中、新生代天山隆升过程及其与准噶尔、阿尔泰山比较研究  

The Mesozoic and Cenozoic Exhumation History of Tianshan and Comparative Studies to the Junggar and Altai Mountains

作　　者：郭召杰[1] 张志诚[1] 吴朝东[1] 方世虎[1] 张锐[1] 

机构地区：[1]北京大学造山带与地壳演化教育部重点实验室,100871

出　　处：《地质学报》2006年第1期1-15,共15页Acta Geologica Sinica

基　　金：国家重点基础研究发展规划项目(编号2001CB409804)资助成果

摘　　要：根据穿越天山地质剖面观察、系统裂变径迹(FT)测年年龄与热演化模拟结果分析,并综合前人研究结果,天山陆内造山带中、新生代主要经历2次明显的隆升事件,分别为晚侏罗世—早白垩世和中新世以来(25~0Ma)。从天山地区磷灰石FT年龄结果来看,主要记录了早期隆升年龄,但热演化模拟结果显示普遍经历了中新世以来的快速隆升。在天山北缘从盆山边缘的近25Ma开始隆升到前缘带的现今活动,表明天山陆内造山带在隆升的同时还逐渐“增生”扩展。系统研究和分析表明,东西准噶尔和阿尔泰地区则主要记录了晚中生代以来的持续隆升过程,新生代构造活动不明显或强度相对天山要弱。上述事实表明,天山及其中亚地区新生代的陆内活动是受喜马拉雅碰撞与青藏高原隆升的影响,具有向北渐弱的特征。The Tianshan is a Cenozoic intracontinental orogenic belt. To constrain its deformation history during Mesozoic and Cenozoic, we conducted integrated research on apatite fission track dating from different sections across the Tianshan. The fission-track analysis yields 2 episodic rapid cooling events, interpreted as exhumation of rocks because of the uplift of the mountains. The first is about from Late Jurassic to Early Cretaceous, and the second is about from Miocene to the present. We suggest the Cenozoic exhumation marked the uplift of the Tianshan resulting from the India-Asia collision. The Fission-track dating also shows the Tianshan is expanding by thrusting northward and southward while it is uplifting in Cenozoic. The result of the apatite fission track dating from Junggar and Altai mountains is different from those in Tianshan and they only recorded a continuous period of cooling since late Mesozoic. This paper proposes that the widespread Me^zoic denudation of the Tianshan, Junggar and Altai mountains was possibly related to extensional tectonics resulted from the collapse of the Paleozoic Tianshan orogenic belt. The fact that the Cenozoic tectonic activity in Junggar and Altai mountains is not as strong as in Tianshan implies that the Cenozoic intracontinental deformation in Central Asia is propagating northward resuhing from the India-Asia collision.

关 键 词：磷灰石 裂变径迹年龄 中新生代 隆升 天山 

分 类 号：P542.2[天文地球—构造地质学]