摘要
通过对广西凭祥英安岩中方解石的稀土元素含量的测定,结果表明方解石具有与英安岩相似的稀土含量、轻稀土富集、无铈异常和具有明显的铕负异常等特点。结合英安岩的矿物组成和蚀变特征及其方解石的碳氧同位素组成,推测方解石是英安岩蚀变的产物,其稀土元素主要来源于英安岩,英安岩中黑云母蚀变形成绿泥石及方解石优先结合轻稀土是方解石相对英安岩富集轻稀土的主要原因,而方解石相对英安岩较弱的铕负异常主要是英安岩中斜长石优先蚀变的结果。
Rare earth elements （REE） in calcite in dactie of Pingxiang, Guangxi, were analyzed. The results showed that both dacite and calcite have some similar characteristics, such as similar REE concentrations, LREE enrichment, no Ce anomaly, and obvious negative Eu anomaly. Combined mineralogy and alteration of dacite with carbon and oxygen isotopes of calcite, it is inferred that calcite in dacite is altered from dacite reaction with oceanic water and REE is mainly derived from dacite. The reason of more LREE enriched in calcite than dacite is that biotite altered to chlorite and that LREE are preferred to be accommodated in calcite. The relatively weak Eu negative anomaly in calcite is mainly attributed to feldspar alteration in dacite of Pingxiang.
出处
《地球与环境》
CAS
CSCD
北大核心
2007年第1期51-56,共6页
Earth and Environment
关键词
英安岩
方解石
稀土元素
地球化学
凭祥
dacite
calcite
rare earth element
geochemistry
Pingxiang
