LOCATION GRANOLITE AZEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, thermic, shallow Typic Haplargids
TYPICAL PEDON: Granolite extremely gravelly sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; reddish brown (5YR 4/4) extremely gravelly sandy loam, dark reddish brown (5YR 3/4) moist; weak fine and medium platy structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; common to many very fine vesicular and tubular pores; 50 percent gravel, 15 percent cobble and 1 percent stones from igneous rock; noneffervescent; neutral; abrupt smooth boundary. (1 to 6 inches thick)
Bt1--2 to 7 inches; dark reddish brown (2.5YR 3/4) extremely gravelly sandy clay, dark reddish brown (2.5YR 2/4) moist; moderate fine and medium subangular blocky structure; hard, friable, very sticky and very plastic; few discontinuous faint clay coatings in root channels and/or pores; common fine and medium roots; few to common fine and very fine tubular pores; 55 percent gravel, 10 percent cobble from igneous rock; noneffervescent; neutral; clear wavy boundary. (4 to 7 inches thick)
Bt2--7to 16 inches; weak red (10R 4/4) extremely gravelly sandy clay, dusky red (10R 3/4) moist; moderate fine and medium subangular blocky structure; very hard, firm, very sticky and very plastic; few patchy clay coatings in root channels and/or pores; many continuous faint pressure faces on vertical and horizontal faces of peds; few to common fine and medium roots; few to common very fine and fine tubular pores; 60 percent gravel and 10 percent cobble from igneous rock; noneffervescent; neutral; abrupt wavy boundary. (5 to 9 inches thick)
2Crtk--16 to 19 inches; light gray (5YR 7/1) weathered rhyolite, light gray to gray (5YR 6/1) moist; common patchy prominent red (2.5YR 4/6) clay films on fractured rock; common patchy distinct strongly effervescent calcium carbonate coats on fractured faces of rocks; very few to few coarse roots in fractures; gradual wavy boundary. (3 to 20 inches thick)
2Crk--19 to 24 inches; light gray (5YR 7/1) weathered rhyolite, light gray to gray (5YR 6/1) moist; common patchy distinct strongly effervescent calcium carbonate coats on fractured faces of rock.
2R--24 inches; rhyolite.
TYPE LOCATION: Pima County, Arizona; 2600 feet west and 1400 feet north of the southeast corner of Section 20, T.14 S., R.10 E. Latitude of 32 degrees, 11 minutes, 37 seconds N., Longitude of 111 degrees, 20 minutes, 48 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during July-September and December-March. Driest during May and June. Typic aridic soil moisture regime.
Soil Temperature: 68 to 72 degrees F.
Depth to Bedrock: 10 to 20 inches
Calcium carbonate: May have coatings on bedrock and weak effervescence in the lower part of the solum.
Organic Matter: .5 to 1 percent
Rock Fragments: 35 to 85 percent gravel and/or cobble
Clay Content: Average 35 to 50 percent and less than 25 percent very coarse and coarse sand in the control section
Reaction: Neutral or slightly alkaline
A horizon
Hue: 5YR, 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Bt horizon
Hue: 10YR, 7.5YR, 5YR
Value: 3, 4, or 5, dry or moist
Chroma: 3, 4, or 6, dry or moist
Texture: sandy clay, clay, clay loam
COMPETING SERIES: This is the Gran (AZ) series. Gran soils do not have calcium carbonate, rock fragments readily break to coarse and very coarse sand with slight to medium pressure, and formed in decomposed granite.
GEOGRAPHIC SETTING: The Granolite soils are on hills, mountains or pediments. Slope is 2 to 65 percent. They formed in slope alluvium, derived dominantly from rhyolite and other acid igneous rock including to a lesser extent hard granitic material. Elevation ranges from 2000 to 3600 feet. The mean annual precipitation is 10 to 13 inches. The mean annual air temperature is 67 to 70 degrees F., and the frost-free period is about 240 to 260 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anklam, Lajitas and Pantano soils. Lajitas soils do not have diagnostic properties and are very shallow and shallow to a lithic contact. Pantano soils have calcic horizons. Anklam soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for livestock grazing. Vegetation is triangle bursage, paloverde, ocotillo, limberbush, ironwood, guajilla, janusia, range ratany, spidergrass, and saguaro.
DISTRIBUTION AND EXTENT: Southern Arizona. This series is moderately extensive. MLRA 40.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Pima County, Arizona; Soil survey of the Tohono O'odham Nation, AZ, Parts of Maricopa, Pima and Pinal Counties; 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: the zone from 0 to 2 inches (A horizon)
Argillic horizon: the zone from 2 to 16 inches (Bt1, Bt2 horizon)
Paralithic contact: the boundary at 16 inches (2Crtk horizon)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
Revised for the correlation of AZ661, 2/2009, WWJ
ADDITIONAL DATA:
Lab data: BIA-NREL, FY-87, sample numbers 129-131.