A PRELIMINARY ASSESSMENT OF THE PLATINUM GROUP MINERALS AND ASSOCIATED SULFIDES IN THE CHROMITES OF THE UAE SEMAIL OPHIOLITE

Ophiolites are characterized by a unique succession of rocks that are very attractive for geologists everywhere in the world. An excellent example of these is well exposed at the north eastern continental margin of the Arabian Peninsula, forming what is known as the Semail ophiolite. This ophiolite forms the largest part of the 700 km arcuate Oman Mountains with an integral part in the UAE.

The Semail ophiolite is one of the best examples of ophiolite assemblages, with definite crustal and mantle sequences. The mantle sequence represents the upper oceanic mantle, and is predominantly tectonic peridotites of mainly harzburgites with little lherzolites and dunites. In addition, different dikes and lenses of various types and thicknesses have been found within the mantle tectonic peridotites. Though, these dike and lenses have shown a wide range of diversity, varying from ultramafic, mafic, to felsic compositions, and extends from few millimeters to several meters thick, A large group of them are chromite ores commonly mantled within dunite envelopes.

The platinum group elements (PGE) and minerals (PGM) as well as many sulfides are one of the most important economic and industrial minerals. Recent studies on chromitite ores and associated rocks of some ophiolites such as in China, Greece, Italy and Cuba have shown an existence of PGM inclusions and other sulfides in chromite minerals and related rocks of ophiolites. In the UAE ophiolite, many chromite localities had been mined in the period between 1990 to 2000. However, assessment of the PGE minerals and other sulfides of these chromite ores and related rocks have never been done before. This study has investigated these important minerals in chromites or chromitites and some associated rocks in the UAE part of the Semail ophiolite. Preliminary results have shown similarities with those found in the other harzburgitic type ophiolites. However, the continual work is expected to find some significances.