Preliminary geologic map of the Butte 1 degree by 2 degrees quadrangle, western Montana

Origin of placer gold nuggets and history of formation of glacial gold placers, Gold Creek, Granite County, Montana

“…Cretaceous plutonic rocks (Wallace et al, 1986). Bedrock units are discontinuously covered by Pleistocene glacial till, outwash, lacustrine deposits, and Holocene alluvium.…”

“…2; Wallace et al, 1986). Sedimentary rocks are intruded by the Royal stock (granodiorite with a zircon fission track age of about 66 Ma; Baty, 1976) and dikes and sills of Cretaceous diorite porphyry (Wallace et al, 1986).…”

“…2; Wallace et al, 1986). Sedimentary rocks are intruded by the Royal stock (granodiorite with a zircon fission track age of about 66 Ma; Baty, 1976) and dikes and sills of Cretaceous diorite porphyry (Wallace et al, 1986). Narrow, fissure-filling quartz veins containing gold, silver, copper, and lead have been explored in several mines and prospects in the headwaters of Gold Creek, in and near the borders of the Royal stock ( Fig.…”

“…, Pardee suggests that the stream gravel represents multicyclic deposits. A simpler interpretation can be deduced from recent work, which has correlated Pardee's terrace gravels with Pliocene pediment gravels that have been mapped in the Gold Creek and Deer Lodge basins (Fields et al, 1985;Wallace et al, 1986). Loen (1986) determined that these Pliocene gravels were mined for gold in the Pioneer district, and on these grounds, the stream gravel at the Pineau mine is correlated with Pliocene pediment deposits in the basin rather than with P]eistocene terraces as suggested by Pardee (1951).…”