新疆北部大地构造研究中几个问题的评述——兼论地质图在区域构造研究中的重要意义

A review on the Paleozoic tectonic evolution of northern Xinjiang and a discussion on the important role of geological maps in tectonic study

地质图是区域地质和大地构造研究的重要基础资料,认真研读地质图是大地构造学研究的重要途径。以新疆北部几个重要构造带为例,展示了地质图的分析、研读在大地构造研究中的重要意义。基于地质图分析并结合最新的研究资料,认为东准噶尔卡拉麦里造山带的碰撞时限不晚于早石炭世（370~340Ma）;西准噶尔达拉布特构造带形成于石炭纪晚期,该带不具有板块边界或者俯冲-缝合带的属性;以巴音沟蛇绿岩带为代表的北天山洋盆的缝合时限在晚石炭世（325~316Ma）。由此推断,新疆北部地区洋盆俯冲和地体拼贴碰撞造山过程应该在晚石炭世之前完成。

Geological maps play a foundational role in the study of regional geology and tectonics.Taking northern Xinjiang as an example,this paper demonstrated the important role that geological maps play in constraining regional tectonic setting.Geological maps in combination with geochronological data from literatures demonstrate that the collisional age of Kelamaili orogenic belt is constrained to 373-343Ma,and that Darbut ophiolitic belt in western Junggar which was formed in Late Carboniferous should not be interpreted as a significant plate boundary.The time of northern Tianshan collision event between the Yili and Junggar terranes was about 325-316 Ma.It is thus concluded that the accretion of terranes in northern Xinjiang had been completed before Late Carboniferous.