Geology and hydrothermal alteration at the Madh adh Dhahab epithermal precious-metal deposit, Kingdom of Saudi Arabia

Doebrich, Jeff L.; LeAnderson, Jim

doi:10.3133/ofr84640

Cited by 5 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The overall composition of the rhyolite clearly indicates that it is altered. The high A12O3, Fe2O3, and K^O contents of these samples, as compared to most rhyolites, correlate with the evidence suggesting these rocks underwent an iritense episode of quartz-sericite-pyrite alteration (Doebrich and LeAnderson, 1984).…”

Section: Dec Lau Las Lts Uas and Rhy Sample Setssupporting

confidence: 55%

“…The objective of this particular study was to determine the trace-and major-element compositions and distribution patterns throughout the district, both on the surface and underground. Companion studies included studies of ore mineralogy, fluid inclusions, stable and lead isotopes (Rye and others, 1982), alteration assemblages and patterns (Doebrich and LeAnderson, 1984), and biogeochemical exploration techniques (Ebens and others, 1983).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Rock geochemistry in the Mahd adh Dhahab district, Kingdom of Saudi Arabia

Worl¹,

Doebrich²,

Allen³

et al. 1987

Open-File Report

Self Cite

View full text Add to dashboard Cite

Section: Dec Lau Las Lts Uas and Rhy Sample Setssupporting

confidence: 55%

mentioning

confidence: 99%

Rock geochemistry in the Mahd adh Dhahab district, Kingdom of Saudi Arabia

Worl¹,

Doebrich²,

Allen³

et al. 1987

Open-File Report

Self Cite

View full text Add to dashboard Cite

“…The area in the immediate vicinity of the mine, known as Jabal Mahd Adh Dhahab, was mapped in detail by Luce and others (1975), Worl (1978a), Huckerby and others (1983), and Doebrich and LeAnderson (1984). The underground workings were mapped by Dirom (in Hilpert and others, 1984), and by Gold Fields Mahd Adh Dhahab Ltd. (unpublished maps).…”

Section: Unconformitymentioning

confidence: 99%

“…HeTMIne HiHTlhyoliie^oinô f attention because of the apparent spatial association of ore with the rhyolite, which has led most previous workers (for example, Luce and others, 1979;Huckerby and others, 1983;Hilpert and others, 1984;Doebrich, 1984) to infer that mineralization was caused by intrusion of the rhyolite. This intrusion was mapped as feldspar porphyry (pi.…”

Section: Subvolcanic Rocks Of the Tuwal Formationmentioning

confidence: 99%

See 1 more Smart Citation

Geology of the Mahd Adh Dhahab District, Kingdom of Saudi Arabia

Afifi¹

1990

Open-File Report

View full text Add to dashboard Cite

Approximately 200 km2 around the Mahd adh Dhahab mine were mapped at 1:18,000 scale, with emphasis on establishing the volcanic stratigraphy. The Mahd Group, which rests over a basement of metamorphosed tonalite, is divided into the Lahuf formation and Tuwal formation, which are separated by an unconformity. The Lahuf is divided into a lower felsic pyroclastic member, a middle felsic tuff member, and an upper mafic member. The overlying Tuwal formation is divided into the Mine member, which consists predominantly of subaqueous felsic pyroclastic rocks with minor dolostone and chert, and the Ghuwayshat member, which consists predominantly of subaerial ignimbrites. The Mahd Group also contains numerous basaltic and rhyolitic subvolcanic intrusions, some of which were extruded as lava flows. The Mahd Group was folded, intruded by rocks of the Ramram cauldron, and eroded prior to deposition of the overlying Ghamr group. Remnants of the latter consist of fanglomerate, volcaniclastic sediments, and dacitic lava flows. Burial of the region under rocks of the Ghamr group probably accounts for prehnite-pumpelleyite facies metamorphism. Vein mineralization at Mahd adh Dhahab and other occurrences is probably unrelated to the magmatism that produced the Mahd and Ghamr groups. The Wadi Sayilah-Wadi Ghadayrah fault system was active during deposition of the Mahd and Ghamr groups and accounts for about 2.6 km of cumulate uplift of the basement block relative to the Mahd basin. Major-element data show that the Mahd Group was produced from separate basaltic and dacitic-rhyolitic magmas that overlapped without mixing. The alkalis and alkaline-earth elements were particularly mobile during metamorphism (which caused widespread albitization of feldspars) and also during hydrothermal alteration (which added secondary microcline). This mobility adversely affected rubidium-strontium whole-rock systematics, which makes whole-rock isochron dates obtained from these rocks questionable. The new geological data presented here are combined with the geochronologic data of Calvez and Kemp (1982) to re-interpret the geologic history of this area.

show abstract

Magmatic—Hydrothermal Deposits (Intrusion-Related Deposits)

Ahmed

2022

Mineral Deposits and Occurrences in the Arabian–Nubian Shield

View full text Add to dashboard Cite

Geology and hydrothermal alteration at the Madh adh Dhahab epithermal precious-metal deposit, Kingdom of Saudi Arabia

Cited by 5 publications

References 4 publications

Rock geochemistry in the Mahd adh Dhahab district, Kingdom of Saudi Arabia

Rock geochemistry in the Mahd adh Dhahab district, Kingdom of Saudi Arabia

Geology of the Mahd Adh Dhahab District, Kingdom of Saudi Arabia

Magmatic—Hydrothermal Deposits (Intrusion-Related Deposits)

Contact Info

Product

Resources

About