LOCATION SIPHONCAN AZInactive Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Aridic Lithic Haplustolls
TYPICAL PEDON: Siphoncan very gravelly coarse sandy loam - rangeland, wildlife habitat and recreation. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1 inch; brown (10YR 5/3) very gravelly coarse sandy loam, brown (10YR 4/3) moist; moderate fine subangular blocky and weak fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine irregular pores; 50 percent gravel; noneffervescent; neutral (pH 6.6); abrupt wavy boundary.
A2--1 to 7 inches; brown (10YR 4/3) very gravelly sandy loam, very dark brown (10YR 2/2) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few medium roots; common very fine and fine irregular and tubular pores; few faint clay films bridging mineral grains; 40 percent gravel, 10 percent cobble, 5 percent stone; noneffervescent; slightly acid (pH 6.2); clear wavy boundary. (Combined thickness of the A horizons is 2 to 8 inches)
Bw--7 to 12 inches; yellowish brown (10YR 5/4) and brown (10YR 4/3) very gravelly sandy clay loam, dark yellowish brown (10YR 3/4) and very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine irregular and few very fine tubular pores; few faint clay films bridging mineral grains; 50 percent gravel; noneffervescent; neutral (pH 6.8); clear irregular boundary. (3 to 6 inches thick)
C--12 to 18 inches; light yellowish brown (10YR 6/4) very gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; massive; hard, friable, moderately sticky and slightly plastic; few very fine and fine roots; common very fine and fine irregular and few very fine and fine tubular pores; very few faint clay films bridging mineral grains; 55 percent gravel; noneffervescent; neutral (pH 6.6); clear irregular boundary. (0 to 6 inches thick)
R--18 inches; hard, granite bedrock.
TYPE LOCATION: Fort Bowie National Historic Site; located at a latitude of 32 degrees, 9 minutes, 7 seconds North and longitude of 109 degrees, 28 minutes, 32 seconds West.
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. Aridic ustic soil moisture regime.
Soil Temperature: 59 to 64 degrees F.
Rock fragments: more than 35 percent
Clay content: 18 to 27 percent
Reaction: moderately acid to neutral
Organic matter: 1 to 3 percent
Depth to bedrock: 8 to 20 inches
A horizon
Hue: 10YR, 7.5YR
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 1 through 3, dry or moist
Bw horizon
Hue: 10YR, 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 through 4, dry or moist
C horizon
Hue: 10YR, 7.5YR
Value: 5 or 6 dry, 4 or 5 dry
Chroma: 3 through 5, dry or moist
The C horizon may be absent in some pedons
COMPETING SERIES: These are Brewster (TX), Budlamp (AZ), Canguya (AZ) and Yarbam (AZ) series. Brewster soils formed in colluvium from rhyolite, trachyte, and basalt and are moist in the soil moisture control section during May and June. Budlamp and Yarbam soils contain less than 18 percent clay. Yarbam soils formed from calcareous parent material and have a calcium carbonate equivalent of 20 to 40 percent.
GEOGRAPHIC SETTING: Siphoncan soils are on hills and mountains at elevations of 4600 to 5300 feet. Slopes range from 10 to 40 percent. These soils formed in residuum and colluvium from granite. The mean annual precipitation is 16 to 20 inches and occurs as thunderstorms during duly to September and as gentle rains during December to February. The mean annual air temperature is 57 to 62 degrees F. The frost-free period is 180 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the competing Budlamp soil.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Used for livestock grazing, recreation and wildlife habitat. Vegetation includes Emory oak, alligator juniper, mesquite, manzanita, beargrass, cholla, prickly pear, catclaw, agave, sotol, turpentine bush, beargrass, bullgrass, Lehmann lovegrass, black grama, sideoats grama, hairy grama, and Texas bluestem.
DISTRIBUTION AND EXTENT: Southern Arizona. Siphoncan soils are of limited extent. MLRA is 41. The name is from nearby Siphon Canyon.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cochise County, Arizona; Soil survey of Fort Bowie National Historic Site; 1996.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 7 inches (A1, A2 horizons)
Lithic contact - The boundary at 18 inches (R horizon)
Classification changed to Aridic Lithic subgroup in 2007.
Classified according to Keys to Soil Taxonomy Tenth Edition, 2006