云南个旧打磨山钙质夕卡岩及石榴石的稀土元素地球化学特征

THE GEOCHEMICAL CHARACTERISTICS OF RARE EARTH ELEMENTS IN SKARNS AND THEIR GARNETS FROM DAMOSHAN AREA, GEJIU DISTRICT, YUNNAN PROVINCE

云南个旧打磨山夕卡岩以及其中石榴石的稀土元素组成,从内带到外带,夕卡岩全岩的稀土配分型式类似,∑REE递减,稀土元素呈单向扩散迁移,反映了夕卡岩中的稀土元素主要来自花岗岩体和夕卡岩的扩散交代成因。石榴石的稀土配分型式主要表现为重稀土变化较大,有从重稀土富集型转变为轻稀土富集型的趋势。

The concentration and changing characteristics of rare earth element (REE) in the skarns and garnets, which are the predominant rock-forming minerals of skarns, from Damoshan Area, Gejiu District, Yunnan Province have been studied by means of high precisional neutron activation analytical technique. The fact that the chondrite-normalized REE patterns from the endozonal skarn to the exozonal skarn are similar to each other, with the values of total REE decreasing, reflects that the REE of skarns is derived mainly from granite and exhibits an one-way spreading shift. Probably the scarns are of a diffusional metasomatism genesis. The chondrite-normalized REE patterns of the garnets indicate that the heavy rare earth elements have a great change and a tendency of heavy rare earth elements enrichment converting to light rare earth element enrichment.