新疆萨尔托海高铝铬铁矿中异常矿物群的发现及意义

Discovery and implication of unusual mineral group from Sarthay high-Al chromitites,Xinjiang

在萨尔托海高铝型铬铁矿中发现20余种矿物,包括金刚石、单质铬、自然铁和单质硅等自然元素类;碳化物碳硅石;铁镍、铁镍铬合金等金属合金;方铁矿、金红石、赤铁矿、磁铁矿、钛铁矿、石英和铬尖晶石等氧化物类;方铅矿、闪锌矿、针镍矿、赫硫镍矿和毒砂等硫化物类;镁橄榄石、顽火辉石、透辉石、蛇纹石、锆石和长石等硅酸岩类。这些超高压、强还原性和壳源矿物与俄罗斯极地乌拉尔以及西藏罗布莎铬铁矿可以对比,暗示萨尔托海高铝铬铁矿和高铬铬铁矿一样,可能存在深部地幔成矿阶段。深部地幔矿物以及浅部壳源矿物的发现,暗示萨尔托海铬铁矿的形成可能经历了深部地幔预富集和浅部再造富集成矿两个阶段。

More than 20 mineral species were firstly discovered from Sartohay high-Al chromitites,including： native elements： Cr,diamond,Si,Fe; carbides： Si C; metallic alloys： Fe Cr,Fe Ni Cr; Oxides： wüstite,rutile,ilmenite,hematite,chromite,magnetite,quartz; sulfides： Galena,sphalerite,millerite,heazlewoodite,arsenopyrite; silicates： forsterite,enstatite,diopside,serpentine,zircon,feldspar. These ultra-high pressure,highly-reduced and crustally-derived minerals can totally compare with the minerals from high-Cr chromitites from Luobusa,Tibet and Polar Ural,Russia,which would indicate that Sartohay high-Al chromitites may also have the metallogenic stage in deep mantle like the high-Cr chromitites. The formation of Sartohay high-Al chromitites probably experienced the metallogenic stages both in deep mantle and in shallow upper mantle.