Reconnaissance geochemical exploration for gold in the Ad Darb area, Kingdom of Saudi Arabia

Open-File Report 90-285

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Geochemical data were analyzed for 244 wadi-sediment samples in an attempt to locate gold exploration targets in late Proterozoic metasedimentary and metavolcanic rocks in the Ad Darb area of the southern Arabian Shield. The target was gold mineralization in high-alumina alteration zones of the type that occurs in the Carolina Slate Belt, eastern United States. Such a target was sought in the Ad Darb area because of the known presence of kyanite in schist of the Sabya formation, which was interpreted to be a possible indicator of late Proterozoic high-alumina hydrothermal activity in the region.

Overall, metal values in the wadi-sediment samples are low. The known kyanite mineral occurrence is marked by anomalous gold and tin in three minus-80-mesh samples. The low values of the metals do not justify further exploration for the sought deposit type in the immediate vicinity, although the signature of anomalous elements in the wider region is comparable to the signature known in the Carolina Slate Belt, and is permissive of the interpretation that a diffuse hydrothermal system operated in the region during the late Proterozoic. A large concentration of polymetallic anomalies (gold, arsenic, copper, antimony, tin, tungsten, and lead) is outlined in the northeastern part of the survey area on the basis of panned-concentrate samples. The source of the concentration is unknown, and further investigations are recommended. Recommended low-priority investigation of the source of lead and zinc anomalies in the western part of the survey area would be justified as part of a larger program designed to evaluate the mineral potential of the entire belt of Sabya formation rock.

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USGS Numbered Series
Reconnaissance geochemical exploration for gold in the Ad Darb area, Kingdom of Saudi Arabia
Series title:
Open-File Report
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U.S. Geological Survey
Publisher location:
Reston, VA
Report: iii, 54 p., ill.
Saudi Arabia
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