The Aqishan-Yamansu belt, Eastern Tianshan is characterized by voluminous Late Paleozoic intermediate–felsic igneous rocks and magmatic–hydrothermal Fe (–Cu) deposits. This study presents zircon U–Pb ages and whole-rock geochemistry of newly identified high-Mg andesitic and dioritic rocks (HMAs and HMDs) within the Hongshanliang copper district in the Aqishan-Yamansu belt, Eastern Tianshan to investigate their petrogenesis and constrain the Carboniferous tectonic setting of the Eastern Tianshan. Zircon U–Pb dating of the HMAs and HMDs yielded ages between 336.9 ± 1.9 Ma and 329.0 ± 4.2 Ma. The HMAs and HMDs show calc-alkaline affinities, and exhibit weak Rb, Ba, U, and Pb enrichment and Nb and Ta depletion, with minor negative Eu anomalies. Moreover, the positive ε_Nd(t) values (+6.4 to +6.6), low Th and (La/Sm)_N contents/ratios, as well as relatively low and variable ε_Hf(t) values (−3.71 to +1.55) indicate that they were probably sourced from a depleted mantle wedge with negligible to minor crustal contamination. They have low Ba/Th ratios (10.8–93.3), minor negative Eu anomalies, high and variable (La/Sm)_N and Th/Yb ratios, which are comparable to the well-known sanukites of the Setouchi volcanic belt, suggesting involvement of sediment-derived magmas during their formation. Integrating published regional mafic–intermediate rocks from the Aqishan-Yamansu belt and this study, we propose that the Hongshanliang high-Mg rocks formed in a continental arc-related setting in the Carboniferous and the belt underwent a sharp tectonic transition event (ca. 330–322 Ma) from the Kangguer oceanic slab steepening to breakoff, corresponding to the Late Carboniferous basin inversion.

东天山阿奇山-雅曼苏带以大量晚古生代中长英质火成岩和岩浆-热液铁(-Cu)矿床为特征。本研究介绍了东天山阿奇山-雅曼苏带红山梁铜矿区新发现的高镁安山岩和闪长岩（HMA 和 HMD）的锆石 U-Pb 年龄和全岩地球化学，以研究它们的成因并限制石炭纪东天山的构造环境。HMA 和 HMD 的锆石 U-Pb 测年得出的年龄介于 336.9 ± 1.9 Ma 和 329.0 ± 4.2 Ma 之间。HMA 和 HMD 显示出钙碱性亲和力，并表现出弱的 Rb、Ba、U 和 Pb 富集以及 Nb 和 Ta 耗尽，具有轻微的负 Eu 异常。此外，正 ε _Nd(t) 值（+6.4 至 +6.6）、低 Th 和 (La/Sm) _N含量/比率，以及相对较低且可变的 ε _Hf (t) 值（-3.71 至 +1.55）表明它们可能是来源于一个耗尽的地幔楔，可以忽略不计到轻微的地壳污染。它们具有低 Ba/Th 比率 (10.8–93.3)、轻微的负 Eu 异常、高且可变的 (La/Sm) _N和 Th/Yb 比值，可与濑户内火山带著名的 sanukites 相媲美，表明在其形成过程中涉及沉积物衍生的岩浆。综合已发表的阿奇山-雅曼苏带区域基性-中质岩和本研究，我们认为红山梁高镁岩形成于石炭纪大陆弧相关环境，该带经历了剧烈的构造转变事件（约330 –322 Ma），来自康古尔大洋板块陡峭到断裂，对应于晚石炭世盆地反转。