HEAT FLOW AND ACCUMULATIONOF OIL/GAS POOLS IN ORDOSBASIN, NW CHINASun Shaohua(Changsha Institute of Geotectonics - Academia Sinica, Changsha, 410013, Hunan, China)heat flow feild, petroleum, Ordos basin.This paper foc...HEAT FLOW AND ACCUMULATIONOF OIL/GAS POOLS IN ORDOSBASIN, NW CHINASun Shaohua(Changsha Institute of Geotectonics - Academia Sinica, Changsha, 410013, Hunan, China)heat flow feild, petroleum, Ordos basin.This paper focuses on the heat flow field of Ordos Basin, NW China, by combin-ing experiment method of U, K and Th, heat generation, heat conductivity, etc. In the light of the comprehensive study of the experimental data and layer divisions of the crust, the average heat of Moho in Ordos Basin is 0. 37 HFU, much lower than that in North China Basin (0. 64-0. 97 HFU) or that in Songliao Basin (1.19 HFU) , NE China, showing the characteristics of the heat flow field of the stable cratonic basin. The average heat flow on the crust surface of the basin is about 1. 44 HFU, similar to that in Mesozoic diwa orogeny of the world, probably indicating that the diwa stage is soon expected in the basin. The interfaces from Moho to the surface in Ordos Basin have the same heat flow distribution-style with展开更多
The analyzing data on stratigraphic temperature measurement , thermal conductivity of the strata and radioactive heat production rate show that the present average geothermal gradient in the Ordos Basin is 2.93℃/100 ...The analyzing data on stratigraphic temperature measurement , thermal conductivity of the strata and radioactive heat production rate show that the present average geothermal gradient in the Ordos Basin is 2.93℃/100 m, and the average heat flow value is 61.78 mW/m2, which belongs to the mesothermal basin, and the value of the present geothermal gradient and heat flow in the east is higher than that in the west. The sandstone radioactive heat production rate of Zhiluo Group in Dongsheng Uranium deposits of Yimeng uplift is obviously higher in the mudstone, indicating that there exists a uranium anomaly. Based on studies of the present thermal field of the basin, the late-Mesozoic paleotemperature and paleogeothermal gradient are determined by using different kinds of paleotemperature methods. According to the anomaly of the late-Mesozoic paleotemperature gradient and magmatic event age, there was a tectonic thermal event in the early Cretaceous epoch of late-Mesozoic. This article rebuilds tectonic thermal history of different tectonic units by thermal history simulation using basin simulating software. The evolution of oil-gas and coal, and accumulation (mineralization) of mineral uranium are all controlled by the tectonic thermal history in the Ordos basin, especially by the tectonic thermal event that happened in the late Mesozoic. For both the gas source rocks of upper Paleozoic group and lower paleozoic group, the gas was largely generated in the early Cretaceous epoch of the late Mesozoic. The main petroleum generation period for Yanchang Group in Triassic system is the early Cretaceous epoch too, and the highest thermal maturity of the coal of Permo-Carboniferous, Triassic, and Jurassic reaches is the early Cretaceous epoch also. Early Cretaceous epoch is still one of the most important mineralizing periods of uranium.展开更多
There are some factors, such as the topographic relief, sedimentary thickness and thermal conductivity, magmatic activity and thermal cooling, influencing the seafloor heat flow and the evolution of lithosphere struct...There are some factors, such as the topographic relief, sedimentary thickness and thermal conductivity, magmatic activity and thermal cooling, influencing the seafloor heat flow and the evolution of lithosphere structure in southwest sub-basin （SWSB）, South China Sea. On the base of the geological structure characteristic of SWSB this paper will discuss some other factors including thermal anomaly area, dike produced by magma intrusion and lithosphere relief, by modeling and calculating. Calculating results indicate partial areas where temperature is higher than vicinity in the lithosphere, which we call thermal anomaly here containing thermal anomaly area and dike in this paper, could decrease heat flow below, increase above, and gradually increase to two sides; heat flow in upwelling parts of lithosphere is usually higher than sinking parts, and in the middle is of a gradual transition.展开更多
Thermal lithospheric thickness is an important parameter in studying the tectonic-thermal evolution of basins and plate dynamics.Based on the measured geothermal data and thermophysical properties of the rocks,the the...Thermal lithospheric thickness is an important parameter in studying the tectonic-thermal evolution of basins and plate dynamics.Based on the measured geothermal data and thermophysical properties of the rocks,the thermal lithospheric thickness of the Sichuan Basin was calculated according to the principles of heat conduction in the crust and lithospheric mantle.The calculation results revealed that the thickness of the thermal lithosphere in the Sichuan Basin is 140-190 km and is unevenly distributed.The thickness of the thermal lithosphere in central Sichuan and southwestern Sichuan is less than 160 km,while that in the western Sichuan depression and eastern Sichuan is larger(~180 km).The distribution of the thermal lithospheric thickness in the basin has a good correlation with the geological units and the thickness of the sedimentary layers.The thickness of the thermal lithosphere in the depression area,which has thick sedimentary layers and the fault-fold zone with shallow crustal deformation and thickening,are larger than that in the basement uplifted area,which has thin sedimentary layers.The calculated thermal lithospheric thickness is in good agreement with the geophysical data and reflects the stable conduction temperature field in the Sichuan Basin.The present thermal regime and thermal lithospheric thickness of the Sichuan Basin indicate that flexural thickening of the lithosphere occurred in the eastern Sichuan fault-fold belt and the Longmen Mountain-Western Sichuan depression foreland basin system,while asthenospheric uplift occurred in the central Sichuan region,which were the result of the expansion of the Xuefeng orogeny from the east and the compression of the Tibetan Plateau from the west.展开更多
