中文摘要：

沙泉子铁铜矿床是东天山地区赋存于火山岩中的矿床之一。矿体产于底坎尔组玄武岩与英安岩接触部位,在闪长玢岩与围岩接触带上也可见不规则铁矿化。对火山岩的形成时代以及构造地质背景的研究是重建成矿过程的关键。LA-ICP-MS锆石U-Pb定年结果表明,沙泉子铁铜矿区底坎尔组流纹岩和闪长玢岩的206Pb/238U加权平均年龄分别为（321.7±1.7）Ma和（322.2±1.7）Ma,是早石炭世末岩浆活动的产物。元素地球化学和Hf同位素特征表明,底坎尔组火山岩属钙碱性系列,富集轻稀土元素（LREE）和大离子亲石元素（LILE）,亏损高场强元素（Nb、Ta、Ti）,具有岛弧火山岩地球化学特征。基性岩来源于受俯冲板片流体交代的亏损地幔,中性岩为基性岩分离结晶的产物,流纹岩是新生地壳物质部分熔融形成。综合前人研究成果表明,沙泉子铁铜矿床形成于早石炭世末陆缘弧环境,铁矿化不早于322 Ma。

英文摘要：

Located along the Aqishan- Yamansu belt of East Tianshan Mountains, the Shaquanzi Fe- Cu deposit is one of the deposits hosted in Paleozoic volcanic rocks. The deposit occurs in the second and third lithologic memberss of the Dikaner Formation consisting of volcanic rocks intercalated with sedimentary rocks. The iron mineralization also occurs at the contact zone between diorite-porphyrite and wall rocks. The tectonic setting and age of the volcanic rocks are key factors in the reconstruction of the ore- forming process. In this paper, representative samples of Dikaner Formation volcanic rocks and diorite- porphyrite in the Shaquanzi Fe-Cu ore district were analyzed for major and trace elements and zircon U-Pb dating was conducted to investigate the tectonic setting and formation ages of these rocks. LA-ICP-MS analyses of zircons with well-defined oscillatory zoning yielded mean ^206pb/^238U ages of （321.7±1.7） Ma and （322.7 ±1.7） Ma, respectively, indicating that they were formed during late Early Carboniferous. The geochemical data suggest that most of the volcanic rocks belong to talc-alkaline series with the enrichment of LILE, LREE and depletion of Nb, Ta, and Ti, similar to the characteristics of arc volcanic rocks. The zircons from rhyolite and diorite-porphyrite have εHf（t） values of ＋6.28-＋ 15.51 and -0.22-＋ 13.9, respectively. The rhyolites were derived from juvenile crustal materials and basalts, which came from mantle wedge modified by fluids from subducted materials that formed andesite and diorite- porphyrite through crystal fractionation. Regional geology and geochemical evidence indicates that the Dikaner Formation volcanic rocks and diorite-porphyrite were formed simultaneously through island arc magmatism during the late stage of subduction. The Shaquanzi Fe-Cu deposit hosted in the Dikaner Formation were formed after 322 Ma.