Research&Development Of Cenozoic Sanidine SK01 As A National Standard Reference Materials For ³⁹Ar-⁴⁰Ar Dating

The 39Ar-40Ar dating is widely used in geochronology,deposit chronology,orogenic belt chronology and the young geological system chronology.Reference material is not only essential forobtaining39Ar-40Ar isotopic age,but also the main factor to affect the quality of the 39Ar-40Ardating.In order to yield high-precision results of39Ar-40Ar dating technique,all age data depend on accurate ages of National Standard Reference Materials that were irradiated together with unknown samples in a neutron reactor.In order to eventually obtain accurate 39Ar-40Ar age,it's necessary to develop reference materials with different age values.In this study,Sanidine SK01 as Cenozoic reference material of 39Ar-40Ar dating method,was separated from hypabyssal quartz porphyry in Fenghuo Mountain of the Kekexili.As a method of experimental techniques,indoor research met the requirements of the national first-grade technical specification for standard materials as JJG1006-1994.The main research include five aspects:the preparation of Sanidine SKO1,the homogeneity testsof Sanidine SK01,the stability testsof Sanidine SK01,the analysis of Sanidine SK01,statistical method of data treatment and obtain certified value.Several results can be obtained as follows:(1)Prepared more than 1000g Sanidine SK01 single minerals in high quality;(2)The homogeneity tests indicate Cenozoic sanidine SK01 with a good homogeneity,which would provide forvalue testing of 39Ar-40Ar age;(3)The stability tests indicate Cenozoic sanidine SK01 with a good stability,which is suitable for long-term preservation and use;(4)The 39Ar-40Ar age of Sanidine SK01 is27.60±0.46Ma(2?).