St. Louis Mine, Greaterville district

The St. Louis mine is about ¾ miles west of Greaterville, at the southeast base of Granite Mountain, on the east side of St. Louis Gulch, near its junction with Hughes Gulch, at an elevation of 5,495 feet. It was located in 1874and was developed in 1886 by a 75 foot shaft and drifts. At that time it shipped ore to the El Paso smelter, some of which it is said to have averaged 40% of lead and 75 oz. of silver and about 12 oz. in gold to the ton. It is on a compound vein or lode about 8 feet wide, composed of quartz veins and numerous small rhyolite dikes and contained in a northeast-southwest shear zone about 800 feet wide and 3,000 feet long, in altered shales, hornfels, and silicified dolomitic limestone. This zone lies at the southeast base of Granite Mountain, and the intrusion of the granite porphyry forming the mountain deformed and metamorphosed the sediments. The veins in the lode are linked and form a stockwork, The load dips 45° SE, away from the mountain, about parallel with the inclosing rocks and its dip seems to flatten with depth on receeding from the mountain. Almost throughout the extent of the lode occur numerous mineral-bearing quartz stringers and it is asserted that practically all the lode material is good milling ore.

Near the middle of the lode is a 2 to 3 foot band, composed almost entirely of quartz, in which the metallic minerals are more concentrated, and with a little sorting this ore becomes of fair smelting grade.

The metallic minerals are argentiferous galena and sphalerite, with some pyrite and chalcopyrite. They occor also in small quantities at the surface and in iron-stained croppings, where fairly large nuggets of native gold are said to have been found.

On the Fulton claim, south of St. Louis, the lode is about 20 feet wide and is opened by a 60 foot and a 100 foor shaft. Here it shows considerable surface mineralization, which, however, is less concentrated than on the St. Louis ground².

Mining District and Mines

Greaterville District

Location

-110.76429, 31.75902 (WGS84), elevation 1,675m⁴

Mineral Products

Pb, Ag, Au, Zn, Cu, Mo, Fe⁴

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. mindat.org
4. USGS Mineral Resources Data System - possibly using NAD72 (https://mrdata.usgs.gov/mrds/map-commodity.html#home)
5. Index of Mining Properties in Pima County by Stanton B. Keith, bulletin 189, Arizona Geological Survey, 1974