阿克图约克花岗闪长岩富黑云母,具较高SiO2(61.53％～67.01％),低里特曼指数(1.8～2.25),富钠贫钾,A/CNK小于1,稀土元素总量中等(∑REE=64.64×10-6～76.12×10-6),弱Eu亏损,富集大离子亲石元素(Th,K,Ba,LREE),亏损HREE和高场强元素(Ti,Ta,Nb,P),Nb/Ta小于1等特征.该岩体为钙碱性系列准铝质花岗闪长岩,并具Ⅰ型花岗岩特征.岩体LA-ICP-MS锆石U-Pb年龄为(329.7±1.9) Ma,早于苏云河含矿岩体,为早石炭世洋壳俯冲背景下的火山弧花岗岩,暗示洋壳闭合时限晚于(329.7士1.9) Ma.%The geological and geochemical characteristics of Aketuyueke granodiorites are rich in biotite,high SiO2 (61.53％～67.01％),low rittmann index(1.8～2.25),rich sodium and poor potassium,A/CNK＜1.Granodiorites have medium REE(∑ REE=64.64 × 10-6～76.12 × 10-6) with enrichment of LREE and LILE(Th,K,Ba),depletion HREE and HFSE(Ti,Ta,Nb,P),and the ratios of Nb with Ta are less than 1.The rocks belong to calc-alkaline metaluminous granodiorites,which synthetically display the characteristics of I-type granite.The U-Pb zircon LA-ICP-MS age of Aketuyueke granodiorites is (329.7±1.9) Ma,earlier than Suyunhe ore-bearing granite.Aketuyueke granodiorites are volcanic arc granite under the background of oceanic subduction,indicating the time of oceanic basin closing is later than (329.7±1.9) Ma.
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