The peak temperature and timescale of ultrahigh-temperature (UHT) metamorphism are significant for understanding its thermal budget and geodynamic evolution. The spinel-bearing (sapphirine-absent) UHT granulite at the Xuwujia area in the Jining complex, North China Craton was revealed to have undergone a metamorphic evolution that involves the pre-T_max (maximum temperature) heating decompression to the T_max stage with an extreme temperature of ~1125 °C, the post-T_max cooling to the fluid-absent solidus (~860 °C) at 0.8–0.9 GPa, and sub-solidus decompression. The T_max condition was recorded by the inferred feldspar-absent peak assemblage of spinel ± garnet. The post-T_max cooling evolution was indicated by the sequential appearances of plagioclase, K-feldspar, sillimanite and biotite, as well as the core-to-rim ascending grossular component in garnet. Moreover, some texturally zoned spinel has exsolved lamellae of magnetite in the core and shows rim-ward increase of Mg and Al, which suggests a temperature decrease from >1100 °C in local domains isolated from quartz. Spinel with exsolved magnetite lamellae or low Al/(Al + Fe³⁺) is therefore proposed as an indicator for UHT conditions in metapelites. Probability simulation on the collected zircon ages yields a timescale of ~40 Myr (95% confidence; during 1.90–1.94 Ga) for the supra-solidus cooling stage of the UHT metamorphism in the Jining complex. This extreme UHT metamorphism has reached the rock’s dry solidus (~1125 °C) and undergone slow cooling, which is interpreted to result from a post-orogenic plume activity with sufficient advective heating from hyperthermal mafic intrusions.

超高温（UHT）变质的峰值温度和时间尺度对于了解其热收支和地球动力学演化具有重要意义。揭示了华北克拉通济宁地区徐五家地区含尖晶石（不含蓝宝石）的UHT麻粒岩经历了变质演化，涉及到前T _max（最高温度）加热减压至T _max阶段，最高温度为〜1125°C，T _max冷却至0.8-0.9 GPa时无流体的固相线（〜860°C），然后进行亚固相线减压。所述Ť_最大条件由尖晶石±石榴石的推断长石不存在峰组合记录。后T斜长石，钾长石，硅线石和黑云母的相继出现，以及石榴石中核心至边缘的上升粒状成分，表明了_最大的冷却演化。此外，一些具有纹理区域的尖晶石已经溶解了铁心中的磁铁矿薄片，并且显示出Mg和Al的边缘向内增加，这表明从石英中分离出的局部区域的温度从1100°C开始下降。尖晶石具有溶解的磁铁矿薄片或低Al /（Al + Fe ³⁺因此建议使用）作为变质岩中超高温条件的指标。在济宁复杂的UHT变质的超固相冷却阶段，对收集的锆石年龄进行概率模拟得出的时间尺度约为40 Myr（置信度为95％；在1.90-1.94 Ga范围内）。这种极端的UHT变质作用已经达到了岩石的干燥固相线（〜1125°C），并经历了缓慢的冷却，这被解释为是由于造山后的羽状活动和高温镁铁质岩浆侵入对流加热的结果。