巴基斯坦东部海域中-新生代沉积研究进展

Research progress of the Meso-Cenozoic sedimentary evolution in eastern Pakistan sea

巴基斯坦海域地处全球三大板块交汇区域,地质历史时期经历过复杂的构造-沉积演化;新生代以来,印度板块与欧亚板块碰撞导致喜马拉雅快速隆升,并在巴基斯坦东部海域发育世界第2大深水扇-印度扇;此外,还位于亚洲两大季风区之一的印度季风区,是研究"构造-沉积-气候"耦合问题的天然有利场所。通过归纳总结前人研究成果,对巴基斯坦东部海域中-新生代沉积研究现状进行了综述,提出了该区尚存争议的主要问题和下一步研究方向。目前,针对巴基斯坦东部海域沉积研究主要有4大方向:中新世以来印度扇沉积研究现状;中-新生代其他典型地质体沉积研究现状;晚第四纪末次浊流沉积研究现状;构造-沉积-气候耦合研究现状。相比较而言,对于德干玄武岩之下的中生代沉积、典型沉积体系之外的区域沉积演化、陆域-海域沉积体系对比等方面报道较少,尚需更加深入地研究。

The East Pakistan sea area, located in the junction of three major plates of the world, has experienced complex tectonic-sedimentary evolution in history. Since Cenozoic era, the collision between the Indian plate and the Eurasian plate has been accelerated, that led to the rapid uplifting of the Himalaya, the form of the Indus deepwater fan, the second largest in the world, and the development of the sea off the Pakistan land. In addition to it,the area is heavily influenced by Indian monsoon as one of the two major monsoon regions in Asia. It is indeed the unique place in the world for study of the coupling relationship and interaction among the tectonic, sedimentary and climatic factors. Upon the basis of previous research results, we summarized in this paper the current research status of sedimentary evolution of the Mesozoic and Cenozoic basins in the Eastern Pakistan sea, put forward some main problems remained in controversy and made suggestions for future researches. Four main research interests and directions are put in front of us, i.e, the Indus fan since Miocene;the typical Meso-Cenozoic sedimentary geological bodies;the latest Quaternary turbidite sedimentology and the interaction of tectonic, sedimentation and climate. So far, few reports are available concerning the Mesozoic sediments beneath the Deccan basalt, the regional sedimentary evolution out of the depositional system, and the correlation of continental-marine sedimentary systems. Further investigations should be accelerated.