Previous studies proposed thermal simulation experiment to investigate the annealing characteristics of fission tracks in igneous zircon samples.However,basic research about detrital zircon fission track was relativel...Previous studies proposed thermal simulation experiment to investigate the annealing characteristics of fission tracks in igneous zircon samples.However,basic research about detrital zircon fission track was relatively weak.This study discussed the initial track length,annealing temperature and annealing model of zircon fission track by using the measured track lengths obtained from natural borehole samples in the sedimentary basins with different thermal background.The results show that the initial track length of zircon fission track is 12.97 μm.The total annealing temperature(Ttotal) of zircon fission track derived from the evolutionary curve of the mean track lengths is approximately 400 ℃.The temperature ranges of 120-230 ℃ corresponds to the partial annealing zone(PAZ),and is lower than the range obtained through thermal annealing experiments.The annealing model is modified based on the measured track lengths.In addition,a functional formula about the mean track length,annealing temperature,and geological time is proposed,and the fitted values of track lengths consist with the measured track lengths in this study.By properly understanding the initial track length and annealing behavior of zircon fission track can provide a significant guidance for the study of hydrocarbon accumulation in sedimentary basins.展开更多
Zircon(U-Th)/He thermochronometry was used as an effective indicator to study the thermal history of deep sedimentary basins with high temperatures.Zircon He ages and closure temperatures are very important parameters...Zircon(U-Th)/He thermochronometry was used as an effective indicator to study the thermal history of deep sedimentary basins with high temperatures.Zircon He ages and closure temperatures are very important parameters.In this paper,detrital zircon He closure temperature was studied by establishing the evolutionary pattern between zircon He ages and burial depth of borehole samples obtained from the Cenozoic strata in the Bohai Bay and Tarim basins,which have different thermal settings.The results show that the zircon He closure temperature of natural evolution samples is 200℃,which is higher than the temperature obtained from thermal simulation experiments(183℃).The temperature range of 140-200℃corresponds to the zircon helium partial retention zone.By properly understanding zircon He closure temperatures,zircon(U-Th)/He thermochronometry can provide a correct explanation of the He ages,and significant guidance in the study of the evolution of source rocks and the process of hydrocarbon accumulation in deep sedimentary basins.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41802154 and 41830424)the State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing(No.PRP/open-1902)+1 种基金the Natural Science Foundation Project of Chongqing,Chongqing Science and Technology Commission(No.cstc2019jcyj-msxm X0764)the Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJQN201901533)。
文摘Previous studies proposed thermal simulation experiment to investigate the annealing characteristics of fission tracks in igneous zircon samples.However,basic research about detrital zircon fission track was relatively weak.This study discussed the initial track length,annealing temperature and annealing model of zircon fission track by using the measured track lengths obtained from natural borehole samples in the sedimentary basins with different thermal background.The results show that the initial track length of zircon fission track is 12.97 μm.The total annealing temperature(Ttotal) of zircon fission track derived from the evolutionary curve of the mean track lengths is approximately 400 ℃.The temperature ranges of 120-230 ℃ corresponds to the partial annealing zone(PAZ),and is lower than the range obtained through thermal annealing experiments.The annealing model is modified based on the measured track lengths.In addition,a functional formula about the mean track length,annealing temperature,and geological time is proposed,and the fitted values of track lengths consist with the measured track lengths in this study.By properly understanding the initial track length and annealing behavior of zircon fission track can provide a significant guidance for the study of hydrocarbon accumulation in sedimentary basins.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41802154 and 41830424)the Foundation of State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing (Grant No. PRP/open1902)
文摘Zircon(U-Th)/He thermochronometry was used as an effective indicator to study the thermal history of deep sedimentary basins with high temperatures.Zircon He ages and closure temperatures are very important parameters.In this paper,detrital zircon He closure temperature was studied by establishing the evolutionary pattern between zircon He ages and burial depth of borehole samples obtained from the Cenozoic strata in the Bohai Bay and Tarim basins,which have different thermal settings.The results show that the zircon He closure temperature of natural evolution samples is 200℃,which is higher than the temperature obtained from thermal simulation experiments(183℃).The temperature range of 140-200℃corresponds to the zircon helium partial retention zone.By properly understanding zircon He closure temperatures,zircon(U-Th)/He thermochronometry can provide a correct explanation of the He ages,and significant guidance in the study of the evolution of source rocks and the process of hydrocarbon accumulation in deep sedimentary basins.
