云南兰坪白秧坪铜钴多金属矿集区矿石中石英的^(40)Ar-^(39)Ar年龄  

^(40)Ar-^(39)Ar DATING OF ORE QUARTZ FROM THE BAIYANGPING Cu-Co POLYMETALLIC MINERALIZED CONCENTRATION AREA,LANPING,YUNNAN

作　　者：何明勤[1] 刘家军[2] 李朝阳[1] 李志明[1] 刘玉平[1] 杨爱平 桑海清[4] 

机构地区：[1]中国科学院地球化学研究所矿床地球化学重点研究实验室,贵阳550002 [2]中国地质大学,北京100083 [3]云南省地质矿产局第三地质大队,云南大理671000 [4]中国科学院地质与地球物理研究所,北京100029

出　　处：《地质科学》2006年第4期688-693,共6页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：973国家重点基础研究发展规划项目(编号:G1999043208)和;云南省教育厅科学研究基金项目(编号:0142104)资助。

摘　　要：云南兰坪白秧坪铜钴多金属矿集区矿石中石英的40Ar-39Ar快中子活化年龄谱呈马鞍形,坪年龄为56.53±0.43Ma,最小视年龄为55.52±1.78Ma,等时线年龄为55.90±0.29Ma,三者在误差范围内一致(1σ)。40Ar/36Ar初始值为294.7±1.14,与尼尔值(295.5±5)十分接近,坪年龄和等时线年龄均可作为石英的形成时代。因此,55.90~56.53Ma(喜马拉雅早期)代表了矿床的成矿年龄。^40Ar-^39Ar fast neutron activation age spectrum of quartz in ore collected from the Baiyangping Cu-Co polymetallic mineralized concentration area in Lanping, Yunnan, showed a characteristic of saddle shape. The obtained plateau age, minimum appearance age and isochron age of the spectra were 56.53±0.43 Ma,55.52 ± 1.78 Ma and 55.90 ±0.29 Ma respectively, all of three ages being identical within 1 σ uncertainties. Both of the plateau and isochron ages could be regarded as the quartz＇s forming time, since the given ^40Ar-^39Ar initial value of 294.7 ±1.14 was very close to Nier＇s value （295.5± 5）, namely, the age of 55.90 ± 56.53 Ma （Early Himalayan period） represented the ore deposits＇ forming age.

关 键 词：^40AR-^39AR年龄 喜马拉雅早期 铜钴多金属矿集区 滇西兰坪 

分 类 号：P597[天文地球—地球化学]