Like the Moldanubian parts of the Bohemian Massif and the French Massif Central, the Vosges Mts (NE France) comprise an uppermost tectonic unit that consists of retrograded (U)HP/UHT granulites, eclogites and garnet peridotites, originally metamorphosed at pressures of ≥ 4 GPa and temperatures of ≥ 950 °C. Two amphibole–garnet–spinel-bearing peridotite bodies located near to Col des Bagenelles (CB) and Crébimont (CR) show a pronounced retrograde evolution. Primary garnet was completely transformed to a symplectite of orthopyroxene + clinopyroxene + Cr-poor spinel ± amphibole, partially surrounded by a discontinuous outer zone of coarser grains of pyroxenes ± amphibole. Such symplectites are typical for the sliding reaction garnet + olivine ± Na₂O ± K₂O ± H₂O = orthopyroxene + clinopyroxene + spinel ± amphibole. Both peridotites contain ‘primary’ Cr–Al–spinel. In the sample from CB, such grains occur only within the symplectites after garnet, but never in the matrix, while in the sample from CR, Cr–Al–spinel is present as inclusions within the symplectites and as isolated grains within the surrounding matrix. In the peridotite from CR, that is more depleted than that from CB, these Cr–Al–spinel grains show intense chemical zoning with Cr and Fe²⁺ decreasing, but Al and Mg increasing from core to rim. This pattern is interpreted as retrograde zoning during decompression. Primary P–T conditions deduced from compositions of matrix pyroxenes under the assumption of equilibration with earlier garnet are ≥ 1.6–1.7 GPa/ ≥ 900 °C for sample CB, but ≥ 2.3 GPa/ ≥ 860 °C for sample CR. Temperature conditions during the breakdown of garnet are indicated by pyroxenes from the symplectites and are 833 ± 18 (CB) and 812 ± 11 °C (CR) using the Ca-in-Opx thermometer at a chosen pressure of 1.3 GPa.

与波西米亚地块的摩尔达努比亚部分和法国地块中部一样，孚日山脉（法国东北部）包括一个最上层的构造单元，由回生 (U)H P /UH T麻粒岩、榴辉岩和石榴石橄榄岩组成，最初在≥ 4 GPa 和温度≥ 950 °C。位于 Col des Bagenelles (CB) 和 Crébimont (CR) 附近的两个含闪石-石榴石-尖晶石的橄榄岩体显示出明显的逆行演化。原生石榴石完全转变为斜辉石 + 单斜辉石 + 贫铬尖晶石 ± 角闪石的辛辉石，部分被较粗的辉石 ± 角闪石的不连续外部区域包围。这种辛晶石是典型的滑动反应石榴石 + 橄榄石 ± Na ₂ O ± K₂ O ± H ₂ O = 斜辉石 + 斜辉石 + 尖晶石 ± 闪石。两种橄榄岩都含有“原生”Cr-Al-尖晶石。在来自 CB 的样品中，此类晶粒仅出现在石榴石之后的辛晶中，而从未出现在基体中，而在来自 CR 的样品中，Cr-Al-尖晶石作为夹杂物存在于辛晶中，并作为周围基体中的孤立晶粒存在。在 CR 橄榄岩中，比 CB 更贫化，这些 Cr-Al-尖晶石晶粒显示出强烈的化学分带，Cr 和 Fe ²⁺减少，但 Al 和 Mg 从核心到边缘增加。这种模式被解释为减压期间的逆行分区。初级P-T在假设与早期石榴石平衡的情况下，从基质辉石的组成推导出的条件对于样品 CB ≥ 1.6–1.7 GPa/≥ 900 °C，但对于样品 CR ≥ 2.3 GPa/ ≥ 860 °C。石榴石分解过程中的温度条件由辛辉石的辉石指示，使用 Ca-in-Opx 温度计在 1.3 GPa 的选定压力下为 833 ± 18 (CB) 和 812 ± 11 °C (CR)。