论文部分内容阅读
地球大气圈中~(40)Ar/~(36)Ar的现代比值被公认为295.5,在利用K-Ar法测定地球物质年龄时,它是校正大气氩混染量的重要参数。陨石中原始捕获(trapped)的(~(40)Ar/~(36)Ar)_t比值是否和地球大气圈中氩同位素丰度相一致,这个问题不但在地质年龄测定中具有现实意义,而且对探索太阳系的形成和演化也有重要理论价值。近十几年,随着质谱分析技术的提高以及登月计划的实施,国外出现了一批有关月岩中氩同位素原始组分的资料,但至今对陨石中原始氩同位素丰度的报道很少。笔者采用~(40)Ar/~(39)Ar快中子活化技术和约克方程,对吉林陨石雨2号标本进行了原始捕获的(~(40)Ar/~(36)Ar)_t比值进行了测定,并探讨了它的地质意义。
The modern ratio of ~ (40) Ar / ~ (36) Ar in the Earth’s atmosphere is recognized as 295.5, which is an important parameter for correcting the amount of atmospheric argon contamination when determining the age of the Earth by the K-Ar method. Whether the (~ (40) Ar / ~ (36) Ar) _t trapped in the meteorite coincides with the isotopic abundance of argon in the Earth’s atmosphere is not only of practical significance in geological age determination, Exploring the formation and evolution of the solar system also has important theoretical value. In recent ten years, with the improvement of mass spectrometry technology and the implementation of the lunar landing plan, a number of foreign materials about argon isotopes in lunar rocks have appeared in foreign countries. However, the abundance of argon isotopes in meteorites has so far been rarely reported . The ~ (40) Ar / ~ (36) Ar) _t ratio of the original capture of Jilin Meteorite Yuyou No.2 specimen was carried out using ~ (40) Ar / ~ (39) Ar fast neutron activation technique and York equation The determination and discussion of its geological significance.