Abstract:

Tarim Basin experienced three development stages such as Presinian geosyncline,Paleozoic platform and Meso-Cenozoic continental basin stages.In Presinian stage,the paleogeosyncline shrinked and the continental nucleus expanded continuously,thus form-ing immense Tianshan-Tarim Platform in the end of the Proterozoic.The platform was disintegrated until Early-Middle Caledonian,forming a huge oil-generation depression—Amang Depression in the north of the platform.During late Caledonian to early Hercyni-an,uplifts and depressions developed in the region,forming the North Tarim Uplift.Mid-dle Hercynian was the main stage for hydrocarbon generation and accumulation,the North Tarim Uplift continued to expand and East Tarim Uplift formed.Early Permian tectonic movement ended the development of sea basin,and stopped oil generation of Pa-leozoic source rocks.During Meso-Cenozoic,oil-generation depressions formed in north and south sides of Xinhe Uplift which became a large Mesozoic oil accumulation zone of drape structural type in Indo-Sinian and Yenshanian stages.Since Indian and Asian Plates compressed and collided each other,Tianshan and Kunlun Mountains folded systems up-lifted intensely,and the sediments in the associated piedmont depression unceasingly over-lapped towards Tarim Basin,thus forming favourable caprocks for Meso-Cenozoic hydro-carbon resources in the basin,leading to the oil generation of Paleozoic source rocks.The Folded-faults formed in the end of Himalayan stage prepared necessary conditions for hy-drocarbon migration and accumulation again.