To constrain the evolution of an Early Paleozoic island arc belt abutting the North China Craton (NCC), this study presents new geochronological, geochemical, and Sr–Nd–Hf–O–Pb isotopic data for igneous rocks from the central part of Jilin Province within the southeastern part of the Central Asian Orogenic Belt. The igneous complex in this area hosts both mid-ocean ridge basalt (MORB)- and arc-type rocks that yield zircon ²⁰⁶Pb/²³⁸U ages of ca. 492 and 488–459 Ma, respectively. The MORB-type units in this area include metacumulate gabbros, metadiabases, and metabasalts that have normal MORB (N-MORB)-like compositions with (La/Yb)_N values of 0.29–0.99, Th/Nb values of 0.07–0.52, whole rock ε_Nd(t) values from +4.32 to +7.29, and initial ²⁰⁸Pb/²⁰⁴Pb values of 38.12–38.20. These compositions are indicative of derivation from the depleted asthenospheric mantle. The arc-type igneous rocks consist of amphibolite, epidiorite, and metagabbro with major- and trace-element and isotopic compositions that are similar to island arc tholeiite to calc-alkaline rocks, with (La/Yb)_N values of 1.11–4.26, Th/Nb values of 0.11–2.25, zircon ε_Hf(t) values from +6.03 to +15.30, zircon δ¹⁸O values from +4.32 to +5.1, whole-rock ε_Nd(t) values from +2.09 to +7.25, and initial ²⁰⁸Pb/²⁰⁴Pb values of 38.09–38.11. These compositions are indicative of derivation from partial melting of the hydrous depleted mantle wedge material within an intra-oceanic arc setting. The MORB-type rocks formed within a forearc region of the SSZ ophiolite fragment, whereas the arc-type rocks record the evolution of this region from immature to mature island arc tectono-magmatic settings. Combining these new data with the results of previous research suggests that initial subduction of the Paleo-Asian oceanic plate abutting the northern NCC began during the latest Cambrian.

为约束紧邻华北克拉通 (NCC) 的早古生代岛弧带的演化，本研究提供了吉林省中部火成岩新的年代学、地球化学和 Sr-Nd-Hf-O-Pb 同位素数据在中亚造山带的东南部。该地区的火成岩复合体包含大洋中脊玄武岩 (MORB) 和弧型岩石，产生锆石²⁰⁶ Pb/ ²³⁸ U 年龄 ca。分别为 492 和 488-459 Ma。该地区的 MORB 型单元包括变积辉长岩、偏辉绿岩和偏玄武岩，它们具有正常的 MORB (N-MORB) 类成分，(La/Yb) _N值为 0.29-0.99，Th/Nb 值为 0.07-0.52，全岩 ε _Nd(t) 值从 +4.32 到 +7.29，初始²⁰⁸ Pb/ ²⁰⁴ Pb 值为 38.12–38.20。这些成分表明源自贫化的软流圈地幔。弧型火成岩由角闪岩、绿闪长岩和偏辉长岩组成，主、微量元素和同位素组成与岛弧拉斑玄武岩至钙碱性岩石相似，（La/Yb）_N值为1.11~4.26， Th/Nb 值 0.11–2.25，锆石 ε _Hf (t) 值从 +6.03 到 +15.30，锆石 δ ¹⁸ O 值从 +4.32 到 +5.1，全岩 ε _Nd (t) 值从 +2.09 到 +7.25 , 和初始²⁰⁸ Pb/ ²⁰⁴铅值 38.09–38.11。这些组成表明源自海洋内弧环境中含水的贫化地幔楔材料的部分熔化。MORB 型岩石形成于 SSZ 蛇绿岩碎片的弧前区域，而弧型岩石则记录了该区域从未成熟到成熟的岛弧构造-岩浆环境的演变。将这些新数据与先前研究的结果相结合表明，与华北克拉通北部相邻的古亚洲海洋板块的初始俯冲始于最近的寒武纪。