Ledge Prospect

The Ledge prospect is three-eighths of a mile southeast of the Gray camp. It is on a 50 foot siliceous ledge which dips steeply to the south and is traceable for about 1,000 feet and in this distance cuts across the contacts of quartz monzonite with diorite and diorite with granite porphyry. This ledge is opened at intervals by several pits and appears to be a sheared dike of the granite porphyry, for soon after passing into the main area of this area it terminates or becomes lost and the vein matter of the ledge, which is largely quartz with seemingly altered feldspar, resembles the granite porphyry.

The metallic minerals, consisting of copper and lead sulfides which begin 4 or 5 feet below the surface, are concentrated in the fractures and shear-plane faces of the ledge, mostly in association with the quartz².

Ownership

unclear

Location

31.42056,-110.80694¹⁰

Mineral Products

copper and iron sulfides¹⁰

References

1. Mineral Appraisal of Coronado National Forest, Part 12, Santa Rita Mountains Unit, MLA11-94 (1994). SR 591-609
   http://repository.azgs.az.gov/sites/default/files/dlio/files/nid1813/usbm_mla_011-94.pdf
2. Mining in the Santa Rita and Patagonia Mountains of Arizona, U.S. Department of Interior, 1915. Republished 2014 by Kerby Jackson.
3. Mike Bertram, 11/21/23
4. USGS Mineral Resources Data System - possibly using NAD72 (https://mrdata.usgs.gov/mrds/map-commodity.html#home)
5. Index of Mining Properties in Santa Cruz County by Staton B. Keith, bulletin 1991, Arizona Geological Survey, 1975
6. Geology of the Three R Mine, Palmetto Mining District, Santa Cruz County, Arizona by Paul Handverger, MS thesis 1963, University of Arizona
7. https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=10046338
8. https://azdeq.gov/Three-R-Mine
9. https://tucson.com/news/local/three-r-mine-contributed-to-arizonas-rep-for-copper-production/article_2a25e1e1-7280-5fd5-be97-a40732a39b1b.html
10. mindat.org