羌塘中央隆起带深部结构特征研究及其意义

羌塘含油气盆地是我国境内最大的中新生代海相沉积盆地.羌塘地体内的中央隆起将盆地分为南北两个盆地.中央隆起带构造属性认识存在两种截然不同的分歧,一是伸展环境下形成,整个羌塘盆地有着同一的基底.而另一认识其是一古特提斯缝合带,其两侧盆地具有不同的演化机制.调查羌塘中央隆起的深部结构特征及其与南北两侧的盆地间的构造关系是认识羌塘盆地基底性质及其油气远景之关键科学问题.尽管羌塘地体在青藏高原形成演化过程中遭到了强烈改造,但在收集并分析已有地球物理资料基础上认为其深部结构仍有可能被完整保存.因此,利用密集宽频带流动台网观测,获取其深部结构,进而研究其与两侧盆地关系,是当前羌塘含油气盆地研究之重要突破口,同时该项研究符合我国当前国家油气资源战略评估政策.

Deep structure of the central uplift belt in the Qiangtang terrane, Tibet Plateau from broadband seismic observations

The Qiangtang basin bearing oil and gas is the largest Mesozoic-and Cenozoic marine sediment basin in China. The central uplift belt divides the Qiangtang basin into two sub-basins. So far, there are two contrary arguments for the development of the central uplift belts within Qiangtang terrane. One suggests that it formed under extension setting of the Qiangtang terrane in Carboniferous, which has the same basement with the southern Qiangtang basin and Northern Qiangtang basin. The other is that the central uplift belt was a paleotethyan suture, on its both side are present different evolution processes for the southern Qiangtang basin and norhtern Qiangtang basin. Some information from existing geophysical evidence show that the deep structure of the central uplift belt had been possible to be totally presered. To further accurately evaluate the perspective of the oil-bearing Qiangtang basin, it is very essential to survey the deep structure of the central uplift belt by broadband seismic observations. Also, the study well accords with currently macroscopical development of China.