新疆喀拉通克铜镍硫化物矿床成因及成矿模式

Genesis and metallogenic model of Cu-Ni sulfide deposits in Kalatongke of Xinjiang

新疆喀拉通克Y1、Y2、Y3主要岩体具有轻稀土元素稍富集,配分曲线相似,近于平行的特征;微量元素,具有明显的Nb、Ta负异常,指示出岩浆源区有壳源物质混染的性质;δ18 O同位素值显示出岩浆经过混染作用;δ34S同位素具有幔源岩浆的特征值。矿床的成矿模式可概括为:来源于亏损地幔的原始岩浆,遭受了地壳俯冲物质的混染经深部熔离成上轻下重的熔体,在构造力的驱动下,经多次上侵-贯入,形成不同的岩相带和稀疏侵染状矿石、致密侵染状矿石以及块状矿石,即目前出露的富含铜镍的喀拉通克镁铁-超镁铁质岩体群。

The Y1, Y2 and Y3 main rock masses in Kalatongke are characterized by slightly enriched LREEs, having similar distribution curves and being nearly parallel with each other. Trace elements with obvious Nb and Ta negative anomalies indicates that the magma source area is featured by hybridization of crust source materials. δ^18O isotope values reveal that the magma underwent hybridization. δ^34S isotope has the charac- teristic value of mantle-derived magma. The metallogenic model of the deposits can be summarized as this： the protomagma from the depleted mantle suffers from hybridization of subducted crust materials and turns into top-light bottom-heavy melt mass through deep liquation, and then through multiple times of uprising- injecting under the drive of tectonic force it forms different petrographic belts as well as sparsely dissemina- ted ores, tightly disseminated ores and massive ores, which are exactly the currently outcropped Cu-Ni-rich Kalatongke mafic-ultramafic rock mass group.