| The purpose of this paper is determining Ar-Ar standard Cenozoic dating material. Basing on the previous studies, I selected three samples, respectively sanidine in Yulin Mountain of Gerze, Ngari of northern Tibet, Biotite in Polan of Southern Tibet andsanidine in Fenghuo Mountain of Kekexili, as Ar-Ar candidate standard dating materials. Subsequently, several properties for selecting standard dating material, such as rock structure, component of minerals, content of major elements, Ar-Ar age, were obtained by analyzing the petrological, mineralogical characteristics and chemical components of three kinds of rock samples. Several results can be obtained from outcrop data and lab test as follows:A flat age spectral were obtained indicating the ages of rock is 17.7±0.2 Ma, which is agreement with 99% of energy 39Ar lease, by analyzing Ar-Ar isotope age dating of TB08 Biotite from Granodiorite porphyry in Southern Tibet. Thus, the TB08 Biotitecan be selected as standard material for Ar isotope dating due to its uniform distribution of chemical element in TB08, reliable ages measurement results from Ar-Ar.TB03 sanidine from Yulin Mountain of Gerze, Ngari of northern Tibet can be used as a kind of alternative mineral for dating the rock owing to its high purity, and uniform distribution of Radiogenic Ar ,suitable Ar-Ar dating age. A flat age spectral were obtained indicating the ages of rock is 28.7±0.2 Ma, which is agreement with 98% of energy 39Ar lease.By analyzing Ar-Ar isotope age dating of sanidine in Fenghuo Mountain of Kekexili, a flat age spectral was obtained indicating the ages of rock is 28.81±0.26 Ma corresponding to 99.61% of energy 39Ar lease. The high purity and suitable Ar-Ar dating age, unique Ar isotope system, uniform distribution of chemical component of SK01 sanidine make it be a good alternative dating material.Integrated measurement for three kinds of samples indicated that anidine in Yulin Mountain of Gerze, Ngari of northern Tibet,Biotite in Polan of Southern Tibet and sanidine in Fenghuo Mountain of Kekexili are suitable for standard dating minerals, while thesanidine in Fenghuo Mountain is best and can be used for dating quantitatively. Finally, the sanidine in Fenghuo Mountain was sub-packaged basing on the requirements of National standard materials.Integrated measurement for three kinds of samples indicated that anidine in Yulin Mountain of Gerze, Ngari of northern Tibet,Biotite in Polan of Southern Tibet and sanidine in Fenghuo Mountain of Kekexili are suitable for standard dating minerals, while thesanidine in Fenghuo Mountain is best and can be used for dating quantitatively. Finally, the sanidine in Fenghuo Mountain was sub-packaged basing on the requirements of National standard materials. |
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