Mineral Resources On-Line Spatial Data
Mineral Resources > Online Spatial Data > Geology > by state > Montana
|Geologic age||Proterozoic | Mesoproterozoic|
|Original map label||pCsi|
|Comments||An obsolete stratigraphic name, now replaced by Helena Formation. Apparently only used in MT originally within Glacier National Park.|
|Primary rock type||carbonate|
|Secondary rock type||quartzite|
|Other rock types||meta-argillite|
Sedimentary > Carbonate (Bed)Weakly metamorphosed limestone and dolomite.
Metamorphic > Metasedimentary > Metaclastic > Argillite (Greenschist)
Metamorphic > Metasedimentary > Metaclastic > Quartzite (Greenschist)
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.
Lopez, D.A., 2001, Geologic map of the Chester 30' x 60' quadrangle, north-central Montana: Montana Bureau of Mines and Geology Open File Report 445, 4 p., scale 1:100,000.
|Geographic coverage||Flathead - Glacier|
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