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The mantle section of the Late Neoproterozoic Tays ophiolite in the Arabian Shield consists principally of thoroughly serpentinized peridotite with characteristics typical of depleted mantle protoliths from a fore-arc environment. The serpentinite is altered along shear zones and thrust planes to gold-bearing listvenite bodies of various sizes. These bodies are divided into carbonate listvenite and silica‐carbonate listvenite; they may be dyke-like or lenticular in form, and are yellowish-brown, reddish-brown, or greyish in outcrop. Carbonate list- venite expresses schistose deformation fabrics concordant to fabric in the host serpentinite, whereas silica‐car- bonate listvenite is undeformed at field scale and contains a generation of undeformed minerals at thin-section scale. Silica‐carbonate listvenite contains Cr-rich muscovite (fuchsite) and base-metal sulfides and is enriched in Zn, Pb, Cu, Ag, and Au along with SiO2. The transformation of serpentinite along shear zones to different types of listvenite reflects successive episodes of fluid-mediated metasomatism. Carbonate listvenite develops first, driven by infiltration of CO2–bearing fluids during serpentinization of the original fore-arc peridotite. Silica‐carbonate listvenite marks a later episode associated with infiltration of K-bearing, SiO2-saturated fluids released during emplacement of the ophiolite. Listvenitization in the Tays serpentinite concentrated gold in sub-economic to economic extents, with concentrations increasing from host serpentinite (2–4 ng/g) to carbonate listvenite (267–937 ng/g) to silica‐carbonate listvenite (1717–3324 ng/g). 

Loveringite, a rare member of the crichtonite group with nominal formula (Ca,Ce)(Ti,Fe,Cr,Mg)21O38, was found in the Khamal layered mafic intrusion, the first known locality for this mineral in the Arabian Shield. The Khamal intrusion, a large post-collisional mafic complex, is lithologically zoned, bottom to top, from olivine gabbro through gabbronorite, hornblende gabbro, anorthosite, and diorite to quartz diorite. Loveringite is found near the base of the complex, as an intercumulus phase in olivine gabbro. Most loveringite grains are homogeneous, although a few grains are zoned from cores rich in TiO2, Al2O3, Cr2O3, and CaO towards rims rich in FeO*, ZrO2, V2O3, Y2O3, and rare earth elements (REE). Petrographic relations indicate that loveringite formed after crystallization of cumulus olivine, pyroxenes, and plagioclase. Anhedral and corroded crystals of loveringite are surrounded by reaction rims of Mn-bearing ilmenite and baddeleyite, suggesting that the residual liquid evolved into and subsequently out of the stability field of loveringite. The budget of incompatible elements (Zr, Hf, REE, U, and Th) hosted in loveringite is anomalous for a primitive mafic liquid. Saturation in loveringite is likely the result of early contamination of the primary melt by anatexis of country rock, followed by isolation of evolving liquid in intercumulus space that restricted communication with the overlying magma chamber. The zoned crystals likely reflect diffusive equilibration between residual loveringite grains and their reaction rims of ilmenite.