Field Guide; North Moccasin and Judith Mountains

Click for route map

Route

Start point

Lewistown, Montana

End point

Lewistown, Montana

Roads

U.S. 91, Montana 236

Total distance

103.4 miles

Geology

Summary

The emphasis of this field trip is to examine gold mineralization hosted in karsts breccias at the Kendall mining district and the relationship between intrusives, Paleozoic sedimentary rocks and mineralization in the Judith Mountains.

Key Lithologic Features

  • Telegraph Creek Formation
  • Eagle Formation
  • Niobrara Formation
  • Carlile Shale
  • Greenhorn Formation
  • Mowry Shale
  • Thermopolis Shale
  • Kootenai Formation
  • Morrison Formation
  • Ellis Formation
  • Kibbey Formation
  • Heath Formation
  • Ellis Group
  • Gold Hill intrusive
  • Crystal Peak intrusive
  • Cambrian limestone
  • Fall River Sandstone
  • Madison Group Limestone

Structures

Landforms

Other Features

  • Kendall Gold mine
  • Maginnis mine
  • Tail Holt mine
  • Giltedge mine
  • Spotted Horse mine
  • Cumberland mine

Reference

Garverich, M.R., 1991, Field Guide; North Moccasin and Judith Mountains, in Baker, D.W., and Berg, R.B., eds., Guidebook of the central Montana alkalic province: Geology, ore deposits and origin , Montana Bureau of Mines and Geology Special Publication 100, p. 175-184.

Availability

Out of print; can be photocopied for a fee. For more information, see this publication's record at the MBMG .