Iron Cap Mine, Landsman Camp (Landsman group), Aravaipa, Santa Teresa Mts, Aravaipa District, Graham Co., Arizona, USA
|Latitude & Longitude (WGS84):||32° 58' 37'' North , 110° 19' 52'' West|
|Latitude & Longitude (decimal):||32.9769444444, -110.331111111|
|Other regions containing this locality:||Sonoran Desert, North America|
A former surface and underground Pb-Zn-Ag-Cu-Au-Fluorspar mine located in sec. 19, T5S, R20E, 2 miles NE of Aravaipa, ½ mile N of Landsman Camp, and near the head of Arizona Gulch, in the foothills of the Santa Teresa Mountains, at an altitude of approximately 5,000 feet, on private land.
Mineralization is a vein deposit hosted in the Horquilla Formation and the Pinkard Formation. Some veins occur in faults between formations. Others are wholly in limestone beds. Veinlets contain irregular lenses and pods of ore. An associated rock unit is the Copper Creek Granodiorite. Ore control was faults and ore concentration was in broad, low-plunging anticlines. No alteration noted.
The mineralized zones occur in the lower tunnel of this mine. The most westerly zone strikes N70W, and its dip, which varies, averages about 40º to the N. The other zone strikes N85W and is vertical from the surface to 4 feet below the upper tunnel, where it assumes a dip of of 40º to the N. The upper tunnel vein may be a fissure that branches from the lower tunnel vein where the break in dip occurs. Steeply dipping post-mineral faults of north- to NW-ward strike intersect the thrust fault below the lower tunnel. The lower tunnel ore zones occur near the base of a limestone thrust block. Ores generally not oxidozed. Oxidztion of the ore zones within the district is probably shallowest at these workings, where it extends only a few feet below the surface.
Area structures include low-angle, reverse faults between Horquilla and Pinkard and block faulting trending NNW. Regional trends: minor Pre-Cretaceous E- and NE-trending folds and major Post-Cretaceous NNW-trending faults.
The princpal workings are accessible through two entries. The upper entry, 149 feet vertically above the lower one, is a tunnel driven west on a vein for 110 feet. Development from this drift tunnel consists of a 20-foot raise and crosscuts into both walls of the vein. The lower entry, a 630 foot crosscut, intersects a vei 430 feet SW of its portal. A drift extends weserly for 200 feet from this intersection. From the drift, some stoping has been done and a winze 20 feet deep has been sunk. A raise from the top of the stope connects with the upper workings. Another drift from a point in the crosscut 75 feet SW of the vein intersection extends 56 feet SE-ward. Also, a large glory hole in the limestone formation.
Production not given. Assay showed 1-19% Pb, 1-35% Zn, less than 1.7 oz/ton Ag, and a trace of Cu, Au.
|Quaternary0 - 2.588 Ma||Quaternary sedimentary rocks|
|Mesozoic - Paleozoic66 - 541 Ma||Paleozoic-Mesozoic sedimentary|
|Paleozoic252.17 - 541 Ma||Paleozoic sedimentary rocks|
References for regional geology:
Data provided by Macrostrat.org
Garrity, C.P., and Soller, D.R.,. Database of the Geologic Map of North America: adapted from the map by J.C. Reed, Jr. and others (2005). U.S. Geological Survey Data Series 424 .
USGS compilers. State geologic map data. State Maps.
Geological Survey of Canada. Generalized geological map of the world and linked databases. doi:10.4095/195142. Open File 2915d.
26 valid minerals.
Ross, C.P. (1925a), Geology and ore deposits of the Aravaipa and Stanley mining districts, Graham County, Arizona, USGS Bull. 763.
Denton, T.C. (1947), Aravaipa lead-zinc deposits, Graham County, Arizona, U.S. Bureau of Mines Report of Investigation 4007: 5, 6.
Galbraith, F.W. (1947), Minerals of Arizona, Arizona Bureau of Mines Bull. 153: 17.
Wilson, E.D., et al (1950), Arizona zinc and lead deposits, part I, Arizona Bureau of Mines Bull. 156: 56-58.
Simons, F.S. & E. Munson (1963), Johannsenite from the Aravaipa mining district, Arizona, American Mineralogist: 48: 1154-1158.
Simons, F.S. (1964), Geology of the Klondyke quadrangle, Graham and Pinal Counties, Arizona, USGS PP 461: 134.
Elevatorski, E.A. (1971), Arizona Department of Mineral Resources (ADMR), Arizona Fluorspar: 19.
Elevatorski, E.A. (1978), Arizona Industrial Minerals, Arizona Department of Mineral Resources, Minerals Report No. 2: 33.
Reiter, B.E. (1981), Controls on lead-zinc skarn mineralization, Iron Cap mine area, Aravaipa district, Graham County, Arizona, in C. Stone and J.P. Jenney (editors), Arizona Geological Society Digest: 13: 117-125.
Phillips, K.A. (1987), Arizona Industrial Minerals, 2nd. Edition, Arizona Department of Mines & Minerals Mineral Report 4, 185 pp.
Wilson, W.E. (1988), The Iron Cap Mine, Mineralogical Record: 19(2): 81-87.
Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 228, 245, 258, 263, 270, 288, 311, 377.
Grant, Raymond W., Bideaux, R.A., and Williams, S.A. (2006) Minerals Added to the Arizona List 1995-2005: 4.
USGS Cobre Grande Min Quadrangle map.
Arizona Department of Mineral Resources Brushy group file.
Arizona Department of Mineral Resources U file.
U.S. Bureau of Land Management Mining Claims Lead File #6032 (Jul, 1980).
MRDS database Dep. ID #10039448, MRDS ID #M050094; and Dep. ID #10161369, MAS ID #0040090178.