The Meso-Tethys was a late Paleozoic to Mesozoic ocean basin between the Cimmerian continent and Gondwana. Part of its relicts is exposed in the Bangong–Nujiang suture zone, in the north-central Tibetan Plateau, that played a key role in the evolution of the Tibetan plateau before the India-Asia collision. A Penrose-type ophiolitic sequence was newly discovered in the Ren Co area in the middle of the Bangong–Nujiang suture zone, which comprises serpentinized peridotites, layered and isotropic gabbros, sheeted dikes, pillow and massive basalts, and red cherts. Zircon U-Pb dating of gabbros and plagiogranites yielded 206Pb/238U ages of 169–147 Ma, constraining the timing of formation of the Ren Co ophiolite. The mafic rocks (i.e., basalt, diabase, and gabbro) in the ophiolite have uniform geochemical compositions, coupled with normal mid-ocean ridge basalt-type trace element patterns. Moreover, the samples have positive whole-rock εNd(t) [+9.2 to +8.3], zircon εHf(t) [+17 to +13], and mantle-like δ18O (5.8–4.3‰) values. These features suggest that the Ren Co ophiolite is typical of mid-ocean ridge-type ophiolite that is identified for the first time in the Bangong–Nujiang suture zone. We argue that the Ren Co ophiolite is the relic of a fast-spreading ridge that occurred in the main oceanic basin of the Bangong–Nujiang segment of Meso-Tethys. Here the Meso-Tethyan orogeny involves a continuous history of oceanic subduction, accretion, and continental assembly from the Early Jurassic to Early Cretaceous.

中文翻译：

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青藏高原中北部Meso-Tethys缝合带中的首个中洋脊型蛇绿岩

中生特提斯是介于西里米亚大陆和冈瓦纳之间的晚古生代至中生代海盆。它的部分遗物暴露在青藏高原中北部的Bangong-Nujiang缝合带中，该区域在印度-亚洲碰撞之前对青藏高原的演变起了关键作用。在班公–怒江缝合带中部的伦科地区，新发现了一种彭罗斯型的蛇纹岩序列，其中包括蛇纹化橄榄岩，层状和各向同性的辉长岩，​​堤坝，枕形和块状玄武岩以及红石。辉长岩和斜长花岗岩的锆石U-Pb测年产生了年龄为169-147 Ma的206Pb / 238U年龄，限制了Ren Co蛇绿岩的形成时间。蛇绿岩中的镁铁质岩石（即玄武岩，辉绿岩和辉长岩）具有统一的地球化学组成，加上正常的洋中脊玄武岩型微量元素分布。此外，样品的正整岩εNd（t）[+9.2至+8.3]，锆石εHf（t）[+17至+13]和地幔样δ18O（5.8-4.3‰）值。这些特征表明，Ren Co蛇绿岩是洋中脊型蛇绿岩的典型特征，这是在班公一怒江缝合带中首次发现的。我们认为，Ren Co蛇绿岩是发生在Meso-Tethys的Bangong-Nujiang段主要海洋盆地中的快速扩张山脊的遗迹。从中侏罗纪到白垩纪，中特提斯造山运动涉及海洋俯冲，吸积和大陆组装的连续历史。和类似地幔的δ18O（5.8–4.3‰）值。这些特征表明，Ren Co蛇绿岩是洋中脊型蛇绿岩的典型特征，这是在班公一怒江缝合带中首次发现的。我们认为，Ren Co蛇绿岩是发生在Meso-Tethys的Bangong-Nujiang段主要海洋盆地中的一个快速扩张的山脊的遗迹。从中侏罗纪到白垩纪早期，中特提斯造山运动涉及海洋俯冲，吸积和大陆组装的连续历史。和类似地幔的δ18O（5.8–4.3‰）值。这些特征表明，Ren Co蛇绿岩是洋中脊型蛇绿岩的典型特征，这是在班公一怒江缝合带中首次发现的。我们认为，Ren Co蛇绿岩是发生在Meso-Tethys的Bangong-Nujiang段主要海洋盆地中的快速扩张山脊的遗迹。从中侏罗纪到白垩纪早期，中特提斯造山运动涉及海洋俯冲，吸积和大陆组装的连续历史。我们认为，Ren Co蛇绿岩是发生在Meso-Tethys的Bangong-Nujiang段主要海洋盆地中的快速扩张山脊的遗迹。从中侏罗纪到白垩纪早期，中特提斯造山运动涉及海洋俯冲，吸积和大陆组装的连续历史。我们认为，Ren Co蛇绿岩是发生在Meso-Tethys的Bangong-Nujiang段主要海洋盆地中的快速扩张山脊的遗迹。从中侏罗纪到白垩纪早期，中特提斯造山运动涉及海洋俯冲，吸积和大陆组装的连续历史。