The Hamdah prospect is a 1.5-km 2 area that includes ancient mine workings 15 km southeast of Hamdah in the southern Arabian Shield. The workings cluster at a gently dipping thrust contact between serpentinite (above) and hornblende schist (below) exposed in a window within the serpentinite. Aplite sills intrude the contact, and gold concentrations occur just above or below it. It is recommended that the thickness of the dumps be more accurately determined, and that the gold leachability of bulk dump material be tested. Shallow reverse-circulation drilling is recommended on 25-m centers in the northeast quadrant, and diamond drilling is recommended elsewhere at the prospect. Geophysical surveys are required to help establish depths to the serpentinite/schist contact on the northeastern, southern, and western margins of the prospect. Detailed mapping should be undertaken at the prospect, and a mineral-belt type of mapping program should be completed over the larger Hamdah region. Figure 1.-Index map of the Arabian Shield showing the location of the Hamdah region.

A follow-up exploration program was conducted in fifteen areas anomalous in precious and base metals within the Farah Garan-Kutam mineral belt, which forms part of a strongly deformed greenstone terrane in the southern part of the Proterozoic Arabian Shield. Using detailed chip-sample traverses, the program also evaluated four mineralized prospects, two of which (Raiah and Al Misadij prospects) had been recognized before the exploration program began; the additional two prospects (Kuhaym and Khathl prospects) were discovered during the course of the exploration program. Mineralized rock discovered during the exploration program consists of three types: (1) precious-and base-metal occurrences associated with large, lenticular, quartz-veined dolomitic bodies interpreted to be submarine exhalative deposits; the highest metal-concentration values are associated with silicified shear zones within the dolomite, which commonly were the sites of ancient mines; (2) precious-and base-metal mineralization associated with several small, isolated quartz veins scattered throughout the mineral belt; and (3) zones (several kilometers long and several hundred meters wide, with long axes oriented parallel to foliation) of variably silicified and pyritized greenstone and quartz-sericite phyllite; extensively dolomitized rock generally occurs in a zone surrounding the silicified and pyritized rock. Grades and (or) tonnages of all occurrences discovered during the exploration program are low the silicified and pyritized zones are entirely barren of base or precious metals-and no further work on them is recommended. The only significant mineralization discovered within the study area is located at the Raiah prospect, where a silicified shear zone (about 1 m wide) in lenticular exhalative dolomite body, contains as much as 5 ppm Au, 85 ppm Ag, 1.1 percent Cu, 2.6 percent Pb, and 10.7 percent Zn. Concentrations of the same elements within the surrounding dolomite are anomalously high, although they are significantly lower than values obtained in the shear zone. The inferred small tonnage of the deposit does not warrant further study.