Lavender Open Pit Mine (Lavender pit), Bisbee, Warren District, Mule Mts, Cochise Co., Arizona, USA
|Location is approximate, based on center of defined region.|
|Latitude & Longitude (WGS84):||31° 25' 54'' North , 109° 53' 54'' West|
|Latitude & Longitude (decimal):||31.43194,-109.89861|
A former large output surface Cu-Au-Ag-Zn-Gemstone mine located in the SW¼ sec 10, NW¼NW¼ sec. 15, T.23S., R.24E. Bisbee 7.5 minute topo map), NW edge of Lowell, on private land. Produced 1954-1974. Owned by the Phelps Dodge Corp.
Mineralization is a porphyry copper deposit with a blanket ore body of low grade disseminated chalcocite with local spots of other copper and zinc sulfides in a blanket deposit in a brecciated intrusive porphyry plug adjoining altered Paleozoic limestones along the Dividend fault. Ore concentration was bornite replacing pyrite. An associated rock unit is the Sacramento Hill Stock. Low-grade copper ores. The turquoise was a hard, deep blue, sometimes found in a matrix of hard red mineral (cuprite?).
Local structures include pre-mineralization faulting and tilting. Main fault directions are N10W to N40E and S30W to N50W. The Dividend Fault "horsetails", its strike is N20E and it dips S70. Displacement along the fault is about 500 feet. This fault Separates the Sacramento/Lavendar pit and the extension to the east (Cochise project).
Workings are a huge open pit 914.4 meters long (1,219.2 meters overall length) by 457.2 meters wide and over 750 feet deep (more than 15, 50 foot high benches). Some 75 million tons of ore were produced from 1954 to 1970.
The current highway follows the Dividend Fault. Large bulk mineable, low-grade porphyry copper ore. There is substantial supergene ground water enrichment at the base of the leach cap. There is a substantial reserve of Cu ore. The chalcocite blanket was nearly mined out but recent exploration (1989-1991) has identified several high-grade polymetallic targets in the Mississippian limestone. Future open pit mining would use electro-winning solution leach processing methods.
36 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
|Campanian - Oxfordian|
72.1 - 163.5 Ma
|Cretaceous to Late Jurassic sedimentary rocks with minor volcanic rocks|
Age: Mesozoic (72.1 - 163.5 Ma)
Stratigraphic Name: Temporal Formation; Bathtub Formation; Sand Wells Formation; Fort Crittenden Formation; McCoy Mountains Formation
Description: Sandstone and conglomerate, rarely forms prominent outcrops; massive conglomerate is typical near base of unit and locally in upper part. These deposits are nonmarine except in southeastern Arizona, where prominent gray marine limestone (Mural Limestone) forms the middle of the Bisbee Group. Sandstones are typically medium-bedded, drab brown, lithic-feldspathic arenites. Includes Bisbee Group (largely Early Cretaceous) and related rocks, Temporal, Bathtub, and Sand Wells formations, rocks of Gu Achi, McCoy Mountains Formation, and Upper Cretaceous Fort Crittenden Formation and equivalent rocks. (80-160 Ma)
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. 
Bryant, D.G. & H.E. Metz (1966), Geology and ore deposits of the Warren mining district, in S.R. Titley and C.L. Hicks (editors), Geology of the porphyry copper deposits, southwestern North America, University of Arizona Press, Tucson: 191, 197-199.
Keith, Stanton B. (1973), Arizona Bureau of Mines Bull. 187, Index of Mining Properties in Cochise County, AZ: 88 (Table 4).
Blair, Gerry (1992), The Rockhound's Guide to Arizona: Helena, MT, Falcon Press.
Niemuth, N.J. & K.A. Phillips (1992), Copper Oxide Resources, Arizona Department of Mines & Minerals Resources Open File Report 92-10: 5 (Table 1).
Graeme, R. (1993), Bisbee revisited, Mineralogical Record: 24: 421-436.
Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 160, 162, 203, 220, 245, 344, 386, 388.
Singer, D.A., Berger, V.I., and Moring, B.C. (2005): Porphyry Copper Deposits of the World: Database, Map, and Grade and Tonnage Models. USGS Open-File Report 05-1060.
Grant, Raymond W., Bideaux, R.A., and Williams, S.A. (2006) Minerals Added to the Arizona List 1995-2005: 5.
Arizona Bureau of Mines files.
MRDS database Dep. ID file #10046238, MRDS ID #M241102; and, Dep. ID #10137191, MAS ID #0040030044.