新疆尾亚钒钛磁铁矿夕卡岩捕虏体的地质特征

尾亚矿床是东天山地区规模最大的钒钛磁铁矿矿床,其含矿岩体中新发现了夕卡岩捕虏体。尾亚夕卡岩捕虏体具有核-边二元结构,其核部为外夕卡岩,其边部为内夕卡岩。尾亚外夕卡岩以它形结构和含有镁橄榄石为特征,内夕卡岩则以半自形粒状结构和含有高钙契尔马克分子单斜辉石为特征。尾亚夕卡岩捕虏体的发现表明其含矿岩体母岩浆在运移和就位过程中同化混染了碳酸盐岩地层。碳酸盐岩同化混染作用改变了尾亚含矿岩体Sr-Nd-O同位素组成,导致了斜长石的大量结晶堆积,以及尾亚钒钛磁铁矿矿床的形成。

Geological characteristics of xenolith skarns in Weiya Fe-Ti-V oxide deposit, Xinjiang

Weiya Fe-Ti-V oxide deposit is the largest one in eastern Tianshan, and xenolith skarns is newly discovered in its ore-bearing intrusion. Weiya thenolith skarns have been classed as exoskarns in the core, and endoskarns occur as reaction rim. Weiya exoskarns are characterized by xenomorphic textures and forsterite, while endoskarns are characterized by a hypidiomorphic texture and Ca-Tschermak-rich clinopyroxene. The discovery of Weiya xenolith skarns suggests that the parental magma of the Weiya ore-bearing intrusion had contaminated carbonate wallrocks during migration and emplacement. Carbonate rocks contamination changed Sr-Nd-O isotope compositions of the Weiya ore-bearing intrusion, induced plagioclase crystallized abundantly and the formation of the Weiya Fe-Ti-V oxide deposit.