新疆阿尔泰凯勒克赛依铁矿地质特征、锆石LA MC ICP MS U Pb年龄及其意义

凯勒克赛依铁矿床是新疆阿尔泰唯一的小型镜铁矿床，赋存于一套变质火山-沉积岩系中，近矿围岩为白云母石英片岩，矿体呈层状，与地层产状一致，矿石具有块状、条带状、条纹状构造，矿石中金属矿物主要为镜铁矿(TFeO=87349%~88988%，TiO2=0~1042%，Al2O3=0036%~0256%)，矿化具有沉积特征。近矿围岩镜铁矿白云母石英片岩锆石LA MC ICP MS U Pb谐和年龄为(3756 ± 06)Ma，限定成矿时代在376 Ma左右，即中泥盆世成矿，是阿尔泰为数不多的中泥盆世成矿作用的产物。同时也厘定含矿的变质火山-沉积岩系属中—晚泥盆世阿勒泰镇组，不是前人认为的早泥盆世康布铁堡组。

Geological Characteristics,Zircon LA-MC-ICP-MS U-Pb Age of Kailekesaiyi Iron Deposit in Altay,Xinjiang,and Their Geological Implications

Kailekesaiyi iron deposit, the unique small specularite deposit in Altay, Xinjiang, occurs in a sequence of metamorphic volcanic sedimentary rocks. The wall rock is muscovite quartz schist, and the orebodies are stratiform and in accordance with the stratigraphic occurrence. The ores occur as massive, banded, and striped structures. Ore minerals are dominated by specularite (TFeO=87349%-88988%，TiO2=0-1042%，Al2O3=0036%-0256%) with sedimentary characteristics. Zircons from the specularite muscovite quartz schist yield a LA MC ICP MS U Pb concordant age of (3756 ± 06) Ma, and constrained the ore forming age to the Middle Devonian (ca376 Ma), suggesting that this deposit is one product of the few Middle Devonian mineralization in Altay. Meanwhile, the ore bearing metamorphic volcanic sedimentary rocks are dated to the Middle Late Devonian Altay Formation, rather than the Early Devonian Kangbutiebao Formation which is considered by the previous scholars.