Granulite-facies marbles are part of the Archaean crust of the In Ouzzal terrane (Western Hoggar). Besides calcite and dolomite, these marbles are characterized by forsterite, spinel, phlogopite, diopside, amphibole, and magnetite. High-Mn ilmenite (MnO: 19.43 wt%), pyrophanite (MnO: 25.83 wt%), dissakisite-(Ce) (containing 12.2–14.38 Ce₂O₃ wt% and 8.3–12.3 wt% La₂O₃), F-rich clinohumite and Ba-rich-phlogopite occur locally. Ilmenite-pyrophanite and Ba-rich phlogopite (BaO: 11.68 wt%) are interpreted to be resulted of the hydrothermal processes during carbonate deposition; whereas, dissakisite-(Ce) is inferred to have resulted from light rare earth element (LREE) enrichment of these marbles by fluids released from the syenite intrusions. Clinohumite with X_Mg [= Mg/(Mg + Fe)] of 0.89–0.91, generated by hydration of forsterite-bearing dolomitic marbles, has the highest fluorine contents ever reported in the literature (3.25–4.62 wt%), resulting in a F/(F + OH) ratio as high as 0.8. Clinohumite is the only phase incorporating F where phlogopite, amphibole and apatite are absent. Thus, all the F present in the rock would be concentrated in clinohumite, resulting in extreme fluorine enrichment in some grains.

麻粒岩相大理石是 In Ouzzal 地体（Western Hoggar）太古代地壳的一部分。除了方解石和白云石，这些大理石的特征还包括镁橄榄石、尖晶石、金云母、透辉石、角闪石和磁铁矿。高锰钛铁矿 (MnO: 19.43 wt%), pyrophanite (MnO: 25.83 wt%), dissakisite-(Ce) (含有 12.2–14.38 Ce 2 _O 3 _wt % 和 8.3–12.3 wt% La ₂ O ₃), 局部产富 F 斜辉石和富 Ba 金云母。钛铁矿-黄铜矿和富钡金云母（BaO：11.68 wt%）被解释为碳酸盐沉积过程中热液过程的结果；而据推测，铁镁石-(Ce) 是由正长岩侵入体释放的流体对这些大理岩的轻稀土元素 (LREE) 富集造成的。含 X_{镁的斜辉石}[= Mg/(Mg + Fe)] 为 0.89–0.91，由含镁橄榄石的白云质大理岩水化生成，具有文献中报道的最高氟含量 (3.25–4.62 wt%)，导致 F/(F + OH) 比率高达 0.8。斜褐石是唯一包含 F 的相，其中不存在金云母、角闪石和磷灰石。因此，岩石中存在的所有 F 都将集中在斜辉石中，导致某些颗粒中的氟极度富集。