Nancy Group, Boulder Co., Colorado, USA
|Latitude & Longitude (WGS84):||40° 1' 8'' North , 105° 16' 39'' West|
|Latitude & Longitude (decimal):||40.01889,-105.27750|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
COLO BOM 1943 LIST
Commodities (Major) - Gold; (Trace) - Silver
Development Status: Past Producer
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded at this locality.
6 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
0.0117 - 2.588 Ma
Age: Pleistocene (0.0117 - 2.588 Ma)
Description: Reddish-brown pebbly to bouldery well stratified alluvium along perennial streams and sandy to clayey alluvium along intermittent streams. Well developed Brown soil profile underies surface of deposit. Terrace surface is 70 feet (21.5 m) above major stre
Reference: Colton, Roger B. Geologic Map of the Boulder-Fort Collins-Greeley area, Colorado . U.S. Geological Survey Geologic Investigations Series I-855-G. 
66 - 100.5 Ma
|Pierre Shale--Middle unit|
Age: Late Cretaceous (66 - 100.5 Ma)
Stratigraphic Name: Pierre Shale
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. 
201.3 - 252.17 Ma
|Mesozoic sedimentary rocks|
Age: Triassic (201.3 - 252.17 Ma)
Lithology: Sedimentary rocks
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.