Abstract The Aqishan-Yamansu belt in the Eastern Tianshan (NW China) contains many intermediate to felsic intrusive rocks and spatially and temporally associated Fe (-Cu) deposits. Zircon U-Pb dating of the Bailingshan granitoids, including diorite enclaves (in granodiorite), diorite, monzogranite and granodiorite, and andesitic tuff from the Shuanglong Fe-Cu deposit area yielded ages of 329.3 ± 2.1 Ma, 323.4 ± 2.6 Ma, 313.0 ± 2.0 Ma, 307.5 ± 1.7 Ma and 318.0 ± 2.0 Ma, respectively. These new ages, in combination with published data can be used to subdivide magmatism of the Bailingshan intrusive complex into three phases at ca. 329–323 Ma, ca. 318–313 Ma and ca. 308–297 Ma. Of the analyzed rocks of this study, the Shuanglong diorite enclave, diorite and andesitic tuff show calc-alkaline affinities, exhibiting LILE enrichment and HFSE depletion, with negative Nb and Ta anomalies. They have high MgO contents and Mg# values, with depleted eHf(t) and positive eNd(t) values, similar crustal-derived Nb/Ta and Y/Nb ratios, low Th/Yb and Th/Nb, and high Ba/La ratios, which are consistent with them being sourced from a depleted mantle wedge metasomatized by slab-derived fluids and crustal contamination. However, the monzogranite and granodiorite are metaluminous with characteristics of low- to high-K calc-alkaline I-type granites. The granitic rocks are enriched in LILE, depleted in HFSE and have significant Eu anomalies, with high Y contents and low Sr/Y ratios, resembling typical of normal arc magmas. Depleted eHf(t) and positive eNd(t) values with corresponding young TDMC ages of zircons, as well as Nb/Ta, Y/Nb, Th/U and La/Yb ratios suggest that the granitic rocks were probably formed by re-melting of juvenile lower crust or pre-existing mantle-derived mafic–intermediate igneous rocks. Integrating published data, we conclude that the Bailingshan granitoids (excluding the Shuanglong diorite and diorite enclave) were derived from re-melting of juvenile lower crust and mantle-derived mafic–intermediate igneous rocks, with mantle components playing a more prominent role in the formation of the younger and more felsic rocks. A comprehensive review, including our new data, suggests that the Aqishan-Yamansu belt formed as a fore-arc basin during the Carboniferous (ca. 350–300 Ma) when the Kangguer oceanic slab subducted beneath the Yili-Central Tianshan block. The ongoing southward subduction of the slab resulted in the closure of the Aqishan-Yamansu fore-arc basin (ca. 320–300 Ma), due to slab steepening and rollback followed by slab breakoff and rebound. During the Aqishan-Yamansu fore-arc basin inversion, the main phase of the Bailingshan granitoids emplaced in the Aqishan-Yamansu belt, accompanied by contemporary Fe and Fe-Cu mineralization.

中文翻译：

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东天山阿奇山-雅满苏带晚古生代岩浆作用与成矿作用: 来自白灵山侵入杂岩的制约

摘要 东天山阿奇山-雅曼苏带中含有许多中长英质侵入岩和时空伴生的铁（-铜）矿床。双龙铁铜矿区的白岭山花岗岩，包括闪长岩飞地（在花岗闪长岩中）、闪长岩、二长花岗岩和花岗闪长岩以及安山凝灰岩的锆石U-Pb定年年龄为329.3±2.1 Ma，323.4±310.分别为 2.0 Ma、307.5 ± 1.7 Ma 和 318.0 ± 2.0 Ma。这些新时代结合已发表的数据可用于将白岭山侵入杂岩体的岩浆活动细分为约 329-323 马，约。318-313 马和约。308-297 马。在本研究分析的岩石中，双龙闪长岩飞地、闪长岩和安山凝灰岩显示钙碱性亲和性，表现出 LILE 富集和 HFSE 耗竭，具有负的 Nb 和 Ta 异常。它们具有高 MgO 含量和 Mg# 值，具有耗尽的 eHf(t) 和正 eNd(t) 值，类似地壳衍生的 Nb/Ta 和 Y/Nb 比率，低 Th/Yb 和 Th/Nb，以及高 Ba/ La 比率，这与它们来自被板片衍生流体和地壳污染交代的耗尽地幔楔一致。但二长花岗岩和花岗闪长岩为金属铝质，具有低至高K钙碱性I型花岗岩的特征。花岗岩中LILE富集，HFSE贫化，Eu异常显着，Y含量高，Sr/Y比低，类似于典型的弧形岩浆。耗尽的 eHf(t) 和正 eNd(t) 值与相应的年轻 TDMC 年龄的锆石，以及 Nb/Ta、Y/Nb、Th/U 和 La/Yb 比值表明花岗岩可能是由新生的下地壳或先前存在的地幔衍生基性-中间火成岩重新熔化形成的。综合已发表的资料，我们得出结论，白岭山花岗岩类（不包括双龙闪长岩和闪长岩飞地）来源于幼年下地壳和幔源基性-中质火成岩的重熔，其中地幔组分在形成过程中的作用更为突出更年轻和更长英质岩石。包括我们的新数据在内的综合回顾表明，在石炭纪（约 350-300 Ma）期间，当康古尔大洋板块俯冲到伊犁-中天山地块下方时，阿奇山-雅曼苏带形成为弧前盆地。由于板块陡峭和回滚，随后板块断裂和反弹，板块持续向南俯冲导致阿奇山-雅曼苏前弧盆地关闭（约 320-300 Ma）。在阿奇山-雅曼苏弧前盆地反转期间，白岭山花岗岩主相就位于阿奇山-雅曼苏带，同时伴随着当代铁矿和铁铜矿化。