通过对黄陵地区新元古代侵入岩的岩石地球化学、同位素地球化学、矿物化学特征分析,探讨形成的构造背景及其温压条件,估算酸性花岗岩平均剥露速率。并结合年代学,认为酸性花岗岩是晋宁造山的产物,其形成与超大陆聚合有关,而隆升正处于Ro...通过对黄陵地区新元古代侵入岩的岩石地球化学、同位素地球化学、矿物化学特征分析,探讨形成的构造背景及其温压条件,估算酸性花岗岩平均剥露速率。并结合年代学,认为酸性花岗岩是晋宁造山的产物,其形成与超大陆聚合有关,而隆升正处于Rod in ia超大陆的裂解即将开始时期,七里峡岩墙群的侵位则标志着Rod in ia大陆的裂解已经开始。展开更多
（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
文摘通过对黄陵地区新元古代侵入岩的岩石地球化学、同位素地球化学、矿物化学特征分析,探讨形成的构造背景及其温压条件,估算酸性花岗岩平均剥露速率。并结合年代学,认为酸性花岗岩是晋宁造山的产物,其形成与超大陆聚合有关,而隆升正处于Rod in ia超大陆的裂解即将开始时期,七里峡岩墙群的侵位则标志着Rod in ia大陆的裂解已经开始。
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.
