Calibrating heavy rare-earth elements (HREE) partitioning between monazite and garnet is a direct way to link datable accessory phases with major minerals, and is therefore vital for the interpretation of geochronological data and the establishment of P–T–t paths. However, HREE partitioning (D_HREE) data for monazite and garnet are lacking for high-temperature–ultrahigh-temperature (HT–UHT: 850–1000 °C) conditions and published data under sub-solidus conditions (600–750 °C) show large variations. We empirically determine D_HREE+Y between monazite and garnet that formed during near isobaric cooling along a P–T–t path from ~ 980 °C to 830 °C at ~ 9 kbar from 1.90 to 1.85 Ga from 6 UHT aluminous granulite samples in the Khondalite Belt of North China Craton. The calculated HREE + Y partitioning results overlap at the hand specimen to microdomain scale, implying bulk chemical equilibrium between monazite and garnet. The D_Y (20 ± 9) and D_Dy (50 ± 17) can be used to differentiate equilibrated and unequilibrated monazite–garnet pairs, while D_Gd is indistinguishable and D_Er has a large uncertainty. Our newly calibrated D_Y and D_Dy, in combination with a compilation of previously published results, indicate different monazite behaviour under sub-solidus and supra-solidus conditions, which might be related to the exhaustion of xenotime. The newly calculated HREE + Y partitioning under HT–UHT conditions can be used as an additional guide to decipher polymetamorphic evolution in high-grade terranes, and provides a basis for future experimental study.

校准独居石和石榴石之间的重稀土元素 (HREE) 分配是将可测副相与主要矿物联系起来的直接方式，因此对于解释地质年代学数据和建立P - T - t路径至关重要。然而，缺乏高温-超高温（HT-UHT：850-1000 °C）条件下独居石和石榴石的HREE 分配（D _HREE）数据和亚固相线条件（600-750 °C）下的公开数据表现出很大的变化。我们凭经验确定了在沿P-T-t 的近等压冷却过程中形成的独居石和石榴石之间的D _HREE+Y华北克拉通孔达岩带中 6 个 UHT 铝麻粒岩样品在约 9 kbar 压力下从 1.90 到 1.85 Ga 从 ~ 980 °C 到 830 °C 的路径。计算出的 HREE + Y 分配结果在手标本到微域尺度上重叠，这意味着独居石和石榴石之间的整体化学平衡。所述d _ÿ（20±9）和d_镝（50±17）可被用于区分平衡和非平衡独居石石榴石对，而d_的Gd是不可区分和d_尔具有大的不确定性。我们新校准的D _Y和D _Dy，结合先前发表的结果汇编，表明在亚固相线和超固相线条件下不同的独居石行为，这可能与磷钇矿的耗尽有关。HT-UHT条件下新计算的HREE+Y分区可作为破译高品位地体多变质演化的额外指南，并为未来的实验研究提供基础。