天山-阿尔泰地区古生代构造及相关的内生成矿作用

探讨天山-阿尔泰地区大地构造及其相关的内生成矿作用是一个重要而又有趣的研究课题.阿尔泰地区属于早古生代碰撞带,天山地区属于晚古生代早期(晚泥盆世一早石炭世)碰撞带,均为区域性近南北向缩短-碰撞作用的结果.在晚泥盆世一早石炭世,阿尔泰地区近NW向区域性断层呈现右行走滑的特征,天山地区近EW向的区域性断层表现为逆断层的活动.但在晚石炭世一早二叠世,受乌拉尔碰撞带挤压作用远程效应的影响,该地区受到较弱的向东挤压的作用,阿尔泰地区NW向断层转变成左行走滑断层,天山地区近EW向断层则转变为右行走滑断层,使该区岩石发生适度的破碎,以致形成大量世界著名的内生金属矿床.对于亚洲大陆来说,碰撞作用最强烈的时期并不一定是内生金属成矿作用最有利的阶段,应该审慎地对待所谓的“造山带成矿作用假说”.最后,笔者还对该区深部隐伏内生金属矿床的找寻提出了一些建议.

Paleozoic tectonics and its related endogenic metallogeny in Tianshan-Altay region

The study of the Paleozoic tectonics and endogenic metallogeny in the Tianshan-Altay region constitutes an important and interesting project. The Altay area belongs to Early Paleozoic collision zone, and the Tianshan area belongs to the early period of Late Paleozoic (Late Devonian - Early Carboniferous) collision zone; they both resulted from nearly NS-trending shortening and collision. However, influenced by the distant effect of the compressional action of the Ural collision belt in the Late Carboniferous-Early Permian period, the Tianshan-Altay region experienced weak eastward compression, resulting in the change of NW-trending faults into sinistral strike-slip faults and the conversion of nearly EW-trending faults into dextral strike-slip ones as well as the crushing of the rocks to a certain extent, thus forming a lot of world-famous endogenic metallogenic ore deposits. In Asian continent, the strongest collision period is not necessarily the most favorable period for endogenic metallogeny, and therefore the "orogenic metallogeny hypothesis" should be treated carefully. Some suggestions concerning the prospecting for concealed endogenic metallogenic ore deposits are also put forward in this paper.