Neoarchean granitic rocks are important components of Precambrian cratons, and their petrogenesis can provide constraints for understanding the evolution of continental crust. The Neoarchean potassic granites are widely distributed in southern Jilin Province, which is located in the northeastern part of the North China Craton. Newly obtained field geology observations and petrological, geochemical and geochronological data reveal that the Jiapigou potassic granitic complex is mainly composed of biotite granitic gneiss and medium- to coarse-grained granite. All the granitic gneisses and granites are high-K calcium–alkaline to shoshonite, metaluminous to peraluminous (A/CNK = 0.95–1.13; molar Al₂O₃/(CaO + Na₂O + K₂O)), enriched in LILEs and LREEs with strongly fractionated REE patterns ((La/Yb)_N = 21–179), and depleted in Nb, Ta, Ti and P. The biotite granitic gneisses have low Rb/Sr ratios (∼0.06) and weak positive Eu anomalies (δEu = 1.26–1.51), while the granites have low Th, U and REEs and strong positive Eu anomalies (δEu = 7.27–16.92). The zircons of these granitic rocks generally have core–rim structures based on cathodoluminescence images and show inherited ages of 2729 ± 10 Ma, crystallization ages of 2523 ± 11 Ma to 2526 ± 15 Ma, and crystallization/metamorphism ages of 2480 ± 15 Ma to 2485 ± 9 Ma. The zircon Hf isotope results of the medium-grained monzogranite show that the εHf(t2) values vary from –2.2 to +5.3, and the two-stage model ages (T_DM2) are 2.9–3.0 Ga. The magmatic zircons of the early Neoarchean (∼2.73 Ga) and the late Neoarchean (∼2.52 Ga) crystallized in high-temperature magmas (738–890 °C), whereas those of the early Paleoproterozoic (∼2.48 Ga) crystallized in relatively low-temperature (646–702 °C) magmas. These results indicate that the Jiapigou granitic rocks were products of intracrustal recycling during the late Neoarchean and the early Paleoproterozoic. The protoliths of the Jiapigou granitic gneisses were derived from the remelting of the early Neoarchean juvenile crustal rocks in the lower crust during the late Neoarchean. Subsequently, these granitic rocks underwent amphibolite-facies metamorphism and water-fluxed melting in the early Paleoproterozoic, resulting in the association of migmatic granitic gneisses and potassic granites at the shallow crust level. The cratonization in the Jiapigou terrane involved early Neoarchean (∼2.73 Ga) juvenile crust growth and late Neoarchean (∼2.53–2.52 Ga) to the early Paleoproterozoic (∼2.48 Ga) intracontinental reworking.

新太古代花岗岩是前寒武纪克拉通的重要组成部分，其岩石成因可为认识大陆地壳演化提供约束。新太古代钾质花岗岩广泛分布于吉林省南部，位于华北克拉通东北部。新获得的野外地质观测和岩石学、地球化学和地质年代学资料表明，夹皮沟钾质花岗岩杂岩主要由黑云花岗片麻岩和中粗粒花岗岩组成。所有的花岗质片麻岩和花岗石都是高钾钙-碱性至磷钾长石，金属铝质至过铝质（A/CNK = 0.95-1.13；摩尔 Al ₂ O ₃ /（CaO + Na ₂ O + K ₂O))，富含具有强烈分馏 REE 模式的 LILEs 和 LREEs （(La/Yb) _N = 21–179），并缺乏 Nb、Ta、Ti 和 P。 0.06）和弱正 Eu 异常（δEu = 1.26-1.51），而花岗岩具有低 Th、U 和 REE 和强正 Eu 异常（δEu = 7.27-16.92）。这些花岗岩的锆石一般具有基于阴极发光图像的核缘结构，遗传年龄为2729±10Ma，结晶年龄为2523±11Ma～2526±15Ma，结晶变质年龄为2480±15Ma～ 2485±9 毫安。中粒二长花岗岩的锆石 Hf 同位素结果表明，εHf(t2) 值在 –2.2 到 +5.3 之间变化，两阶段模型年龄 (T _DM2) 为 2.9-3.0 Ga。新太古代早期 (~2.73 Ga) 和新太古代晚期 (~2.52 Ga) 的岩浆锆石在高温岩浆 (738-890 °C) 中结晶，而古元古代早期 (~ 2.48 Ga）在相对低温（646-702°C）的岩浆中结晶。这些结果表明夹皮沟花岗岩是新太古代晚期和古元古代早期地壳内循环的产物。夹皮沟花岗片麻岩的原岩来源于新太古代晚期下地壳中新太古代早期幼年地壳岩石的重熔。随后，这些花岗岩在古元古代早期经历角闪岩相变质作用和水熔作用，导致浅地壳水平的混合花岗岩片麻岩和钾质花岗岩的结合。