我国夕卡岩矿床中的辉石和似辉石特征及其与金属矿化的关系

根据我国３７个夕卡岩矿床中辉石和似辉石的成分和共生矿物特征等的综合研究分析，指出不同金属矿化夕卡岩中的辉石、似辉石类型和成分特征各不相同，因而作为鉴别夕卡岩含矿性的翻来覆去矿的地球化学标志，岩浆期镁夕卡岩中的辉石为铝透辉石，可伴生磁铁矿化；岩浆期后镁夕卡岩中的为较纯的透辉石，可能伴生Ｆｅ、Ｃｕ、Ｍｏ、Ｓｎ、Ａｕ等矿化；钙夕卡岩中的辉石主要为透辉石，而似辉石成分多为硅灰石，随着辉石中钙铁辉石和钙鳃辉

Characteristics of pyroxenes and pyroxenoids in skarn deposits of China and their relationship with metallization

Dased on chemical analyses and mineralogical characteristics of 324 pyroxene and pyroxenoid samples from 37 major skarn deposits in China, it can be seen that pyroxenes and pyroxenoids in different ore-bearing skarns are of definitely different types and compositional characteristics, which can be used as important mineralogical and geochemical indicators for identification of skarn mineralizations. Pyroxene in the magmatic magmatic skarn is generally aluminodiopside probably subjected to magnetitization. Pyroxene in the postmagmatic magnesian skarn is relatively pure diopside, associated sometimes with Fe, Cu, Mo, Sn, Au mineralizations. Pyroxenes in the calcic skarn are of diopside-hedenbergite series, while pyroxenoid is wollastonite. The constituents of the coexisting pyroxene-garnet pair can not only reflect the aciclity and oxygen fugacity conditions for the formation of skarns , but also indicate types of associatcd mincralizations. With the incrcaxsc of hcdcnbcrgitc moleculcs in pyroxcncs and the decrease of andradite molecules in garnets, the accompaning mineralizations also vary regularly, being in order of Fe, Cu, Au-*Mo W Sn, Pyroxenes in the Pb, Zn (Ag) -bearing manganoan skarns are manganohedenbergite and johannsenite, whereas associated pyroxenoids are bustamite, thodonite and pyroxmangite. Pyroxenes in the U, Th, Nb-bearing alkaline skarn are aegirine and aegirine-augite, associated with lois of alkaline metasomatic minerals such as orthoclase, arfvedsonite, eckermannitc, sodic tremolite and ferriferous phlogopite. Mn/Fe and Mg/Fe ratios of pyroxenes in each ore-bearing skarn are relatively stable and hence may be used to indicate the type of metallization.