摘要
长坑矿床金、银矿石的铅同位素组成具有一定的差异，前者的２０６Ｐｂ／２０４Ｐｂ比值变化大，后者较富２０７Ｐｂ／２０８Ｐｂ。金矿石中的铅为普通铅与放射成因铅混合而成的异常铅，银矿石中的铅则可能为三阶段铅混合的产物，且二者均为壳源。方解石的８７Ｓｒ／８６Ｓｒ比值显示锶来自地壳。金、银矿石硫化物的δ３４Ｓ值分别以分散（平均值为负）和较为集中（平均值为正）为特征，并与铅同位素组成之间存在相关关系。结合金、银的矿化分带现象。
The isotopic composition of lead of gold ore is somewhat different from silver ore in Changkeng deposit, i.e., the variation of 206 Pb/ 204 Pb of gold ore is vider while silver ore enrichs 207 Pb and 208 Pb relatively. The lead of gold ore belongs to anomalous lead derived from mixing of common lead with radiogenic lead, and the lead of silver ore probably represents mixture of lead isotopes having undergone three stage evolution. The lead isotope, as well as strontium isotope of calcite, is of crust origin, The δ 34 S values of gold ore are scattered with negative average, while silver ore relatively gathered with positive average. Based on the correlation betwween sulfur and lead isotopic compositions and the zoning of gold and silver ores, a mineralization model for mixing process of fluids with different lead isotopic compositions and oxidizing potentials is presented for Changkeng deposit in this paper.
基金
中国科学院黄金办科研基金
中科院博士点基金
关键词
金矿床
银矿床
铅同位素
锶同位素
硫同位素
isotopes of lead and sulfur anomalous lead of multi stage fluid mixing gold silver deposit Changkeng
