投稿时间：2023-05-09
修订日期：2023-11-01
网络发布日期：2023-12-29
中文摘要:新疆西天山北缘的博罗科努晚古生代岛弧带出露大量中酸性侵入体，并发育一系列斑岩-矽卡岩型铁铜多金属矿床。文章对该岛弧带中部阔库确科矽卡岩型铁铜矿床成矿岩体中的锆石开展了微量元素地球化学研究，查明了锆石成因、形成物理化学条件及其对成矿的启示意义等。数据显示，与成矿密切相关的正长花岗岩和闪长岩中锆石均表现为重稀土元素富集、轻稀土元素亏损，正长花岗岩中锆石的∑REE介于（627~1625）×10-6，闪长岩中锆石的∑REE介于（345~1439）×10-6。锆石Ti温度计显示正长花岗岩锆石的结晶温度集中在598~810℃；闪长岩锆石结晶温度为651~932℃，正长花岗岩的氧逸度（ΔFMQ+4.25）高于闪长岩（ΔFMQ-1.01）。成矿岩体锆石均形成于封闭的岩浆体系中，主要为岩浆锆石，少量闪长岩中的锆石可能在岩浆晚期遭受了富集轻稀土元素的热液改造。锆石形成构造背景属于大陆岛弧环境。成矿岩体锆石的Ce4+/Ce3+值明显高于区域内不成矿岩体的Ce4+/Ce3+值，其中正长花岗岩锆石中更高的Ce4+/Ce3+值表明，阔库确科矿区内志留系与正长花岗岩发生接触交代形成的矽卡岩中可能有更大的Cu成矿潜力。
Abstract:The Late Paleozoic Boluokenu island arc belt, located at the northern margin of the West Tianshan Mountain, Xinjiang Autonomous Region, China, hosts abundant mineral resources and intermediate-acid intrusions. In this paper, the trace element geochemistry of zircons from ore related intrusions in the Kuokuqueke skarn type iron-copper deposit in the central part of the island arc belt has been studied, and the genesis, physical and chemical conditions of zircon formation and its implications for mineralization have been identified. The data shows that zircon in syenogranite and diorite closely related to mineralization is enriched in heavy rare earth elements and depleted in light rare earth elements. The ∑REE of zircon in syenogranite is (627~1625)×10-6, the ∑REE of zircon in diorite is (345~1439)×10-6. The Ti zircon thermometer shows that the crystallization temperature of zircon in syenogranite is concentrated in range of 598~810℃, and the crystallization temperature of zircon in diorite is concentrated in range of 651~932℃, and the oxygen fugacity of syenogranite (ΔFMQ +4.25) is significantly higher than diorite (ΔFMQ -1.01). The zircons of the ore-forming rocks were formed in a closed magmatic system, mainly magmatic zircons. A small amount of zircons in diorite may have been transformed by LREE enriched hydrothermal in the late magmatic period. The Ce4+/Ce3+values of zircons from ore-forming rocks are significantly higher than those from non ore-forming rocks in the region. Among them, the higher Ce4+/Ce3+values in zircons from syenogranite indicate that there may be greater Cu mineralization potential in the skarns formed by contact metasomatism between the Silurian strata and syenogranite in the Kuokuqueke ore district.
keywords:zircon trace elements oxygen fugacity ore-forming intrusions Boluokenu island arc belt western Tianshan Mountain
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基金项目:本文得到国家自然科学基金项目（编号：42202094、42130804）资助
引用文本：
顾枫华,章永梅,彭义伟,王佳琳.2023.新疆西天山阔库确科铁铜矿区成矿岩体锆石微量元素地球化学特征及其地质意义[J].矿床地质,42(6):1159~1174GU FengHua,ZHANG YongMei,PENG YiWei,WANG JiaLin.2023.Zircon trace element geochemical characteristics and geological significance of ore forming rocks in Kuokuqueke iron copper ore district, western Tianshan, Xinjiang[J].Mineral Deposits42(6):1159~1174
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