Geis Mine (Red Metal Claim group; Gies Mine; Elk Peak project; Bertha claim group), Cone Butte Sub-District, Warm Springs District (Gilt Edge District; Gold Hill District; Maiden District), Fergus Co., Montana, USA
|Latitude & Longitude (WGS84):||47° 13' 17'' North , 109° 9' 44'' West|
|Latitude & Longitude (decimal):||47.22132,-109.16219|
|Köppen climate type:||Dfb : Warm-summer humid continental climate|
A group of 11 patented claims between Armells Creek and Ford Creek about 3 miles NW of old Fort Maginnis.
Mineralization is a Ag-Pb-Zn deposit along the contact between limestone and syenite porphyry.
Property is developed by adits and shafts.
Average grade of 13.7g/t, but high grade to 13,714 g/t.
Unknown of composition - (Ag,Cu)9(As,Sb)(Te,S)6
38 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
66 - 100.5 Ma
|Mesozoic sedimentary rocks|
Age: Late Cretaceous (66 - 100.5 Ma)
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. 
100.5 - 113 Ma
|Thermopolis and Fall River Formations|
Age: Early Cretaceous (100.5 - 113 Ma)
Stratigraphic Name: Thermopolis Shale; Fall River Formation
Description: Thermopolis Formation (Kt): Dark gray to black shale with subordinate siltstone beds. Middle part of formation contains one or more thin sandstone beds with chert pebble horizons where Muddy Sandstone is not present. Offshore marine. Thickness as much as 305 m (1,000 ft). Fall River Formation (Kfr): Gray and brown, fine- to medium-grained, quartzose sandstone with thin interbeds of dark gray shale. Nearshore marine. Thickness as much as 70 m (1,214 ft).
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052.