New Discovery of the Early Cretaceous Volcanic Rocks on the Barton Peninsula,King George Island,Antarctica and Its Geological Significance  

作　　者：ZHENG Xiangshen SANG Haiqing QIU Ji LIU Jiaqi LEE Jong Ik KIM Hyeoncheol 

机构地区：[1]Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [2]Polar Research Center,Korea Ocean Research and Development Institute,Seoul 425-600,Korea

出　　处：《Acta Geologica Sinica(English Edition)》2000年第2期176-182,共7页地质学报（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China(49672107);CAS(KZ951-A1-205-02);the Ministry of Science and Technology of China(98-927-01-06-05);This work was also supported by the Ministry of Maritime Affairs and Fisheries,Korea through KORDI(PP98001 04);The 9th Korean Antarctic Re-search Program and the King Sejong Station headedby Dr.Yeadong Kim provided logistic support duringthe expedition.

摘　　要：Ages determined with the 40Ar/39Ar isotopic system affirms the Early Cretaceous volcanic activity in the Barton Peninsula, King George Island, Antarctica. Two specimens of basaltic andesite collected from the lower-most volcanic sequence of the peninsula were irradiated and analyzed in different experiments, yielding an identical age spectrum, and two magmatic thermal events of the Early Cretaceous (120.4±1.6 Ma, 119±1 Ma) and Early Tertiary (53.1±1.5 Ma, 52±1 Ma) are distinguished. The former is interpreted to represent the primary cooling age of basaltic andesite, whereas the latter is the thermal reset age caused by the intrusion of granitic pluton. These new ages clearly indicate that volcanism was active during the Early Cretaceous on the Barton Peninsula and that intensive hydrothermal alteration and mineralization of Mesozoic volcanic rocks resulted from Tertiary magmatism.Ages determined with the 40Ar/39Ar isotopic system affirms the Early Cretaceous volcanic activity in the Barton Peninsula, King George Island, Antarctica. Two specimens of basaltic andesite collected from the lower-most volcanic sequence of the peninsula were irradiated and analyzed in different experiments, yielding an identical age spectrum, and two magmatic thermal events of the Early Cretaceous (120.4±1.6 Ma, 119±1 Ma) and Early Tertiary (53.1±1.5 Ma, 52±1 Ma) are distinguished. The former is interpreted to represent the primary cooling age of basaltic andesite, whereas the latter is the thermal reset age caused by the intrusion of granitic pluton. These new ages clearly indicate that volcanism was active during the Early Cretaceous on the Barton Peninsula and that intensive hydrothermal alteration and mineralization of Mesozoic volcanic rocks resulted from Tertiary magmatism.

关 键 词：ANTARCTICA Barton Peninsula volcanic rocks ^(40)Ar/^(39)Ar age 

分 类 号：P588.11[天文地球—岩石学]