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本文在前人研究基础上,选择中国西部塔里木盆地、南天山及西昆仑3个重要大地构造单元交界部位的塔里木盆地西北缘喀什凹陷地区,通过对乌恰黑孜苇剖面晚新生代巨厚陆相沉积物岩石磁学特征的分析,结合岩性、古水流和物源变化等的研究,揭示了晚新生代以来区域存在5次构造活动事件,它们分别发生于渐新世末—中新世初、中中新世初、晚中新世初、晚中新世末—上新世初和上新世末—更新世。其中渐新世末—中新世初和上新世末—更新世的构造活动是该区两次重大事件,并与青藏高原构造隆升有关,前者造成西昆仑和南天山强烈上升使塔里木盆地西缘喀什凹陷地区中断了与古地中海的连通进入了陆盆沉积环境演化阶段,后者进一步造成西昆仑和南天山强烈上升、帕米尔—天山之间地壳强烈缩短以及该区现今地貌格局的形成。
Based on the previous studies, we selected the Kashi sag in the northwestern margin of the Tarim Basin at the boundary of three important tectonic units in the Tarim Basin, the South Tianshan and the West Kunlun in western China. The analysis of the magnetism of the sedimentary rocks and the combination of lithology, paleocurrent and provenance reveal that there are five tectonic events in the region since the Late Cenozoic, which occurred at the end of Oligocene - Miocene Early, Middle Miocene, early Miocene, Late Miocene - Early Pliocene and Late Pleistocene - Pleistocene. Among them, the Oligocene Eocene and Pliocene - Pleistocene tectonic activities are two major events in the area and are related to the tectonic uplift of the Qinghai-Tibet Plateau. The former caused a strong rise in the West Kunlun and South Tianshan Mountains to make the Tarim Basin The western Kashgar depression interrupted the connectivity with the Paleo Mediterranean Sea and entered the evolutionary stage of the sedimentary environment of the continental basin. The latter caused a strong rise in the West Kunlun and South Tianshan Mountains, strongly shortened the crust between the Pamir-Tianshan Mountains, and formed the present geomorphological pattern .