CAJ | 학술논문

文章系统研究了老厂矿床的碳酸盐围岩和成矿方解石的碳、氧同位素组成.研究表明,相对于区域地层,矿区碳酸盐岩围岩普遍亏损~(18)O;成矿方解石的碳氧同位素总体上具有明显的正相关性,这些特征表明成矿流体与围岩发生了大规模的水岩反应.文章初步建立了水岩反应的理想模式,根据该模式进一步将成矿方解石划分为矿体中心相和边缘相2组.水岩反应理论模拟表明:总体上成矿流体中的可溶性碳以H_2CO_3为主,中心相成矿流体的δ~(13)C、δ~(18)O值分别为-5.5‰和+4‰,具有典型深部岩浆流体的特征;边缘相成矿流体的δ~(13)C、δ~(18)O值分别为-1.5‰和+4‰,代表了深部岩浆流体与下渗天水共同交代碳酸盐岩围岩后的碳、氧同位素特征.
문장계통연구료로엄광상적탄산염위암화성광방해석적탄、양동위소조성.연구표명,상대우구역지층,광구탄산염암위암보편우손~(18)O;성광방해석적탄양동위소총체상구유명현적정상관성,저사특정표명성광류체여위암발생료대규모적수암반응.문장초보건립료수암반응적이상모식,근거해모식진일보장성광방해석화분위광체중심상화변연상2조.수암반응이론모의표명:총체상성광류체중적가용성탄이H_2CO_3위주,중심상성광류체적δ~(13)C、δ~(18)O치분별위-5.5‰화+4‰,구유전형심부암장류체적특정;변연상성광류체적δ~(13)C、δ~(18)O치분별위-1.5‰화+4‰,대표료심부암장류체여하삼천수공동교대탄산염암위암후적탄、양동위소특정.
Carbon and oxygen isotopic compositions of carbonate host rocks and ore-forming calcite in the Laochang Ag polymetallic deposit of Yunnan Province were studied. The restdts suggest that limestone in the ore district is obviously depleted in ~(18)O relative to the cor-responding strata in this area, and that there exists an obvious positive relation between carbon and oxygen isotopes in ore-forming cal-cites. The C and O isotope evolution suggests that drastic water-rock interaction took place at the ore-forming stage. An ideal water-rock interaction model has been proposed for the C and O isotope evolution. Ore-forming calcite is classified into two groups, with one being the mineralization core phase and the other being the mineralization rim phase. Theoretical simulation of C and O isotope of fluid-rock interaction shows that the dominant dissolved carbon species in the ore-forming fluid are H_2CO_3, and that the δ~(13)C and δ~(18)O of ore-forming hydrothermal fluids of the core phase and the rim phase are - 5.5‰, + 4‰, and - 1.5‰, + 4‰, respectively. The ore-forming hydrothermal fluid of the core phase calcite was derived from magmatic water, whereas the ore-forming hydrothermal fluid of the rim phase calcite was produced by the interaction between the magmatic water and meteorite water and the carbonate host rocks.