Genesis of the Spar Lake strata-bound copper-silver deposit, Montana; Part I, Controls inherited from sedimentation and preore diagenesis

Rhenium

“…As for acid-generating sulfides, the ore for all three subtypes contain low pyrite contents. The pyrite content of the host rock for all types of sediment-hosted copper deposits is less than 1 volume percent (Hayes and Einaudi, 1986).…”

Platinum-group elements in sedimentary environments in the conterminous United States

“…Metamorphism: Regional greenschist-facies metamorphism is characteristic of several of the basins (for example, metasedimentary rocks of the Belt Supergroup (Hayes and Einaudi, 1986)), whereas rocks in other basins (midcontinental U.S.) are not metamorphosed. The metamorphism, although post mineralization, may have, in some cases, remobilized and concentrated metals into deposits that may not otherwise have been economic (J.M.…”

“…However, a large proportion of the rocks within the basins formed from shallow-water deposits derived from deltaic and other near-shore sediments (Hayes and Einaudi, 1986;LaPoint, 1979;Johnson, 1976) that were shed into a subsiding basin. The basin is typically filled with a sequence of bimodal (Gregor Borg, unpub.…”

“…In some deposits they replace organic matter or pyrite (Gustafson and Williams, 1981), whereas in other deposits, like Spar Lake (Hayes and Einaudi, 1986), the ore minerals occupy former pore spaces between detrital grains. Locally, small veinlets are present, and, in the case of deposits in the Lisbon Valley area, Utah, redbed-derived fluids deposited vein material along faults when reduced aquifers higher in the stratigraphic section were encountered (Morrison and Parry, 1986).…”

Mineral resources of the Quigg West Wilderness Study Area, Granite County, Montana

“…In the sandstone-hosted strata-bound copper-silver sulfide deposits, ore minerals occur in fine-to mediumgrained beds of quartzite, which commonly are crossbedded (Clark, 1971;Harrison, 1974;Hayes and Einaudi, 1987). Deposits of this type are known in prospects about 20-25 mi southeast of the study area (J.E.…”