（U-Th）/He dating is a newly developed low temperature thermochronometry, and it elaborately reflects cooling history of geologic body under low temperature. It can be applied to analyze thermal evolution of the sedi...（U-Th）/He dating is a newly developed low temperature thermochronometry, and it elaborately reflects cooling history of geologic body under low temperature. It can be applied to analyze thermal evolution of the sedimentary basin, combining with vitrinite reflectance and fission track. （U-Th）/He dating of apatite and zircon from drilling cores in Puguang （普光）-Maoba （毛坝） area and outcrops in Tongjiang （通江） area indicates that the Northeast Sichuan （四川） basin underwent great uplift and denudation during the Tertiary and the Quaternary. During the period, denudation rates changed from 74.8 to 172.5 m/Ma and denudation thickness was between 2 800 and 3 000 m, geotemperature gradually declined into the current temperature, passing through helium closure temperature of apatite. The uplift and denudation relate to new tectonic movement response in the Sichuan basin aroused by the Qinghai （青海）-Tibet plateau. Drilling samples above 4 000 m did not undergo closure temperature of zircon, but the samples nearly 4 000 m might approach closure temperature of zircon and all the samples underwent closure temperature of apatite. According to （U-Th）/He ages of zircon, it is concluded that the Northeast Sichuan basin began to uplift in the Late Jurassic. From the Late Jurassic to the Paleogene, Northeast Sichuan basin was in slow uplift and denudation, but the denudation of Puguang-Maoba area was earlier than that of Tongjiang area. （U-Th）/He ages of zircon indicate the denudation time of provenance areas. On the basis of paleodrainage characteristics, provenance transport and other related data, provenance areas of the clastie rocks are decided, which is worthy to be investigated further.展开更多
This study provides new low-temperature thermochronometric data, mainly apatite fission track data on the basement rocks in and adjacent to the Talas-Fergana Fault, in the Kyrgyz Tien Shan in the first place.In the se...This study provides new low-temperature thermochronometric data, mainly apatite fission track data on the basement rocks in and adjacent to the Talas-Fergana Fault, in the Kyrgyz Tien Shan in the first place.In the second place, we also present new detrital apatite fission track data on the Meso-Cenozoic sediments from fault related basins and surrounding intramontane basins. Our results confirm multistaged Meso-Cenozoic tectonic activity, possibly induced by the accretion of the so-called Cimmerian blocks to the Eurasian margin. New evidence for this multi-staged thermo-tectonic activity is found in the data of both basement and Meso-Cenozoic sediment samples in or close to the Talas-Fergana Fault.Zircon(U-Th)/He and apatite fission track data constrain rapid Late TriassiceE arly Jurassic and Late JurassiceE arly Cretaceous basement cooling in the Kyrgyz Tien Shan around 200 Ma and 130 -100 Ma respectively. Detrital apatite fission track results indicate a different burial history on both sides of the Talas-Fergana Fault. The apatite fission track system of the Jurassic sediments in the Middle Tien Shan unit east of the Talas-Fergana Fault is not reset, while the Jurassic sediments in the Fergana Basin and Yarkand-Fergana Basin, west of the fault zone, are partially and in some cases even totally reset. The totally reset samples exhibit Oligocene and Miocene ages and evidence the Cenozoic reactivation of the western Kyrgyz Tien Shan as a consequence of the India-Eurasia convergence.展开更多
By means of the vitrinite reflectance and U-Th/He dating of apatite and zircon in cut- ting samples from the T3x-K1j formations in the Yuanba （元坝） area of Northeast Sichuan （四川） Basin, a correlation has been e...By means of the vitrinite reflectance and U-Th/He dating of apatite and zircon in cut- ting samples from the T3x-K1j formations in the Yuanba （元坝） area of Northeast Sichuan （四川） Basin, a correlation has been established between the He-derived age and depth/temperature in this area assuming helium closure temperature of apatite in this area being 95 ℃. Mesozoic strata （T3x-Kd＇） experienced helium closure temperature of apatite approaching 95 ℃, but didn＇t reach the helium closure temperature of zircon （ca. 170-190 ℃） although some reached the highest pa- laeogeothermal temperature of about 170 ℃. The Mesozoic strata in the Yuanba area experienced an important uplift and denudation during Paleogene-Neogene periods （0.2-36.4 Ma）, the erosion rate being about 109.9 m/Ma. The K1] Formation and overlying strata experienced a maximum de- nudation loss of about 4 000 m. Geotemperatures gradually fell to the helium closure temperature of apatite and then fell further to the current temperature. The thermal evolution history of this area indicates that the maximum palaeogeothermal temperature of Mesozoic strata was close to 170- 190 ℃, prior to the strata being uplifted. During the period between 176 and 36 Ma, the palaeogeo- thermal temperature fell to 95-170 ℃. and after 36 Ma, it continued to fall to the present geotem- perature of less than 95 ℃.展开更多
