الملخص

ABSTRACTSporadic copper – iron opaque minerals are found associated with metabasalts of the Mawat ophiolite complex, NE Iraq. These minerals are found as disseminations and in veins cross – cutting the host rocks. The essential opaque minerals are chalcopyrite and pyrite with minor iron oxide minerals namely magnetite and hematite. Fe – hydroxides and copper chloride minerals represent the secondary products of chalcopyrite oxidation. The presence of these opaque assemblages is related to the tectonic evolution of the Mawat ophiolite complex originated at fore – arc suprasubduction zone ( SSZ ) and is explained by deposition from hydrothermal solutions during basalt – seawater interaction that causes also the metamorphism and alteration of the studied metabasalts.A particular finding of interest was the efficiency of nitric acid to extract measurable amounts of copper. A high copper extraction recovery ( 95% ) was obtained applying ion – exchange method on Dowex 50 resin after dissolving rocks in 4M nitric acid.