The thermal history of the Qinshui Basin has been studied by using the fission-track analysis of apatite and zircon, integrated analysis of tectonic evolution, magmatic activity and other palaeogeothermal analysis dat...The thermal history of the Qinshui Basin has been studied by using the fission-track analysis of apatite and zircon, integrated analysis of tectonic evolution, magmatic activity and other palaeogeothermal analysis data. Results indicate that the palaeogeothermal gradient between the late-Paleozoic era and the medium-Mesozoic era is relatively low and the palaeogeothermal gradient in the late-Mesozoic is up to 5.56癈/100 m in the middle, and the values are relatively higher in the north and south margins of the basin, reaching over 8.00℃/100 m, which indicates that there was an anomalous tectonic thermal event in the thermal history of Qinshui Basin. This event happened in 110-140 Ma, and the main peak value was between 120 and 140 Ma. This anomalous tectonic thermal event is controlled by the strengthening thermal mobility of the lithosphere and magmatic intrusion. The maturity of the Permo-Carboniferous coal series mainly was controlled by this anomalous thermal field. The apatite fission track date of samples across the basin shows that a rapid tectonic uplifting with cooling existed 26.2-11.5 Ma ago and the upliftings in the north and south of the basin happened earlier than that in the middle. The Permo-Carboniferous strata had been completely annealed in the early 50 Ma, palaeotemperature over 125℃. Since then, especially from Oligocene-Miocene epoch, the strata which experienced large-scale tectonic upliftings with rapid cooling have been kept out of the annealing belt (70-125℃) in a relative low temperature environment. The late Mesozoic tectonic thermal event control hydrocarbon production peak (late Jurassic to early Cretaceous period) of Permo-Carboniferous strata in Qinshui Basin. When the strata experienced upliftings with rapid cooling since Oligocene-Miocene epoch, the hydrocarbon generation of coal series had stopped.展开更多
A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geote...A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geotemperature distribution are burial depth of the basement, heat flow, magmatic activities, as well as tectonic movement, having a rugulation to be higher in the east and north, lower in the west and south, as well as higher in the past and lower at the present. The heat of the mantle source and the Indo-China tectonic thermal event have extremely influenced matura-tion of source rocks of the upper Lower Permian and the Middle and Upper Triassic in the lndo-China epoch. While, the geothermal gradient and the weak tectonic geothermal event of the Early Yanshan Movement provided necessary heat for the maturation of source rock in coal-bearing strata of the Middle and Lower Jurassic.展开更多
文摘The thermal history of the Qinshui Basin has been studied by using the fission-track analysis of apatite and zircon, integrated analysis of tectonic evolution, magmatic activity and other palaeogeothermal analysis data. Results indicate that the palaeogeothermal gradient between the late-Paleozoic era and the medium-Mesozoic era is relatively low and the palaeogeothermal gradient in the late-Mesozoic is up to 5.56癈/100 m in the middle, and the values are relatively higher in the north and south margins of the basin, reaching over 8.00℃/100 m, which indicates that there was an anomalous tectonic thermal event in the thermal history of Qinshui Basin. This event happened in 110-140 Ma, and the main peak value was between 120 and 140 Ma. This anomalous tectonic thermal event is controlled by the strengthening thermal mobility of the lithosphere and magmatic intrusion. The maturity of the Permo-Carboniferous coal series mainly was controlled by this anomalous thermal field. The apatite fission track date of samples across the basin shows that a rapid tectonic uplifting with cooling existed 26.2-11.5 Ma ago and the upliftings in the north and south of the basin happened earlier than that in the middle. The Permo-Carboniferous strata had been completely annealed in the early 50 Ma, palaeotemperature over 125℃. Since then, especially from Oligocene-Miocene epoch, the strata which experienced large-scale tectonic upliftings with rapid cooling have been kept out of the annealing belt (70-125℃) in a relative low temperature environment. The late Mesozoic tectonic thermal event control hydrocarbon production peak (late Jurassic to early Cretaceous period) of Permo-Carboniferous strata in Qinshui Basin. When the strata experienced upliftings with rapid cooling since Oligocene-Miocene epoch, the hydrocarbon generation of coal series had stopped.
文摘A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geotemperature distribution are burial depth of the basement, heat flow, magmatic activities, as well as tectonic movement, having a rugulation to be higher in the east and north, lower in the west and south, as well as higher in the past and lower at the present. The heat of the mantle source and the Indo-China tectonic thermal event have extremely influenced matura-tion of source rocks of the upper Lower Permian and the Middle and Upper Triassic in the lndo-China epoch. While, the geothermal gradient and the weak tectonic geothermal event of the Early Yanshan Movement provided necessary heat for the maturation of source rock in coal-bearing strata of the Middle and Lower Jurassic.
