摘要
朝山金矿床位于安徽铜陵狮子山矿田 ,属于矽卡岩型金矿床 ,侵入岩体为白芒山辉石二长闪长岩体。成矿过程包括矽卡岩阶段、石英_硫化物阶段和碳酸盐阶段 3个主要成矿阶段。文章通过对朝山金矿床的氢、氧、碳、硫、硅同位素组成和稀土元素地球化学特征的研究 ,探讨成矿溶液中水、碳、硅和硫的来源以及成矿溶液的演化问题。研究表明 ,成矿热液早期以岩浆热液为主 ,随着成矿过程的进行 ,加入的大气降水比重越来越大 ,到晚期可能主要以大气降水为主。该矿床矿石中方解石的碳、氧同位素组成与矿区大理岩的碳、氧同位素组成明显不同 ,其δ13CV_PDB、δ18OV_SMOW值分别为 - 4 .5～ - 5 .3‰、13.9～ 14 .0‰ ,与岩浆作用形成的CO2 的碳、氧同位素组成一致 ,表明矿石中方解石的碳、氧来源于岩浆作用。硅和硫具深部岩浆或岩浆热液来源的特点。
The Chaoshan gold deposit, a skarn type deposit recently discovered in the Shizishan orefield of Tongling, Anhui Province, is directly related to the pyroxene_monzodiorite. Pyroxene_diorite is the enclosing rock. The formation of the ore deposit might be divided into three ore_forming stages, i.e., skarn stage, quartz_sulfide stage and carbonate stage. A lot of research work has been done in such aspects as mineral deposit, mineralogy and tectonics. Based on the work done, this paper deals mainly with hydrogen, oxygen, carbon, sulfur, silicon isotopic compositions and REE geochemistry of the Chanshao gold deposit. The results show that the ore_forming solution at the initial stage was dominated by magmatic water, whereas the meteoric water gradually entered the mineralizing system and played an important role in the ore_forming processes of later stages. The C and O isotopic compositions of calcites in ores are different from those of marble in the orefield. The C and O isotopic compositions range from -4.5～-5.3‰ and 13.9～14.0‰, respectively, which are similar to the C and O isotopic compositions of magmatism. Therefore, C and O in ores might have come from magmatism. Siliconand sulfur isotopes are quite similar to those in magma or magmatic hydrothermal solutions. The REE chondrite normalized model is in a right_dipping form.
出处
《矿床地质》
CAS
CSCD
北大核心
2004年第3期365-374,共10页
Mineral Deposits
基金
国土资源部科技司专项研究计划 (编号 :2 0 0 10 10 3 )
国土资源部重点科技项目 (编号 :2 0 0 10 2 0 9)联合资助
关键词
地球化学
稳定同位素
稀土元素
朝山金矿床
安徽铜陵
geochemistry, stable isotope, REE, Chaoshan gold deposit, Tongling in Anhui Province
