Fluid inclusion and stable isotope study of telluride mineralization at Mahd Adh Dhahab, Saudi Arabia

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6675818

Afifi, A M; Kelly, W C

Mahd Adh Dhahab is unique among Precambrian gold deposits in that it displays many characteristics of epithermal precious metal districts. Au-Ag-Cu-Zn-Pb mineralization occurs principally in the third of five generations of quartz veins. Sulfur isotopic equilibrium was generally maintained among sulfides which range in delta/sup 34/S from -1.8 (galena) to 6.4 (pyrite). The narrow range in delta/sup 34/S of sulfides is inconsistent with large variations in f02 calculated from chlorite +/- pyrite +/- hematite assemblages. Galena-sphalerite pairs yield temperatures in the range 160-270/sup 0/C for stage 3 veins, which fall within the 120-300/sup 0/C range defined by fluid inclusion thermometry. Fluid salinities are in the range 0.5 wt.% NaCl equivalent. The trends indicate mixing of delta/sup 18/O approx. = 0 waters with heavier more oxidized waters during stage 4 deposition which led to non-equilibrium oxidation of H/sub 2/S. deltaD values of vein chlorites fall within a narrow range of -65 to -75, while deltaD measurements of inclusion fluids in quartz display a wider spread from -13 to -43; the lighter values may reflect contamination by secondary inclusions. The stable isotope data indicate probable derivation of both sulfur and carbon from igneous sources. District-wide variation in sulfur and oxygen isotopes indicate the presence of several hydrothermal centers, which has possible significance to exploration.

• Research Organization: Univ. of Michigan, Ann Arbor (USA)
• OSTI ID: 6675818
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
ASIA
CHALCOGENIDES
CHLORITE MINERALS
COPPER
ELEMENTS
GALENA
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GOLD
GOLD ORES
HEMATITE
HYDROTHERMAL ALTERATION
HYDROTHERMAL STAGE
INCLUSIONS
IRON COMPOUNDS
IRON ORES
IRON OXIDES
IRON SULFIDES
ISOTOPE RATIO
ISOTOPES
LEAD
LEAD COMPOUNDS
LEAD SULFIDES
METALS
MINERALIZATION
MINERALOGY
MINERALS
ORES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PRECAMBRIAN ERA
PYRITE
QUARTZ
SAUDI ARABIA
SILICATE MINERALS
SILICON COMPOUNDS
SILICON OXIDES
SILVER
SPHALERITE
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
SULFUR ISOTOPES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
ZINC