摘要
广东凡口超大型铅锌矿床产于泥盆系台地碳酸盐岩中,矿床成因仍存在较大争议。通过含矿地层岩石以及矿石系统的碳、氧同位素分析研究,发现紫色砂岩的褪色蚀变和碳酸盐岩的白云石化与盆地卤水作用密切相关,褪色蚀变砂岩中的碳酸盐胶结物具有显著低的δ13C和δ18O值,与矿石中碳酸盐矿物相似,白云石化的碳酸盐岩之δ13C和δ18O值介于灰岩与矿石中碳酸盐矿物之间。研究表明,盆地卤水活动与成矿作用密切相关,卤水性质与成矿流体的C、O同位素组成相似,凡口矿床更多地表现出密西西比河谷型(MVT)矿床的特点。卤水沿泥盆系底部碎屑岩运移,引起碎屑岩的褪色蚀变以及上部灰岩的白云石化,促进了铅锌的富集与成矿。
The Fankou lead-zinc deposit occurs in Devonian carbonate platform, and disputations about its genesis still exist. After systemic study of the carbon and oxygen isotope composition of rock and ore of ore-beating strata, it shows that fading alteration in purple sandstone and the phenomenon of dolomitizationin in limestone are closely related with basin brine. The δ^13C and δ^18O value of carbonate cement in fading altered sandstone are similar to carbonate mineral in ores, which is rather low. The δ^13C and δ^18O vaules of dolomitization limestone are between those in ores and carbonate mineral. The research shows that the carbon and oxygen isotope feature of basin brine and ore-forming fluid are analogy, and basin brine is closely related with metallogensis. So in many aspects,the Fankou deposit is more likely to shoe the characters of Mississipi Valley-type. The migration of brine which is alone the bottom of Devonian,lead to fading alteration in clasolite and dolomitizationin of upper limestone, which caused lead and zinc richment and mineralization.
出处
《地质与勘探》
CAS
CSCD
北大核心
2011年第4期642-648,共7页
Geology and Exploration
基金
全国危机矿山找矿专项科研课题"湘南-粤北地区锡钨多金属矿床成矿规律总结研究"(20089927)资助
关键词
地球化学
碳同位素
氧同位素
热卤水
凡口铅锌矿床
geochemistry, carbon isotope, oxygen isotope, hot brine, Fankou Lead-Zinc deposit
