绿石沟岩体位于东准噶尔琼河坝矿集区,向东侵入到绿石沟铜矿赋矿围岩中泥盆统北塔山组火山岩中.LA-ICP-MS锆石U-Pb测年显示该岩体形成于354±1 Ma,为早石炭世.其主要岩石类型为石英二长岩,含有大量的基性微粒包体,具有较高的硅、钙、钾含量(SiO2=62.31％ ～65.31％,CaO=3.71％ ～4.89％,K2O=2.85％～3.54％),属高钾钙碱性系列.铝含量较高(Al2O3=15.44％～16.29％),属准铝质(A/CNK=0.93～0.99,A/NK=1.68～1.96)Ⅰ型花岗岩.稀土元素总量较低(∑REE=90.82×10-6～111.36×10-6),轻稀土元素相对富集,Eu呈弱的负异常(δEu=0.68～0.87).富集大离子亲石元素(K、Rb、Ba、Sr等),亏损高场强元素(Nb、Ta、P、Ti等),具有高Ba(758×10-6～1 113×10-6)、Sr(401.8×10-6～512.5×10-6)含量和高的(La/Yb)N、Sr/Y值,显示出高Ba-Sr花岗岩的特征,应是幔源基性岩浆与壳源岩浆混合的产物,可能形成于俯冲环境向造山后环境的构造转换阶段.%The Lüishigou pluton is located in the Qiongheba ore concentration area in East Junggar.This pluton intruded into the host rock of the Lüshigou copper deposit.LA-ICP-MS U-Pb dating of zircons from this pluton yielded an early Carboniferous age of 354 ± 1 Ma.The main rock type of the pluton is quartz-monzonite withmany mafic-ultral marie enclaves inside.These quartz-monzonites have high SiO2 (62.31％ ～65.31％),Al2O3 (15.44％ ～16.29％),CaO (3.71％ ～4.89％) and K2O (2.85％ 3.54％) contents,exhibiting high-K calcalkaline and metaluminous characteristics (A/CNK =0.93～0.99,A/NK =1.68～1.96),and belonging to Ⅰ-type granite.The total REE values of them are low (90.82 × 10-6～111.36 × 10-6) with relative enrichment of LREE and Eu negative anomaly (δEu=0.68～0.87).The primitive mantle normalized trace dement patterns are characterized by the enrichment of the LILE (K,Rb,Ba,Sr) and depletion of the HFSE (Nb,Ta,P,Ti).The quartz-monzonitehas high Ba (758 × 10-6 ～ 1 113 × 10-6),Sr (401.8 × 10-6 ～ 512.5 × 10-6) values with high (La,/Yb)N,Sr/Y ratios,distinct Nb,Ta and Ti depletion,and are comprehensively called high Ba-Sr granitoid.These characters indicate that the Lüshigou pluton was probably formed by the magma-mixing of the mantle-derived mafic magma and crustal partial melting magma during the tectonic transition period from subduction to post-orogenic setting in the late Paleozoic.
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