A major lineament in the Arabian Shield and its relationship to mineralization

The Al Amar Fault lies in a belt of Proterozoic, metamorphosed volcanic and sedimentary rocks, bounded by granitic batholiths. A string of metalliferous and industrial mineral deposits form a “mineral belt” which coincides with the volcanosedimentary belt. Orebodies of basic and ultra-basic association are directly related to the fault through its influence on intrusive activity. Cu-Zn-Au bearing veins of meta-volcanic affiliation are spatially related to the fault. A group of Pb-Ag bearing veins is associated with the granitic batholith which forms the western boundary of the volcano-sedimentary belt. Associations between ore minerals and particular igneous rocks indicate that granitic, basic and metamorphosed volcanic rocks were sources of Pb-Ag-W-Mo, Fe-Cr-Cu-Ni and Fe-Cu-Zn-Au-Ba, respectively. Hydrothermal activity in the fault zone promoted ore formation, and faulting provided sites for deposition. Al Amar Fault is a “copper-lead line” dividing a Pb-Ag subprovince (of sialic derivation?) from a Cu-Zn-Au sub-province (of plate margin/island arc derivation?). The fault is a useful empirical guide in exploration for ores of basic or ultra-basic plutonic and meta-volcanic affiliation and can be identified and traced, as a lineament, using ERTS satellite images and aeromagnetic maps.