新疆三塘湖盆地构造-热史研究

The tectonic-thermal evolution of the Santanghu Basin

目的以新疆三塘湖盆地为例,探讨复杂叠合盆地的盆地构造．热演化历程。方法多种热指标相互印证,采用Easy舶％模型进行热史反演。结果三塘湖盆地自晚古生代以来经历了海西、燕山、喜马拉雅期等多期不同构造运动的改造;盆地热演化相应划分为二叠纪的急速升温阶段, 三叠纪-早白垩世的缓慢降温阶段,第三纪至现今的基本稳定阶段;早-中二叠世地温梯度高达 4．4-5．2℃／hm,三叠纪一侏罗纪地温梯度3．12-3．93℃／hm,白垩纪以后地温梯度与现今地温梯度相差不大,2．2-2．8℃／hm。结论构造运动的发生期是盆地热体制发生转变的重要时期,此时盆地地温场发生变化,并影响到盆地有机质的演化。

Aim To study Sangtanghu Basin as a superimpose basin which deposited terrestrial sediment of Mesozoic-Cenozoic and has a complicated structural evolutionary history. Methods Based on thermal indicator, Easy Ro% model can be adopted to carry out the inversion of thermal history. Results The basin was undergone multiperiod of tectonic movement such as hercynian, Indo-China, Yanshanian, Himalayan. The thermal evolution of the basin is distributed three stages correspondingly, including sharp heating-up process of Permian, gradual cooling process of Triassic to Early-Cretaceous and elementary stable stage of Tertiary to present. The Early-Middle Permian gradient reached 4.4 -5.2 ℃/hm, induced by local magmatic activities;Triassic-Jurassic gradient is normal （3.12 -3.93℃/hm）. The thermal gradient distributed nearly the the same with the present day＇s since Cretaceous, which is range of 2.2 - 2.8℃/hm. Conclusion The happening of these movements is the transforming time of thermal regime, and has the great effects on ground temperature field and organic evolution of the basin.