Ediacaran 2,500-km-long synchronous deep continental subduction in the West Gondwana Orogen
Ediacaran 2,500-km-long synchronous deep continental subduction in the West Gondwana Orogen
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DOI：
10.1038/ncomms6198
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发表时间：
2014-10-01
影响因子：
16.6
通讯作者：
Basei, Miguel A. S.
中科院分区：
文献类型：
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作者：
Ganade de Araujo, Carlos E.;Rubatto, Daniela;Basei, Miguel A. S.
西冈瓦纳造山带的深度侵蚀是一个主要的大陆碰撞带，暴露了许多深俯冲岩石，如榴辉岩。这些榴辉岩的位置标志着碰撞碰撞带之间的缝合带，变质作用的年龄限制了从俯冲为主的构造到大陆碰撞和造山作用的转变。在这里，我们调查的变质条件和年龄的高压和超高压榴辉岩从马里，多哥和东北-巴西，并证明大陆俯冲发生在2000万年内超过至少2,500公里长的一段造山带在埃迪卡拉纪。我们认为这是地质记录中大规模深大陆俯冲和随后出现喜马拉雅山规模山脉的最早证据。埃迪卡拉纪晚期这些山脉的上升和随后的侵蚀是完美的时机，以提供沉积物和营养物质，这些沉积物和营养物质被认为是地球上可持续生命随后进化所必需的。
The deeply eroded West Gondwana Orogen is a major continental collision zone that exposes numerous occurrences of deeply subducted rocks, such as eclogites. The position of these eclogites marks the suture zone between colliding cratons, and the age of metamorphism constrains the transition from subduction-dominated tectonics to continental collision and mountain building. Here we investigate the metamorphic conditions and age of high-pressure and ultrahigh-pressure eclogites from Mali, Togo and NE-Brazil and demonstrate that continental subduction occurred within 20 million years over at least a 2,500-km-long section of the orogen during the Ediacaran. We consider this to be the earliest evidence of large-scale deep-continental subduction and consequent appearance of Himalayan-scale mountains in the geological record. The rise and subsequent erosion of such mountains in the Late Ediacaran is perfectly timed to deliver sediments and nutrients that are thought to have been necessary for the subsequent evolution of sustainable life on Earth.