The fault types and the implication of petrolic prospect in the west of the Qaidam Basin
Wang Yadong1 Fang Xiaomin1,2 Gao Juping1 Liu Dongliang2 |Zhang Yuezhong3 Zhang Weilin2
1.Key Laboratory of Western China's Environmental Systems|Ministry of Education of China|and College of Resources and Environment|Lanzhou University|Lanzhou 730000|2.Center of Basin Resources and Environment|Institute of Tibetan Plateau Research|Chinese Academy of Sciences|Beijing 100085|3.Research Institute of Petroleum Exploration and Development| Petroleum China Qinghai Oilfield Company|Dunhuang Gansu 736202
Analyzing the growth fault abstractly and quantificationally is helpful to understand the forming of the petrolic resource in the western Qaidam Basin and the relation with the Tibet Plateau uplift. Two main forming periods and four presenting forms to the fault evolvement of the western Qaidam Basin are found. The main forming periods are E1＋2?N and N?Q，the former started in the Mesozoic and ended at the Xia Youshashan formation(Fm.)(～15 Ma)，and the later started at the Shang Youshashan Fm.，especially from the Shizigou Fm.(～8.2 Ma)to nowadays，the activity to the faults became strong rapidly. The four fault patterns are the primo growth fault develops in the lower tectonic layer，the secondary upgrowths in the upper tectonic layers，the third growth fault runs through the lower and upper tectonic layers，the fourth is subsequent one?off fault，which impenetrate the lower and upper tectonic layers. These faults in the western Qaidam Basin，corresponding to the phase uplift of the Tibetan Plateau，can control the petrolic transportation，accumulation，conservation and reconstruction，and conduce to petrolic prospection in the west of the Qaidam Basin.