Hughes Creek Placer, Gibbonsville District, Lemhi Co., Idaho, USA
REF:Deposit:: LORAIN, S. H., AND METZGER, O. H., 1939, RECONNAISSANCE OF PLACER MINING DISTRICTS IN LEMHI COUNTY, IDAHO: USBM INF. CIRC. 7082, P. 31 - 32 Deposit:: 1939 RECON USBM INF. CIRC. 708 Production:: LORAIN, S. H., AND METZGER, O. H., 1939, USBM INDeposit:: USBM INC CIRC 7082 Deposit:: IDA BUR MNS PAMP 130 Commodities (Major) - Gold Deposit Type: Placer Development Status: Past Producer Host Rock Unit: Idaho Batholith Host Rock: Alluvium
Granitic rocks of Tertiary age in the Idaho Batholith and their relation to mineralization
E. H. Bennett
Idaho Bur. Mines and Geol., Dep. Lands, Moscow, Idaho, United States
Broad areas within and adjacent to the Idaho batholith of Cretaceous age are characterized by radiometric dates of Tertiary age, distinctive oxygen-hydrogen isotope values, and high background radioactivity. Reconnaissance mapping in the Atlanta lobe of the batholith has defined several plutons of Tertiary age that are exposed because of large-scale block faulting. Similar rocks occur extensively in the Bitterroot lobe and along the eastern edge of the batholith where they have been exposed mainly by erosion.These plutons are remarkably similar. Common characteristics include quartz monzonitic to granitic compositions, pink color, the presence of miarolitic cavities containing smoky quartz crystals, and a well-defined vertical joint system that results in the development of a rugged terrain. Smoky quartz crystals are useful for identifying and delineating these plutons. The Tertiary granitic intrusions contain twice the background radiation of the Cretaceous batholith units, as measured with a gamma ray spectrometer.Many of these plutons contain disseminated molybdenum, tungsten and tin mineralization and are spatially related to blacksand placer deposits that contain radioactive minerals. These intrusive rocks may be an important guide in exploring for deposits of sedimentary uranium and epigenetic sulfides of Tertiary age.
This record provided courtesy of AGI/GeoRef.
POTASSIC-CARPHOLITE AND THE MYTH OF CENTERVILLE, IDAHO
W. Chris Van Laer
2214 Aberdeen Street, Butte, Montana 59701, U.S.A.
E-mail address: asterism2000@cs.com
The type locality of the recently described mineral species potassic-carpholite was reported to be near Centerville, Idaho. This note sets the record straight; the correct type-locality, deliberately kept secret for 22 years, is here divulged; it is in the Fall Creek drainage, in the vicinity of Glens Peak, Boise County, Idaho.
Keywords: potassic-carpholite, type-locality information, Sawtooth batholith, Idaho.