LOCATION GARZONA AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Lithic Haplocambids
TYPICAL PEDON: Garzona extremely stony loam - rangeland. (Colors are for dry soil unless otherwise noted.) 80 percent of the surface is covered by stones, cobble, and gravel.
A--0 to 2 inches; light brown (7.5YR 6/4) extremely stony loam, brown (7.5YR 4/4) moist; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; noneffervescent; 65 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (1 to 3 inches thick)
Bw1--2 to 6 inches; brown (7.5YR 5/4) very gravelly loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; noneffervescent; 5 percent cobble and 40 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (2 to 6 inches thick)
Bw2--6 to 15 inches; brown (7.5YR 5/4) extremely cobbly loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, sticky and plastic; few very fine roots; many very fine irregular pores; faint clay films as coatings and bridges; noneffervescent; 10 percent stones, 50 percent cobble and 15 percent gravel; slightly alkaline (pH 7.4); abrupt wavy boundary. (7 to 11 inches thick)
2R--15 inches; basalt.
TYPE LOCATION: Pima County, Arizona; about 18 miles northeast of Ajo; about 7300 feet east and 20,700 feet north of the southwest corner of T. 11 S., R. 3 W. (unsectionized area)
RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of the soil moisture control section during July - September and December - February. Driest during May and June. Typic aridic soil moisture regime.
Soil temperature - 66 to 72 degrees F.
Depth to bedrock - 10 to 20 inches
Organic Matter - less than 1 percent in the upper 6 inches
Rock fragments: 75 to 90 percent of the surface is covered by stones, cobble, and gravel. Rock fragments average more than 35 percent in the particle-size control section.
A horizon
Hue: 10YR, 7.5YR
Value: 5 or 6, dry or moist
Chroma: 2, 3, or 4, dry or moist
B horizon
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: loam, clay loam (10 to 30 percent clay)
COMPETING SERIES: These are the Cupel (AZ), Garr (I)(NV), Metanob (I)(CA), Pacific Mesa (CA), Pulsipher (NV), and Tufon (I)(CA)series. These soils are moist in some part of the soil moisture control section for less than 20 days cumulative between July and September. In addition, Garr and Pacific Mesa soils are calcareous throughout. Garr, Metanob, and Tufon soils are inactive.
GEOGRAPHIC SETTING: Garzona soils are on hills and mountains. Slope ranges from 15 to 65 percent. Elevations range from 2800 to 4100 feet. They formed in alluvium from basalt and other pyroclastic rocks. The mean annual precipitation is 10 to 13 inches occurring as summer thunderstorms and gentle winter rain. Mean annual air temperature is 65 to 70 degrees F. The frost-free period is 180 to 270 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Akela and Winkel soils. Akela soils do not have cambic horizons and are lower on the landscape. Winkel soils have a petrocalcic horizon and are lower on the landscape.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; rapid runoff; moderate permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation is mainly bush muhly, littleleaf paloverde, slender janusia, Arizona cottontop, Slim tridens, Mormon-tea, Whitethorn, desert thorn, twinberry and ocotillo.
DISTRIBUTION AND EXTENT: Southern Arizona. This series is moderately extensive. MLRA 40.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Gila Bend-Ajo Area, Arizona, Parts of Maricopa and Pima Counties; 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 2 inches (A horizon)
Cambic horizon - the zone from 2 to 15 inches (Bw1, Bw2 horizons)
Lithic contact - the boundary at 15 inches (2R horizon)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
Revised for the correlation of AZ661, 12/2008, WWJ.