Sulfur and oxygen isotope systematics in the Coates Lake stratiform copper deposit (Redstone), N. W. T. , Canada

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

OSTI ID:6318160

Lustwerk, R L; Rye, R O; Rose, A W

Sulfur and oxygen stable isotope studies of sulfates and sulfides in the Proterozoic Coates Lake stratiform copper deposit show complex patterns indicative of several different processes. Isotopic values of anhydrite and gypsum in ore, interlayered red and green horizons, and underlying red beds dominantly reflect the initial depositional environment: an alternation of continental and marginal marine facies during transgression. Subtle variations in the sulfate sulfur signatures are a result of the interaction between the end member continental and marine environments. The lack of an increase in delta/sup 34/S of the sulfate in the ore horizons with increasing amounts of sulfide supports the petrographic observation that copper and copper-iron sulfides replace pre-existing anhydrite and gypsum. Sulfate oxygen data commonly display high values which do not discriminate between environments effectively as the sulfur. Concomittantly depressed values of both sulfur and oxygen in some beds are thought to be the result of the oxidation of small amounts of sulfide with negative delta/sup 34/S. Although the deposit displays a wide range of sulfide delta/sup 34/S values, individual beds possess characteristic, and more restricted, signatures which become heavier stratigraphically higher. In addition, two populations of pyrite can be discerned--an early diagenetic population with negative delta/sup 34/S and an ore-stage pyrite with positive delta/sup 34/S. It is proposed that the transition to heavier delta/sup 34/S in the sulfides can be used to trace the path of the ore-forming solution and its interaction with sedimentary sulfate and organic matter.

• Research Organization: Pennsylvania State Univ., University Park (USA)
• OSTI ID: 6318160
• 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)
CANADA
CHEMICAL COMPOSITION
CHEMISTRY
COPPER ORES
DIAGENESIS
GEOCHEMISTRY
GEOLOGIC HISTORY
GEOLOGY
ISOTOPE RATIO
ISOTOPES
MINERALIZATION
MINERALOGY
MINERALS
NORTH AMERICA
NORTHWEST TERRITORIES
ORES
OXYGEN ISOTOPES
PETROGENESIS
PETROLOGY
SULFATE MINERALS
SULFIDE MINERALS
SULFUR ISOTOPES