陕西岚皋浦家沟铜矿床中硒矿物的赋存状态研究

笔者在对陕西省岚皋县浦家沟铜矿床进行矿物学研究的过程中,发现该矿床中存在硒铜银矿、硒铅矿等2种硒的独立矿物.利用电子探针分析结果计算得:硒铜银矿化学分子式为(Ag0.95~1.00 Cu0.95~1.00 Fe0.02~0.03)1.97~1.99(Se0.72~0.76 S0.22~0.27 Te0.01)1,硒铅矿化学分子式为(Pb0.96~0.98 Fe0.01~0.03 Cu0.01~0.03)1.00~1.01(Se0.86~0.93 S0.07~0.14)1.其中硒铜银矿分布于表生辉铜矿内部或边缘,与之关系密切;硒铅矿则主要分布于黄铁矿与黄铜矿的接触部位或黄铁矿内部,与方铅矿、闪锌矿等共生.硒铅矿作为一种中低温热液矿物,它的出现暗示浦家沟铜矿经历过中低温热液阶段;硒铜银矿由后期含Ag+、Cu+溶液与次生辉铜矿反应形成的,它的存在暗示该矿床经历过后期成矿作用的叠加改造.

Status of selenium minerals in the Pujiagou copper deposit in Langao county,Shaanxi province

In the study of mineralogical characteristics of Pujiagou copper deposit in Langao county, Shaanxi Province, the author discovered two selenium-bearing minerals:eucairite and clausthalite. The electron microprobe analyses showed that the chemical formula for eucairite was ( Ag0 . 95 ~ 1 . 00 Cu0 . 95 ~ 1 . 00 Fe0 . 02 ~ 0 . 03 ) 1 . 97 ~ 1 . 99 ( Se0 . 72 ~ 0 . 76 S0 . 22 ~ 0 . 27 Te0 . 01 ) 1 , and the chemical formula for clausthalite was ( Pb0 . 96 ~ 0 . 98 Fe0 . 01 ~ 0 . 03 Cu0 . 01 ~ 0 . 03 ) 1 . 00 ~ 1 . 01 ( Se0 . 86 ~ 0 . 93 S0 . 07 ~ 0 . 14 ) 1 . Eucairite was distributed inside or on the edge of chalcocite. Clausthalite was distributed inside pyrite or on the border of pyrite and chalcopyrite with galena and sphalerite. Clausthalite was generally formed in moderate-lower temperature hydrothermal system, so its existence inferred that Pujiagou copper deposit had experienced moderate-lower temperature hydrothermal stage. Eucairite was formed by late ore-bearing fluid that containing Ag+ and Cu2+ reacting with chalcocite, and its existence implied that this deposit had underwent late superimposed mineralization.