc, due to the presence of Late Carboniferous-Early Permian arc magmatism in Mergui (Burma) and in the Lhasa block (South Tibet), and to the absence of arc magmatism of the same age East of the suture. In order to explain the presence of Carboniferous-Early Permian and Permo-Triassic volcanic arcs in Cambodia, Upper Triassic magmatism in Eastern Vietnam and Lower Permian-Middle Permian arc volcanites in Western Sumatra, we introduce the Orang Laut terranes concept. These terranes were detached from Indochina and South China during back-arc opening of the Poko-Song Ma system, due to the westward subduction of the Palaeopacific. This also explains the location of the Cathaysian West Sumatra block to the West of the Cimmerian Sibumasu block. (C) 2008 Published by Elsevier B.V.