Abstract: Recently,the single-diffusion-domain closure model of Dodson (1973) has been extended to apply to minerals with a discrete distribution of domain size,multi-deffu-sion-domain closure model (Lovera et al.,1989).Because these domains contain a range of closuer temperatures,Lovera et al.(1989) found that a single K-feldspar samples may reveal a broad segment of a cooling history,rather than the single datum usually expected.A study of K-feldspar (FA-2-1) from the Ailao Shan/Red River shear zone,Yunnan,reveals extremely rapid cooling in the interval 20 to 19 Ma using the new model.In consistent with the earlier published analysis involving many biotite samples and a K-feldspar sample collected from Quxu area,southern Tibet.We believe that the two results are related.These two studies underscore the value of using the domain disstribution hypothesis in tectonic studies and presage a revolution in "tectonic geochro-nology".

Key words: Multi-diffusion-domain model, Thermochronology, Ailoshan-Red River shear zone

摘要： 洛弗拉等人(1989)把Dodson(1973)建立的单一扩散域模式扩展成矿物扩散域不连续分布的模式,即多重扩散域模式,与之对应具有某一封闭温度范围,因此利用单个K-长石矿物样品可以揭示更长时间段上的冷却过程。对云南哀牢山-红河剪切带的K-长石样品(FA-2-1)进行⁴⁰Ar/³⁹Ar同位素分析,利用多重扩散域模式,揭示在距今约20～19Ma问该带存在一快速冷却过程,这与西藏南部曲水地区快速抬升的时间是一致的。

关键词: 哀牢山-红河剪切带, 多重扩散域模式, 冷却历史