Abstract: K-Ar age dating method is facing a serious challenge to its application due to that both Ar loss and Ar excess are widespread found even though it has been undergoing 50 years. In the latest few years of the 20th century, studies on K-Ar geochronology have been pushing on a new step as a sign of method perfected and precision enhanced. High precision and high resolution ⁴⁰Ar/³⁹Ar dating, can use in both micro-area and a single grain, extends dating limit into the historical realm. Applied range of K-Ar geochronology is getting bigger and bigger due to fine analytical techniques while solved geological problems are getting wider and wider.

Key words: K-Ar geochronology, new milestone, laser microproble dating, K-Ar geochronology, new milestone, laser microproble dating

摘要： 已有50年历史的K-Ar定年法，由于过剩Ar和Ar丢失的普遍发现，使其最广泛的应用面临着严重挑战。在20世纪的最后几年，以激光显微探针⁴⁰Ar/³⁹Ar定年方法的完善和精度的提高为标志，把K-Ar年代学研究推向了一个新高度。微区微量高精度高分辨定年，把定年时限扩展到人类历史范畴，精细的分析技术拓宽了年代学的应用范围，使之解决的地质问题更广泛。

关键词: 新的里程碑, 激光显微探针定年, Ar年代学, 新的里程碑, 激光显微探针定年, Ar年代学