Tectono-thermal Evolution in the Bachu Uplift,Tarim Basin,China  

作　　者：QIU Nansheng JIANG Guang MEI Qinghua WANG Shengjun 

机构地区：[1]State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China [2]Basin and Reservoir Research Center, China University of Petroleum, Beijing 102249, China

出　　处：《Acta Geologica Sinica(English Edition)》2010年第5期1286-1293,共8页地质学报（英文版）

基　　金：The National Major Fundamental Research and Development Project(2005CB422102);Notional Key Project for Oil and Gas(2008ZX05007-03);Key Project of SINOPEC provided financial support for this work

摘　　要：The thermal evolution of source rocks in the Paleozoic has long been a problem to petroleum exploration in the Bachu uplift, Tarim basin, since the thermal history in the Paleozoic could not be rebuilt objectively due to lack of effective thermal indicators in the Lower Paleozoic successions. The apatite and zircon （U-Th）/He thermochronometry can be used as a new kind of technique to study the thermal history and tectonic uplift of sedimentary basins. Based on the measured apatite and zircon （U-Th）/He ages, apatite fission track data and equivalence vitrinite reflectance （%EVRo）, the tectonothermal histories in 5 wells of the Bachu uplift were modeled. The modeling results show that there was relatively high gradient at the Early Paleozoic in the Bachu uplift and it decreased gradually during the entire Paleozoic： 33-35℃/km in the Cambrian- Ordovician, 32-33℃/km in the Silurian-Devonian, 30-32℃/km at the end of Carboniferous and 27.5- 31℃/km at the end of Permian. Therefore, the thermal history can be modeled by combining multiple thermal indicators of AFT, （U-Th）/He ages and EVRo data. Especially, this provides a new method to rebuild the thermal history for the Low Paleozoic carbonate successions in the Tarim Basin.The thermal evolution of source rocks in the Paleozoic has long been a problem to petroleum exploration in the Bachu uplift, Tarim basin, since the thermal history in the Paleozoic could not be rebuilt objectively due to lack of effective thermal indicators in the Lower Paleozoic successions. The apatite and zircon （U-Th）/He thermochronometry can be used as a new kind of technique to study the thermal history and tectonic uplift of sedimentary basins. Based on the measured apatite and zircon （U-Th）/He ages, apatite fission track data and equivalence vitrinite reflectance （%EVRo）, the tectonothermal histories in 5 wells of the Bachu uplift were modeled. The modeling results show that there was relatively high gradient at the Early Paleozoic in the Bachu uplift and it decreased gradually during the entire Paleozoic： 33-35℃/km in the Cambrian- Ordovician, 32-33℃/km in the Silurian-Devonian, 30-32℃/km at the end of Carboniferous and 27.5- 31℃/km at the end of Permian. Therefore, the thermal history can be modeled by combining multiple thermal indicators of AFT, （U-Th）/He ages and EVRo data. Especially, this provides a new method to rebuild the thermal history for the Low Paleozoic carbonate successions in the Tarim Basin.

关 键 词：（U-Th）/He THERMOCHRONOMETRY APATITE ZIRCON fission track equivalence vitrinitereflectance （%EVRo） Bachu uplift 

分 类 号：P314.2[天文地球—固体地球物理学] P618.130.1[天文地球—地球物理学]