A reconnaissance wadi-sediment geochemical survey for gold was conducted in the Bi'r Jarbuah Area (lat 20° 45' 00"-21 ° 00' 00" N., long 43° 30' 00"- 43° 41' 00" K). The area is located in the northern part of a regional concentration of gold occurrences, the Jabal Ishmas-Wadi Tathlith gold belt. Panned concentrates and minus-80-mesh fractions were obtained from 300 samples collected from a 320 km2 area and analysed by atomic-absorption spectroscopy. Analyses of the pannedconcentrate samples proved to be more definitive than sieved samples in delineating areas of mineralization. Most of the anomalous gold-and arsenic-bearing wadi-sediment samples are located along an irregular contact between gneissic and dioritic rocks in the center of an area characterized by the presence of subparallel dacitic dike swarms.
Most of the ancient gold mines are also located along this contact. Gold is associated with arsenic but not with silver. Five areas containing gold-anomalies areas and 6 areas containing tellurium anomalies and the contact zone between the diorite and the paragneiss are recommended for further investigation of precious-metals resources.
|Title||Reconnaissance wadi-sediment geochemical survey of the Bi'r Jarbuah area, Kingdom of Saudi Arabia|
|Authors||Rashid M. Samater, Ralph P. Christian, Bruce M. Walker|
|Publication Subtype||USGS Numbered Series|
|Series Title||Open-File Report|
|Record Source||USGS Publications Warehouse|