基金Supported by the National Natural Sciences Foundation of China and the Chinese Academy of Science
文摘HEAT FLOW AND ACCUMULATIONOF OIL/GAS POOLS IN ORDOSBASIN, NW CHINASun Shaohua(Changsha Institute of Geotectonics - Academia Sinica, Changsha, 410013, Hunan, China)heat flow feild, petroleum, Ordos basin.This paper focuses on the heat flow field of Ordos Basin, NW China, by combin-ing experiment method of U, K and Th, heat generation, heat conductivity, etc. In the light of the comprehensive study of the experimental data and layer divisions of the crust, the average heat of Moho in Ordos Basin is 0. 37 HFU, much lower than that in North China Basin (0. 64-0. 97 HFU) or that in Songliao Basin (1.19 HFU) , NE China, showing the characteristics of the heat flow field of the stable cratonic basin. The average heat flow on the crust surface of the basin is about 1. 44 HFU, similar to that in Mesozoic diwa orogeny of the world, probably indicating that the diwa stage is soon expected in the basin. The interfaces from Moho to the surface in Ordos Basin have the same heat flow distribution-style with
文摘The analyzing data on stratigraphic temperature measurement , thermal conductivity of the strata and radioactive heat production rate show that the present average geothermal gradient in the Ordos Basin is 2.93℃/100 m, and the average heat flow value is 61.78 mW/m2, which belongs to the mesothermal basin, and the value of the present geothermal gradient and heat flow in the east is higher than that in the west. The sandstone radioactive heat production rate of Zhiluo Group in Dongsheng Uranium deposits of Yimeng uplift is obviously higher in the mudstone, indicating that there exists a uranium anomaly. Based on studies of the present thermal field of the basin, the late-Mesozoic paleotemperature and paleogeothermal gradient are determined by using different kinds of paleotemperature methods. According to the anomaly of the late-Mesozoic paleotemperature gradient and magmatic event age, there was a tectonic thermal event in the early Cretaceous epoch of late-Mesozoic. This article rebuilds tectonic thermal history of different tectonic units by thermal history simulation using basin simulating software. The evolution of oil-gas and coal, and accumulation (mineralization) of mineral uranium are all controlled by the tectonic thermal history in the Ordos basin, especially by the tectonic thermal event that happened in the late Mesozoic. For both the gas source rocks of upper Paleozoic group and lower paleozoic group, the gas was largely generated in the early Cretaceous epoch of the late Mesozoic. The main petroleum generation period for Yanchang Group in Triassic system is the early Cretaceous epoch too, and the highest thermal maturity of the coal of Permo-Carboniferous, Triassic, and Jurassic reaches is the early Cretaceous epoch also. Early Cretaceous epoch is still one of the most important mineralizing periods of uranium.
文摘There are some factors, such as the topographic relief, sedimentary thickness and thermal conductivity, magmatic activity and thermal cooling, influencing the seafloor heat flow and the evolution of lithosphere structure in southwest sub-basin （SWSB）, South China Sea. On the base of the geological structure characteristic of SWSB this paper will discuss some other factors including thermal anomaly area, dike produced by magma intrusion and lithosphere relief, by modeling and calculating. Calculating results indicate partial areas where temperature is higher than vicinity in the lithosphere, which we call thermal anomaly here containing thermal anomaly area and dike in this paper, could decrease heat flow below, increase above, and gradually increase to two sides; heat flow in upwelling parts of lithosphere is usually higher than sinking parts, and in the middle is of a gradual transition.
基金supported by the National Key Research&Development Program of China(Grant No.2017YFC0603102)the National Natural Science Foundation of China(Grant No.41772248 and 41830424)。
文摘Thermal lithospheric thickness is an important parameter in studying the tectonic-thermal evolution of basins and plate dynamics.Based on the measured geothermal data and thermophysical properties of the rocks,the thermal lithospheric thickness of the Sichuan Basin was calculated according to the principles of heat conduction in the crust and lithospheric mantle.The calculation results revealed that the thickness of the thermal lithosphere in the Sichuan Basin is 140-190 km and is unevenly distributed.The thickness of the thermal lithosphere in central Sichuan and southwestern Sichuan is less than 160 km,while that in the western Sichuan depression and eastern Sichuan is larger(~180 km).The distribution of the thermal lithospheric thickness in the basin has a good correlation with the geological units and the thickness of the sedimentary layers.The thickness of the thermal lithosphere in the depression area,which has thick sedimentary layers and the fault-fold zone with shallow crustal deformation and thickening,are larger than that in the basement uplifted area,which has thin sedimentary layers.The calculated thermal lithospheric thickness is in good agreement with the geophysical data and reflects the stable conduction temperature field in the Sichuan Basin.The present thermal regime and thermal lithospheric thickness of the Sichuan Basin indicate that flexural thickening of the lithosphere occurred in the eastern Sichuan fault-fold belt and the Longmen Mountain-Western Sichuan depression foreland basin system,while asthenospheric uplift occurred in the central Sichuan region,which were the result of the expansion of the Xuefeng orogeny from the east and the compression of the Tibetan Plateau from the west.
