特提斯中西段古生代洋陆格局与构造演化

Paleozoic tectonic framework and evolution of the central and western Tethys

关键词:  特提斯中西段  古生代蛇绿岩带  增生杂岩带  构造格架  构造演化

Key words:  central and western Tethys  Paleozoic ophiolite zone  accretionary complex zone  tectonic framework  tectonic evolution.

摘要:

笔者根据国内外研究进展和区域地质对比，将特提斯中西段的古生代构造域划分为Iapetus-Tornquist洋加里东造山带、Rheic洋华力西期造山带、乌拉尔-天山中亚造山带和古特提斯Pontides-高加索-Mashhad造山带，并提出4个初步认识：（1） Rodinia超大陆在新元古代裂解形成的原特提斯大洋在欧洲以Iapetus和Tornquist缝合带为代表，它们在约420 Ma闭合形成加里东造山带，与我国秦祁昆造山系相似；（2） Rheic洋类似于特提斯东段的龙木错-双湖-昌宁-孟连洋，为古生代的特提斯主大洋，而泥盆纪形成的古特提斯洋实际上为主洋盆衍生的分支洋盆之一，Rheic洋的各分支洋盆在320~310 Ma闭合，形成华力西造山带和Pangea超大陆；（3）南阿尔卑斯Plankogel带、土耳其北部Pontides带和伊朗北部Rasht-Mashhad为古特提斯缝合带，代表泥盆纪—二叠纪的洋盆，晚石炭世—早三叠世丝绸之路岩浆弧与我国羌塘中部的望果山火山弧相对应；（4）特提斯中西段的基梅里造山带和羌塘中部的印支期造山带为古特提斯增生型造山带的典型代表。

Abstract:

The Paleozoic tectonic domain in central and western Tethys is divided in this paper on the basis of the results of research and regional geological correlation at home and abroad,into the Iapetus tornquist Caledonian orogenic belt, the Rheic Variscan orogenic belt and the Ural Tianshan Central Asia orogenic belt.The results of research in this paper led us to the following conclusions. (1) The Proto-Tethyan ocean formed by the break-up of Rodinia supercontinent during the Neoproterozoic is represented by the Iapetus and Tornquist suture zones in Europe, which closed to form Caledonian orogenic zones at ~ 420 Ma, similar to the Qinling-Qilian-Kunlun orogenic zones in China.(2) The Rheic Ocean is similar to the Longmucuo-Shuanghu-Changning-Mmenglian Ocean in the eastern part of the Tethys. It was the major Paleozoic Tethyan Ocean and the Paleo-Tethys formed during the Devonian was actually one of its sub-branches. All of the Rheic sub-branch oceans closed at 320~ 310 Ma, forming the Variscan orogenic zone and Pangea supercontinent.(3) The Plankogel zone in the Southern Alps, the pontides zone in northern Turkey and the Rasht -Mashhad zone in northern Iran are Paleo-Tethyan suture zones, representing Devonian-Permian ocean basins. The Late Carboniferous-Early Triassic Silk Road Arc corresponds to the Wangguoshan volcanic arc in central Qiangtang, China.(4) The Cimmerides zone in central and western Tethys and the Indosinian zone in central Qiangtang are typical accretionary orogenic zones of Paleo-Tethys.