基金supported by the National Basic Research Pro-gram of China (No. 2005CB422102)China Petroleum and Chemical Corporation Program (P06083)
文摘（U-Th）/He dating is a newly developed low temperature thermochronometry, and it elaborately reflects cooling history of geologic body under low temperature. It can be applied to analyze thermal evolution of the sedimentary basin, combining with vitrinite reflectance and fission track. （U-Th）/He dating of apatite and zircon from drilling cores in Puguang （普光）-Maoba （毛坝） area and outcrops in Tongjiang （通江） area indicates that the Northeast Sichuan （四川） basin underwent great uplift and denudation during the Tertiary and the Quaternary. During the period, denudation rates changed from 74.8 to 172.5 m/Ma and denudation thickness was between 2 800 and 3 000 m, geotemperature gradually declined into the current temperature, passing through helium closure temperature of apatite. The uplift and denudation relate to new tectonic movement response in the Sichuan basin aroused by the Qinghai （青海）-Tibet plateau. Drilling samples above 4 000 m did not undergo closure temperature of zircon, but the samples nearly 4 000 m might approach closure temperature of zircon and all the samples underwent closure temperature of apatite. According to （U-Th）/He ages of zircon, it is concluded that the Northeast Sichuan basin began to uplift in the Late Jurassic. From the Late Jurassic to the Paleogene, Northeast Sichuan basin was in slow uplift and denudation, but the denudation of Puguang-Maoba area was earlier than that of Tongjiang area. （U-Th）/He ages of zircon indicate the denudation time of provenance areas. On the basis of paleodrainage characteristics, provenance transport and other related data, provenance areas of the clastie rocks are decided, which is worthy to be investigated further.
基金supported by a Ghent University project (BOF 015B1309)the DARIUS program+2 种基金supported by ARC DP150101730TRAX record 387. F.Isupported by state assignment project No. 0330-2016-0015
文摘This study provides new low-temperature thermochronometric data, mainly apatite fission track data on the basement rocks in and adjacent to the Talas-Fergana Fault, in the Kyrgyz Tien Shan in the first place.In the second place, we also present new detrital apatite fission track data on the Meso-Cenozoic sediments from fault related basins and surrounding intramontane basins. Our results confirm multistaged Meso-Cenozoic tectonic activity, possibly induced by the accretion of the so-called Cimmerian blocks to the Eurasian margin. New evidence for this multi-staged thermo-tectonic activity is found in the data of both basement and Meso-Cenozoic sediment samples in or close to the Talas-Fergana Fault.Zircon(U-Th)/He and apatite fission track data constrain rapid Late TriassiceE arly Jurassic and Late JurassiceE arly Cretaceous basement cooling in the Kyrgyz Tien Shan around 200 Ma and 130 -100 Ma respectively. Detrital apatite fission track results indicate a different burial history on both sides of the Talas-Fergana Fault. The apatite fission track system of the Jurassic sediments in the Middle Tien Shan unit east of the Talas-Fergana Fault is not reset, while the Jurassic sediments in the Fergana Basin and Yarkand-Fergana Basin, west of the fault zone, are partially and in some cases even totally reset. The totally reset samples exhibit Oligocene and Miocene ages and evidence the Cenozoic reactivation of the western Kyrgyz Tien Shan as a consequence of the India-Eurasia convergence.
基金supported by the National Basic Research Program of China(No.2012CB214801)China Petroleum and Chemical Corporation Program(No.P120009)
文摘By means of the vitrinite reflectance and U-Th/He dating of apatite and zircon in cut- ting samples from the T3x-K1j formations in the Yuanba （元坝） area of Northeast Sichuan （四川） Basin, a correlation has been established between the He-derived age and depth/temperature in this area assuming helium closure temperature of apatite in this area being 95 ℃. Mesozoic strata （T3x-Kd＇） experienced helium closure temperature of apatite approaching 95 ℃, but didn＇t reach the helium closure temperature of zircon （ca. 170-190 ℃） although some reached the highest pa- laeogeothermal temperature of about 170 ℃. The Mesozoic strata in the Yuanba area experienced an important uplift and denudation during Paleogene-Neogene periods （0.2-36.4 Ma）, the erosion rate being about 109.9 m/Ma. The K1] Formation and overlying strata experienced a maximum de- nudation loss of about 4 000 m. Geotemperatures gradually fell to the helium closure temperature of apatite and then fell further to the current temperature. The thermal evolution history of this area indicates that the maximum palaeogeothermal temperature of Mesozoic strata was close to 170- 190 ℃, prior to the strata being uplifted. During the period between 176 and 36 Ma, the palaeogeo- thermal temperature fell to 95-170 ℃. and after 36 Ma, it continued to fall to the present geotem- perature of less than 95 ℃.
