用激光微区Ar-Ar定年技术研究高压白云母中过剩氩成因

观察苏鲁-大别地区超高压变质岩块高压白云母中过剩氩的赋存和岩性之间的相关关系、单帕０自颇钢泄ｋ驳姆植继卣骱涂笪颩g/Fe比值、正4价Si含量、Na/K比值以及和其它元素洹⒑涂笪锵晕⒔峁怪涞南喙毓叵担匀范üｋ苍诟哐拱自颇钢懈炒娴闹饕刂埔蛩兀荽耍教衷诔哐贡渲侍跫鹿ｋ驳睦丛础⒗┥⑿形约傲魈宥怨ｋ苍艘频挠跋臁

In recent years, the study of excess argon genesis in high-pressure white micas is a hot topic in the field of isotope geochronology. In this research project, we have got a series conclusions: (1) there is no excess argon in the high-pressure white micas being in the orthogneiss; (2) The distribution of excess argon in eclogite is positive correlative with the ratio of Mg/(Mg+Fe), but negative with the ratio of Na/(K+Na); (3) The in-situ analyses by using the method of laser probe 39Ar-40Ar show that the age radius from central to margin in a single grain of high-pressure white mica in eclogite; (4) There is no any evidence to prove that the excess argon in eclogite comes from fluid; (5) The excess argon in eclogite inherited from primitive rock during high-ultra high pressure metamorphism; (6) There is no excess argon in the eclogite when its surrounding rock is carbonate.