Guide to the Benbow Area
Route
Start point
Dean, Montana at the intersection of Montana 419 and U.S. Forest Service Road 1414 (Benbow Road)
End point
Dean, Montana at the intersection of Montana 419 and U.S. Forest Service Road 1414 (Benbow Road)
Roads (and Trails)
Montana 419, Benbow Road
Total distance
18.53 miles
Geology
Summary
The Benbow area (named for T.C. Benbow, who first discovered chromite there) is at the east end of the exposed Stillwater Complex....Most of the localities described...are in the Ultramafic series....The features emphasized at these localities include the nature of the cyclic units, pegmatoids associated with chromite seams, evidence for slumping anbd slope instability in the Stillwater magma chamber, lateral persistence of some of the chromite seams, and the unconformity between the Banded series of the Stillwater Complex and overlying Cambrian limestone.
Key Lithologic Features
- Paleozoic and Mesozoic sedimentary rocks
- layered rocks of the Stillwater Complex, including rocks and associated chromitite seams in the Peridotite zone of the Ultramafic Series, and rocks of the Banded Series
Structures
- Benbow Fault Zone
- unconformity between the Stillwater Complex and the overlying Cambrian limestones
Landforms
Other Features
Reference
Lipin, B.R., Page, N.J., Zientek, M.L., Carlson, R.R., Loferski, P.J., Nicholson, S.W., and Moring, B.C., 1985, Guide to the Benbow Area,
in Czamanske, G.K., and Zientek, M.L., eds.,
The Stillwater Complex, Montana: Geology and Guide : Montana Bureau of Mines and Geology Special Publication 92, p. 125-146.
Availability
Order from the Montana Bureau of Mines and Geology. Search for
this publication's record at the MBMG for ordering information.
