Altyn limestone (MTpCAa;0)

State	Montana
Name	Altyn limestone
Geologic age	Proterozoic \| Mesoproterozoic
Original map label	pCa
Primary rock type	carbonate
Secondary rock type	quartzite
Other rock types	meta-argillite
Lithologic constituents	Major Sedimentary > Carbonate (Bed)Mostly dolomite, plus lesser limestone, each weakly metamorphosed. Minor Metamorphic > Metasedimentary > Metaclastic > Argillite (Greenschist) Metamorphic > Metasedimentary > Metaclastic > Quartzite (Greenschist)
Map references	Ross, P.R., Andrews, D.A., and Witkind, I.J., 1955, Geologic map of Montana: U.S. Geological Survey, 2 sheets, scale 1:500,000.
Unit references	Wilde, E.M., and Porter, K.W., 2000, Geologic map of the Roundup 30' X 60' quadrangle, central Montana: Montana Bureau of Mines and Geology Open File Report 404, scale 1:100,000. Harrison, J.E., Whipple, J.W., and Lidke, D.J., 1998, Geologic map of the western part of the Cut Bank 1° x 2° quadrangle, northwestern Montana: U.S. Geological Survey Miscellaneous Geologic Investigations Series Map I-2593, scale 1:250,000. [http://pubs.er.usgs.gov/publication/i2593] Mudge, M.R., 1977, General geology of Glacier National Park and adjacent areas, Montana: Canadian Society of Petroleum Geologists Bulletin, v. 25, no. 4, p. 736-751. Harrison, J.E., 1972, Precambrian Belt basin of northwestern United States--Its geometry, sedimentation and copper occurrences: Geological Society of America Bulletin, v. 83, no. 5, p. 1215-1240. Whipple, J.W., 1992, Geologic map of Glacier Park, Montana: U.S. Geological Survey Miscellaneous Investigations Series Map I-1508-F, 1 sheet, scale 1:100,000. [http://pubs.er.usgs.gov/publication/i1508F] Whipple, J.W., Connor, J.J., Raup, O.B., and McGimsey, R.G., 1984, Preliminary report on the stratigraphy of the Belt Supergroup, Glacier National Park and adjacent Whitefish Range, Montana, in McBane, J.D., and Garrison, P.B., eds., Northwest Montana an Earhart, R.L., Mudge, M.R., and Connor, J.J., 1984, Belt Supergroup lithofacies in the Northern Disturbed Belt, northwest Montana, in McBane, J.D., and Garrison, P.B., eds., Northwest Montana and adjacent Canada--Montana Geological Society 1984 Field Con
Geographic coverage	Flathead - Glacier