Igneous rocks related to abnormal high heat flow preserved in ancient convergent margins provide direct clues to identify fossil ridge-subduction. The Khanka Massif, as a witness of the final termination of the Paleo-Asian Ocean in Late Paleozoic, provides an ideal opportunity to trace the fossil ridge-subduction. Different types of Permian igneous rocks (282–255 Ma) were identified in composition from mafic to felsic. The mantle-derived mafic rocks are further subdivided into two groups. Group I are arc-featured rocks with normal mantle-like features in Mg isotopes. Permian subduction setting was therefore proposed within western margin of Khanka Massif, supported by the coeval arc-featured granitoids and the detrital zircon cumulative proportion curves. By contrast, Group II are tholeiitic and have more depleted Sr-Nd-Pb-Hf isotopic compositions similar to MORB of Paleo-Asian Ocean. In addition, the decoupling between Sr-Nd-Pb-Hf and Mg isotopes indicate isotope exchange between MORB and magnesite. High heat condition is therefore required because of the decomposition reactions of magnesite. The crust-derived felsic rocks exhibit the prominent difference in Sr-Nd-Pb-Hf-Mg isotopic compositions, implying synchronous melting of the continental and oceanic crusts, which are supported by the high zircon saturation temperatures (855–935 °C). Consequently, an ‘abnormal high-heat condition’ caused by ridge subduction and resultant slab window is the most likely model to reconcile the diversiform magmatism and tectonic evolution along the west margin of the Khanka Massif in the Permian. Sr-Nd-Pb-Hf-Mg isotopes are therefore verified as an integrated tracer to decipher the magmatic response to the ridge-subduction in ancient subduction zone.

与古代收敛的边缘中保存的异常高热流有关的火成岩提供了直接的线索来识别化石脊俯冲。汉卡地块是古生代晚期亚洲古海洋最终终结的见证，是追踪化石脊俯冲的理想机会。从镁铁质到长岩质，鉴定出不同类型的二叠纪火成岩（282-255 Ma）。来自地幔的镁铁质岩石又细分为两组。第一组是镁同位素中具有正常地幔状特征的弧状岩石。因此，在汉卡断层块的西边缘内提出了二叠纪俯冲的背景，并辅以同时代的弧特征花岗岩和碎屑锆石累积比例曲线。相比之下，第II组是高脂类的，且具有与古亚洲海洋MORB相似的更多的Sr-Nd-Pb-Hf同位素组成。此外，Sr-Nd-Pb-Hf与Mg同位素之间的解偶联表明MORB与菱镁矿之间存在同位素交换。因此，由于菱镁矿的分解反应，因此需要高温条件。源自地壳的长英质岩石在Sr-Nd-Pb-Hf-Mg同位素组成上表现出显着差异，这意味着大陆和海洋地壳的同步熔融，这受到高锆石饱和温度（855-935°C）的支持。因此，由脊俯冲和由此产生的板片窗口引起的“异常高温条件”是调和二叠纪汉卡地块西缘的多种岩浆作用和构造演化的最可能模型。