Veins, Dikes, and Pods of the UAE Mantle Peridotites: Possible Industrial Raw Materials

The northern extension of the Semail ophiolite in the UAE is dominated by tectonic mantle peridotites and gabbros. The peridotites are mostly harzburgite with little lherzolites and contain various intermittent veins, dikes, and pods. These veins, dikes, and pods can be divided into three rock categories: the ultramafic group that includes dunites, chromitites, and pyroxenites; the granitic dikes; and carbonate veins. Occurrences of these bodies are explicit and ubiquitous, but their distribution is not consistent throughout the sequence. Pyroxenites, chromitites, and granites occur in the upper half of the sequence, but more pronouncedly and dominantly close to the transition zone. Dunites pods and carbonate veins can be found at different stratigraphic levels. Magmatic signatures and monomineralic forms of the three ultramafic varieties are observed. Where it occurs, chromite-rich variety is always enveloped in olivine-rich pods. Coarse-grained mica-rich granites and pegmatites are well developed below and within the transition zone. Carbonates, and occasionally serpentine materials, impregnate through fractures and structures.

These rocks and their host peridotites offer a range of probable industrial raw materials that can be exploited accordingly. Carbonates, e.g., magnesite and dolomite, are important in refractory protection and cupellation process. The resistant property of granites to mechanical and chemical weathering has made them favored from other alternative rocks in multiple uses such as landscaping, road base and concrete aggregates, wall and floor tiles, raw building stones, and so on. The ultramafic bodies and their host peridotites mainly occur at the eastern part of the country. In addition to their use as foundation materials and some like chromitites as metallic commodity, they have recently become efficiently and environmentally preferred in iron and steel industry and in probable CO₂ sequestration.