Henderson Mine, Dailey District (Jones Pass District), Clear Creek Co., Colorado, USA
|Latitude & Longitude (WGS84):||39° 46' 8'' North , 105° 50' 57'' West|
|Latitude & Longitude (decimal):||39.76889,-105.84917|
|Köppen climate type:||Dfc : Subarctic climate|
The Henderson ore deposit is located 3000 feet beneath the summit Red Mountain, about 10 miles west of Empire in the Dailey (Jones Pass) district. Access is from U.S. Highway 40 at Berthoud Falls.
The Henderson mine, which has produced molybdenum since 1976 (the deposit was discovered in 1964), is owned by Freeport-McMoRan. It is North America’s largest producer of primary molybdenum source. 2007 production was 40 million pounds of molybdenum.
The Henderson orebody is a blind deposit of about 300 mt (>0.2%) located deeper in the intrusive complex beneath the Urad orebody. Urad produced molybdenum during World War 1 and then again from 1967 to 1974 when the orebody was exhausted.
Both the Urad and Henderson deposits are associated with the Red Mountain Intrusive Center. This is an intrusive complex with more than 20 identifiable pulses of magma. The Henderson orebody was produced from 3 intrusive centers, all of which are hosted within the Urad porphyry. The Henderson - Urad ore deposit is a classic "Climax type" porphyry Mo deposit and many of the genetic characteristics recognized at the Climax mine were applied here from the initial exploration phase onward. The geology is well summarized by Shannon, et al. (2004)
Mining has occurred on 3 levels: 8100, 7700 and 7210. As of 2011 production is solely from the 7210 level.
39 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 - 0.126 Ma
|Till of Pinedale age|
Age: Pleistocene (0.0117 - 0.126 Ma)
Description: Mostly nonsorted and nonstratified, subangular to subrounded boulders to granules in a silty sand matrix. Material less than 2 mm in diameter is estimated to be 20–40 percent of unit. This material consists chiefly of poorly sorted sand and ≤20 percent silt and ≤5 percent clay. Unit commonly forms large prominent, sharp-crested lateral and end moraines that are very bouldery and have distinct constructional morphology. Deposits in some areas have well-expressed knob-and-kettle topography. Surface soils have A/Cox profiles on moraines with narrow crests and A/Bw/Cox and A/Btj/Cox profiles on moraines with broad crests. Surface and near-surface O and E soil horizons are locally present. Cambic (Bw) and weak argillic (Btj) horizons are thin (10–40 cm) and commonly contain 1–5 percent more clay than the underlying till (<2 mm size fraction). Most of the biotite-rich granitic and gneissic clasts within the soil are unweathered, and disintegrated clasts are rare. Unit locally includes deposits of stratified drift, mass-movement and glacial deposits, undivided (Qmg), tills of the Satanta Peak and Triple Lakes advances of Benedict (1985), about 12–10 ka (Davis, 1988), till of Bull Lake age (Qtb), colluvium (Qc) and other mass-movement deposits, and valley-floor alluvium (Qva); locally may include till of pre-Bull Lake age. Radiocarbon (14C) and cosmogenic-exposure ages indicate that till of unit Qtp is about 30–12 ka (Nelson and others, 1979; Madole, 1986; Schildgen and Dethier, 2000; Benson and others, 2004, 2005). Subsurface deposits and locally some surface deposits of unit Qtp may be older than 30 ka, because uranium-series ages of travertine in the northern Yellowstone area suggest an early advance of Pinedale ice about 47–34 ka (Sturchio and others, 1994). Estimated thickness 1.5–30 m
Reference: Kellogg, K.S., Shroba, R.R., Bryant, Bruce, and Premo, W.R. Geologic Map of the Denver West 30' x 60' Quadrangle, North- Central Colorado. USGS Geologic Investigations Series 3000. 
1000 - 1600 Ma
|Granitic rocks of 1400-m.y. age group|
Age: Mesoproterozoic (1000 - 1600 Ma)
Description: Includes Silver Plume, Sherman, Cripple Creek, St. Kevin, Vernal Mesa, Curecanti, Eolus, and Trimble Granites or Quartz Monzonites; also, San Isabel Granite of Boyer (1962) and unnamed granitic rocks
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.