Location
Low hills on both sides of Sonoita Creek south of the SantaRita Mountains, Tps. 21 and 22 S., Rs. 14 and 15 E.
Topographic Maps
Mount Wrightson and Nogales 15-minute quadrangles.
Geologic Maps
Drewes, 1971a, Geologic map of the Mount Wrightson quadrangle, Santa Cruz and Pima Counties, Arizona, scale 1:48,000.
Wilson, Moore, and O'Haire, 1960, Geologic map of Pima and Santa Cruz Counties, scale 1:375,000.
Extent
Three minor placers are on the west flank of the Patagonia Mountains in the Tyndall, Palmetto, and Harshaw districts. The only information found relates to the location of the placers given by Schrader (1915, p. 220, 279) for the Tyndall and Harshaw districts, and by Wilson (1961, p. 84), for the Palmetto district.
The placers in the Tyndall district are found in the gravels in the open basin at the head of the tributary to Ash Canyon in the SW 1/4 of sec. 35 and on both sides of the township line between Tps. 21 and 22 S., R. 14 E. (Mount Wrightson quadrangle).
The placers in the Harshaw district are in Quaternary gravels on a mesa southeast of the junction of Sonoita Creek and Alum Canyon in sees. 13 and 24, T. 22 S., R. 15 E. (Mount Wrightson quadrangle).
The placers in the Palmetto district are in Three R Canyon 2 1/2 miles northwest of the Three R mine in sec. 27, T. 22 S., R. 15 E. (Nogales quadrangle); the placers were worked for 1 month in 1927 and abandoned.
Production History
The Tyndall and Palmetto deposits have had no recorded production during the 20th century, and are relatively unknown. A small production was made from the Palmetto district.
Source
The detrital gold was probably eroded from small gold-bearing veins in the vicinity of the placers.
Literature
Schrader, 1915: Tyndall district—location. Harshaw district—location; accessory minerals; placer-mining activity.
Wilson, 1961: Tyndall district—quotes Schrader. Harshaw districtquotes Schrader. Palmetto district—location; placer-mining activity in 1927.
