MESO-CENOZOIC HEAVY MINERALS’ASSEMBLAGES IN THE SOUTHERN JUNGGAR BASIN AND ITS IMPLICATIONS FOR BASIN-OROGEN PATTERN
Fang Shihu1, Guo Zhaojie2, Jia Chengzao1, Zhang Zhicheng2, Wang Xulong3, Wang Meina2
1. Research Institute of Petroleum Exploration and Development of China, Beijing 100083; 2. School of Earth and Space Sciences, Peking University, Beijing 100871; 3. Xinjiang Oilfield Branch Company, China National Petroleum Corp., Karamay, Xinjiang 834000
The analyses of heavy minerals and their assemblages were carried in practice for two field sections in the southern Junggar Basin, well cores data and two field sections in the inner Tianshan Mountains. Different heavy minerals’assemblages and increasing of unstable heavy minerals during Late Jurassic-earliest Cretaceous, Late Cretaceous and Late Cenozoic might indicate tectonic activity during these three periods. There existed three provenance systems in the southern Junggar Basin and several separated small basin within the Tianshan Mountains during Early-Middle Jurassic. The characteristics of sedimentary systems and heavy minerals proved that the Junggar and Tarim Basins were not physiographically separated by an ancestral version of the Tianshan Mountains during Early-Middle Jurassic. From Late Jurassic to the earliest Cretaceous, the distribution of Upper Jurassic Kalazha conglomerate and Cretaceous bottom conglomerate in front of the Bogda Mountains showed a tectonically active setting and obvious uplift of Tianshan during the latest Jurassic-earliest Cretaceous, and the Bogeda Mountains became another provenance system of the southern Junggar Basin, resulting in widely varied sedimentary successions between the Tarim Basin and the southern Junggar Basin. The basin-orogen pattern of the southern Junggar Basin didn’t change greatly until the long-distance effect of India-Asia collision. The Mesozoic-Cenozoic tectonic activities and evolution of the basin-orogen pattern in the southern Junggar Basin should be related to the collision in the southern margin of the Eurasia plate.
Fang Shihu,Guo Zhaojie,Jia Chengzao et al. MESO-CENOZOIC HEAVY MINERALS’ASSEMBLAGES IN THE SOUTHERN JUNGGAR BASIN AND ITS IMPLICATIONS FOR BASIN-OROGEN PATTERN[J]. Chinese Journal of Geology, 2006, (4): 648-662.