Vincent J. Flanigan Habib M. Merghelani Ronald G. Worl 1976 <p>The Umm Al Khabath copper prospect (lat 20°10'N.; long 41°23'E.) was tested by 815 m of diamond drilling in three holes. Meager metallization of copper, zinc, gold, and silver is related to a distinct phase of quartz-pyrite veinlet stockworks and associated silicification, sericitization, and pyritization. Alteration and metallization are within a major north-trending shear zone, 10-50 m wide. Lithologies cut by the shear zone are pyroclastic agglomerate and tuff with intercalated ferruginous chert, wacke, and basalt flows, all belonging to the Precambrian Baish Group. The outcrop of the shear zone for a length of 1400 m contains scattered gossan, local zones of abundant malachite and chrysocolla veinlets, patches of malachite-rich calcrete cap, and several shallow ancient workings. Composite chip samples taken from the surface across the sheared and altered zone contain anomalous concentrations of copper and zinc in amounts greater than can be expected from the weathering of the slightly metallized rock of the sheared and altered zone.</p> application/pdf 10.3133/ofr78521 en U.S. Geological Survey Evaluation of the Umm Al Khabath copper prospect, Jabal Ibrahim quadrangle, sheet 20/41C, Kingdom of Saudi Arabia reports