Location:
East flank of the Patagonia Mountains, T. 23 S., R. 16 E. (unsurveyed).
Topographic Map
Lochiel 15-minute quadrangle.
Geologic Map
Wilson, Moore, and O'Haire, 1960, Geologic map of Pima and Santa Cruz Counties, scale 1:375,000.
Access
From Nogales, about 5 miles northeast on State Highway 82 to junction with light-duty road at the Santa Cruz River; from there, 10 miles east across Patagonia Mountains to dirt roads that lead to placers in Mowry Wash.
Extent
Small placers are found in gravels of Mowry Wash and some of its tributaries. Schrader (1915, p. 348) locates four areas where gold was recovered from the gravels: at the east edge of the Quajolote Flat in gravels about 5 feet thick (in Providencia Canyon, near the Four Metals mine); near the head of Mowry Wash in the gravels in a southside tributary (near the old Winifred mine); and in two northside tributaries southeast of Mowry.
Placers were also found in Quajolote Wash downstream from the old Mowry smelter; this wash is not named on the topographic map. The gold recovered from the Patagonia placers is generally associated with black sand and in size is generally less than 0.1 inch diameter. One 2-ounce nugget and several smaller nuggets were found.
Production History
The placers in the Patagonia district have a recorded production of about 100 ounces, about equal to that of the Oro Blanco district, although they probably were not so important in the early history of the region.
Source
The detrital gold was apparently freed by erosion of silver, lead, and copper ores that contain very minor amounts of gold. The host rocks for the ore bodies in the drainage area of Mowry Wash are Precambrian quartz monzonite at the Four Metals mine and monzonite and Carboniferous limestone at the Mowry mine.
Literature
Mining and Scientific Press, 1908: Reports placer-mining activity; production per man per month.
Schrader, 1915: Location; placer-mining activity; average yield per day per man; production.
Wilson, 1961: Quotes Schrader; adds information on placer mining in 1933; size of gold particles.
