新疆博格达—哈尔里克山晚新生代压扭性变形与隆起成山  

The Late Cenozoic transpressional deformation and uplift of Bogda-Harlic Mountains

作　　者：朱自虎[1] 季建清[1] 徐芹芹[1] 王丽宁[1] 孙东霞[1] 龚俊峰[1] 赵磊[1] 

机构地区：[1]北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室,北京100871

出　　处：《地质科学》2010年第3期653-665,共13页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家重点基础研究发展计划项目"中亚造山带大陆动力学过程与成矿作用"(编号:2007CB411300)研究成果

摘　　要：压扭性走滑变形是陆内变形的最主要构造样式之一,并且是陆内造山系统得以形成的最基本构造样式。位于天山东部的博格达—哈尔里克山链,横亘在吐哈盆地和准噶尔盆地之间,是研究新生代山脉形成理想的野外实验室。本文结合压扭造山带的研究,通过野外地质填图、遥感解译和DEM分析,裂变径迹测试等研究,确认博格达—哈尔里克山与山脉隆起相关的断裂构造主要为北东东向和北西西向压扭性走滑断裂,认为它是晚新生代压扭造山带(transpressional orogen)。主要证据是:首先博格达—哈尔里克山与山脉隆起相关的构造变形为北东东70°走向和北西西290°走向,山脉两侧呈现向盆地方向的逆冲冲断构造,体现了近南北向为构造主压应力场特点;其次天池河床砂岩屑AFT分析出的年龄峰值集中在42.8 Ma(62.8%)、18.8 Ma(29.0%)、3.2 Ma(8.2%),表明样品所代表的流域地质体在42.8 Ma、18.8Ma、3.2 Ma经历了3次冷却事件。依据裂变径迹等年龄投影圈闭图显示博格达山裂变径迹年龄存在中间新,两边老的特点。基于相同的大地构造背景,压扭造山模式也可以解释整个天山晚新生代山脉强烈隆升。Transpressional deformation is the main style in intracontinental deformation, and is the basic pattern in the process of mountain building. Bogda-Harlik Mountains are located in eastern Tienshan（in the middle of Turpan-Hami Basin and Junggar Basin）. It is an ideal field laboratory to study the Cenozoic Mountain building. A variety of orogenic mechanisms were proposed by scholars, but contradictions still exist. Through our geological mapping, remote sensing interpretation and digital topographic analysis, two groups of strike-slip faults （ NWW and NEE respectively）are closely related to the Cenozoic uplift of Bogda-Harlic Mountains. The Bogda-Harlik Mountains should be considered as a typical transpressional orogeny. The uplift-related deformation are NEE 70° and NWW 290°,and thrust fold to the direction of the basins developed on both sides of the mountains, which indicates the nearly north-south stress field; Secondly, the age of fluvial sands from Tianchi River are concentrated at 42.8 Ma （62.8%）, 18.8 Ma（29.0% ）and 3.2 Ma（8.2% ） ,which reveals that the drainage terrains have experienced 3 different cooling phases. The map of fission-track age shows the samples with old age mainly distribute in the margin of the mountain, and the youngest in the centre area of the mountain. Based on the similar tectonic background, the transpressional orogeny mode can be also used in the interpretation of Cenozoic rapid uplift of the entire Tienshan.

关 键 词：博格达-哈尔里克山 压扭性走滑断层 造山 裂变径迹 

分 类 号：P542[天文地球—构造地质学]