Phanerozoic plate boundaries in mainland SE Asia, the Himalayas and Tibet
Phanerozoic plate boundaries in mainland SE Asia, the Himalayas and Tibet
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DOI：
10.1144/gsjgs.138.2.0109
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发表时间：
1981-03
影响因子：
2.7
通讯作者：
A. Mitchell
中科院分区：
文献类型：
--
作者：
A. Mitchell
最近获得的关于西藏、云南和缅甸的地质资料有助于识别显生宙俯冲系统和横跨东南亚大陆的冈瓦大陆的两个碎片。区内发现一个寒武纪俯冲系统和5个中生代-早新生代碰撞带。印度支那、泰国东部和西藏中部在早三叠世与中国发生碰撞；东南亚西部和S西藏在二叠纪或早三叠世从冈瓦朗分离出来，在晚三叠世与亚洲发生碰撞；缅甸西部岛弧体系在侏罗纪与亚洲发生碰撞。印支布尔曼山脉东部上三叠统复理石和片岩在侏罗纪-早白垩世向东俯冲并形成弧后冲断带时，向缅甸西部增生。白垩纪大印度岛弧杂岩与北缘碰撞，始新世早期与西藏碰撞后，缅甸西部沿萨甘-那敏山脊逆冲断层向北移动约450公里。区内三条主要锡花岗岩带和斑岩铜矿床的形成是在俯冲体系和碰撞带内特定的构造环境中形成的。
Recently available geological data on Tibet, Yunnan and Burma facilitate recognition of Phanerozoic subduction systems and two continental fragments of Gondwanaland which extend through mainland SE Asia. A Cambrian subduction system and 5 Mesozoic-early Caenozoic collision belts are identified in the region. Indochina, eastern Thailand and Central Tibet accreted to China in the early Triassic; western SE Asia and S Tibet separated from Gondwanaland in the Permian or early Triassic and collided with Asia in the late Triassic, and the western Burma island arc system collided with Asia in the Jurassic. Upper Triassic flysch and schist in the eastern Indoburman Ranges were accreted to western Burma in the Jurassic-early Cretaceous during eastward subduction and formation of a back-arc thrust belt. Following collision of Greater India with arc complexes to the N in the Cretaceous, and with Tibet in the early Eocene, western Burma moved northwards about 450 km along the Sagaing-Namyin ridge-thrust transform fault. Formation of the 3 major belts of tin granites and the porphyry copper deposits in the region took place in specific tectonic settings within the subduction systems and collision belts.