西准噶尔塔斯阔腊岩体地球化学特征及成因

Geochemical Characteristics and Their Genetic Significance of the Tasikuola Intrusion in West Junggar, Xinjiang

新疆西准噶尔塔斯阔腊岩体岩性主要为花岗闪长岩,岩石富TiO_2、Fe_2O_3、FeO和K_2O,贫CaO和P_2O_5,为准铝—弱过铝质、高钾钙碱性系列;稀土元素总含量(ΣREE)中等,轻稀土(LREE)相对富集,岩浆作用过程中轻、重稀土元素分馏作用较明显,具Eu弱亏损。多种主量元素和稀土元素地球化学特征表明:岩石成因应为壳幔同熔型花岗岩,形成的构造背景为火山岛弧环境;该区具有寻找中-酸性侵入体接触带型金矿的控矿条件。

The Tasikuola intrusion in west Junggar of Xinjiang is a granodiorite intrusion which is rich in TiO2, Fe2O3, FeO, K2O, and depleted in CaO and P2O5, belonging to the rich-K calc-alkaline and metaluminum to weak peraluminous series. The EREE is medium and LREE is relative enrichment. The fractionation between HREE and LREE in magmatic processes was obvious with relatively weak negative Eu anomaly. All these indicate that the rock should be crust-mantle-derived syntectic granitoid, and was emplaced in volcanic island arc environment. This area has the ore-controlling conditions for gold type in mid-acid intrusive contact zone.