USGS - science for a changing world

Mineral Resources On-Line Spatial Data

Argillite, siltite, and quartzite; Middle Proterozoic Ravalli Group; northern Belt Province

Intermediate Precambrian sediments, multicolored siltite and argillite overlying quartzite and siltite of northern Idaho.
StateIdaho
NameArgillite, siltite, and quartzite; Middle Proterozoic Ravalli Group; northern Belt Province
Geologic ageMiddle Proterozoic
Original map labelY2n; Y?n
CommentsSiltstone and shale generally are metamorphosed to siltite and argillite. Quartzite is vitreous and feldspathic to sericitic. Burke is gray, with sand-clay couplets and flat-laminated sands. Revett quartzite is pale gray and flat laminated to cross-bedded. Revett argillite-siltite has ripple marks and mudcracks, and commonly is lavender or green. St. Regis commonly is maroon to purple and has mudcracked sand-to-clay couplets, sandy beds and interclasts.
Primary rock typemeta-argillite
Secondary rock typesiltstone
Other rock typesquartzite
Lithologic constituents
Major
Metamorphic > Quartzite (Bed)quartzite, some vitreous, some sericitic
Sedimentary > Clastic > Siltstone (Bed)siltite in beds, and in graded couplets
Metamorphic > Argillite (Bed)argillite in graded siltite-argillite couplets, beds, partings
Map references
Bond, J.G., Kauffman, J.D., Miller, D.A., and Venkatakrishnan, Ramesh, 1978, Geologic map of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, with contributions from U.S. Geological Survey, scale 1:500,000.
Unit references
Bond, J.G., Kauffman, J.D., Miller, D.A., and Venkatakrishnan, Ramesh, 1978, Geologic map of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, with contributions from U.S. Geological Survey, scale 1:500,000.
Anderson, H.E. and Parrish, R.R., 2000, U-Pb geochronological evidence for the geological history of the Belt-Purcell Supergroup, southeastern British Columbia; Chapter 7: in Lydon, J.W., Hoy, T., Slack, J.F., and Knapp, M.E., eds., The Geological Environment of the Sullivan Deposit, British Columbia: Geological Association of Canada, Mineral Deposits Division, Special Publication No 1., p. 113-126.
Miller, F.K., Burmester, R.F., Miller, D.M., Powell, R.E., and Derkey, P.D., 1999, Digital geologic map of the Sandpoint 1o x 2o quadrangle, Washington, Idaho, and Montana: U.S. Geological Survey Open-File Report OF 99-144, scale 1:250,000 with report, 71 p.
Harrison, J.E., Griggs, A.B., and Wells, J.D., 1986, Geologic and structure maps of the Wallace 1o x 2o quadrangle, Montana and Idaho: U.S. Geological Survey Map I-1509-A, scale 1:250,000.
Griggs, A.B., 1973, Geologic map of the Spokane quadrangle, Washington, Idaho, and Montana: U.S. Geological Survey Map I-768, scale 1:250,000.
Winston, D. and Link, P.K., 1993, Middle Proterozoic rocks of Montana, Idaho and eastern Washington: The Belt Supergroup: in Link, P.K., ed., Middle and Late Proterozoic stratified rocks of the western U.S. Cordillera, Colorado Plateau, and Basin and Range province: in Reed, J.C., Jr., Bickford, M.E., Houston, R.S., Link, P.K., Rankin, D.W., Sims, P.K., and Van Schmus, W.R., eds., Precambrian: Conterminous U.S.: Boulder, Colorado, Geological Society of America, The Geology of North America, v. C-2, p. 467-517.
Mauk, J.L., and White, B.G., 2004, Stratigraphy of the Proterozoic Revett Formation and its control on Ag-Pb-Zn vein mineralization in the Coeur d'Alene district, Idaho: Economic Geology, v. 99, no. 2, p. 295-312.
Geographic coverageBenewah - Bonner - Boundary - Kootenai - Latah - Shoshone

Show this information as [XML] - [JSON]

AccessibilityFOIAPrivacyPolicies and Notices

Take Pride in America logoUSA.gov logoU.S. Department of the Interior | U.S. Geological Survey
URL: http://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=IDY2n;0
Page Contact Information: Peter Schweitzer