Laser step-heating ^(40)Ar/^(39)Ar dating on young volcanic rocks  

作　　者：WANG Fei HE Huaiyu ZHU Rixiang YANG Liekun SANG Haiqing WANG Yinglan 

机构地区：[1]Institute of Geology and Geophysics, Chinese Academy of Sciences,Beijing 100029, China

出　　处：《Chinese Science Bulletin》2006年第23期2892-2896,共5页

基　　金：This work was supported by National Natural Science Foundation of China(Grant No.40473031).

摘　　要：An attempt was made to use CO_2 laser step-heating method to date the late Pleistocene basaltic groundmass (DF-2) from Tengchong volcanic field. Among the fourteen heating steps, ten define a good inverse isochron (MSWD = 1.4) with an age of 32.2 ± 7.1 ka (2 σ).The inverse isochron also shows that the initial argon isotopic ratio is 297.1±2.0 (2σ) which is the same as the atmospheric argon at the 2σ error level. Study indicates that it is a useful means to date young volcanic groundmass with low K content by using CO_2 laser step-heating ^(40)Ar/^(39)Ar method.An attempt was made to use CO2 laser step-heating method to date the late Pleistocene basaltic groundmass （DF-2） from Tengchong volcanic field. Among the fourteen heating steps, ten define a good inverse isochron （MSWD = 1.4） with an age of 32.2 ± 7.1 ka （2σ）.The inverse isochron also shows that the initial argon isotopic ratio is 297.1±2.0 （2σ） which is the same as the atmospheric argon at the 2σ error level. Study indicates that it is a useful means to date young volcanic groundmass with low K content by using CO2 laser step-heating ^40Ar/^39Ar method.

关 键 词：二氧化碳激光步式加热 玄武岩基质 岩石学 火山岩 

分 类 号：P588.1[天文地球—岩石学]