Pg. 106 (fig. 1). Sugarloaf series. Comprises (ascending) pink to gray rhyolite, thickness 140 feet; soft gray rhyolite tuff, 80 feet; brownish red rhyolite, 30 feet; gray rhyolite tuff, 20 feet; and black to gray, vesicular augite dacite, 220 feet. Overlies Rhyolite Canyon series (new). Age is Cenozoic.
Section measured in Rhyolite Canyon, Chiricahua National Monument, Cochise Co., southeastern AZ.

Source: US geologic names lexicon (USGS Bull. 1200, p. 3761).

Pg. 90-93, pls. 5, 12. Sugarloaf quartz latite. Divided into rhyolitic and andesitic members. Rocks generally light-gray or dense-white, with slightly pinkish-gray hue on fresh fractures. In some areas, contains phenocrysts of biotite, quartz, and chalky feldspar that range up to 2 mm and average 1 mm in length. Groundmass is aphanitic. Estimated thickness at Sugarloaf Hill about 1,500 feet. Nearly all contacts with other formations are faults. Accordingly, a complete section would be still thicker. At no other point in area is a thickness of more than 500 feet exposed. Age is Late Cretaceous or early Tertiary. Report includes geologic map.
Type locality: at Sugarloaf Hill, in sec. 8, T. 20 S., R. 25 E., about 1 mi southeast of Gleeson, central Cochise Co., southeastern AZ. Recognized in Courtland-Gleeson area.

Source: US geologic names lexicon (USGS Bull. 1200, p. 3761); supplemental information from GNU records (USGS DDS-6; Denver GNULEX).

Correlated (correlation chart, fig. 2) with known Upper Cretaceous rocks. Is in the Dragoon Pedregosa basin. Age changed from Cretaceous or Tertiary to Late Cretaceous age.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Occurs in and near southeast side of Dragoon Mountains, Cochise Co, AZ in Pedregosa basin. Is comparable in lithology to upper part of Bronco Volcanics (Upper Cretaceous). Part or all of Sugarloaf is probably equivalent to at least the upper rhyodacitic part of Salero Formation (Upper Cretaceous). K-Ar age of 72.8 +/-2.5 m.y. for biotite from welded tuff from type locality (R. F. Marvin, H. H. Mehnert, and V. Merritt, written communication, 1969). Is Late Cretaceous on basis of isotopic dating.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Samples collected from Sugarloaf Quartz Latite in the Dragoon Mountains, AZ. Age is Late Cretaceous.
(1) Sample from andesite member. K-Ar age on hornblende 33.3 +/-2.6 Ma. Sample locality: Lat. 31 deg. 48 min. N., Long. 109 deg. 47 min. W.
(1) Sample from welded tuff. K-Ar age on biotite 72.8 +/-2.8 Ma. Sample locality: Lat. 31 deg. 43 min. N., Long. 109 deg. 47 min. W.

Source: Modified from GNU records (USGS DDS-6; Denver GNULEX).

Lower member shown as Campanian age of Late Cretaceous and andesite member as of Oligocene age. Correlation chart. Is in the Dragoon Mountains, Cochise Co, AZ in the Pedregosa basin.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Dacitic lavas defined by Gilluly (1956) as the upper member or andesitic member of the Sugarloaf are now known to be middle Tertiary age and are absent at the type locality at Sugarloaf Hill in Cochise Co, AZ in the Pedregosa basin. The Sugarloaf is revised to include only the lower rhyolitic member of Gilluly. The lower tuff is Upper Cretaceous (Laramide). The dacite lavas not well understood and are therefore left unnamed and removed from the Sugarloaf.

Source: GNU records (USGS DDS-6; Denver GNULEX).