LOCATION MONTCAN AZEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, thermic Torrifluventic Haplustolls
TYPICAL PEDON: Montcan sandy loam - recreation and wildlife habitat. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; moderate thick platy structure; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; few very fine and fine irregular pores; 10 percent gravel; noneffervescent; slightly acid (pH 6.4); abrupt smooth boundary. (0 to 1 inch thick)
A2--1 to 4 inches; brown (10YR 5/3) sandy loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few fine and pockets of many very fine roots; few very fine and fine irregular and tubular pores; 7 percent gravel; noneffervescent; slightly acid (pH 6.2); clear smooth boundary. (2 to 5 inches thick)
Bw--4 to 13 inches; brown (7.5YR 4/3) gravelly sandy loam, very dark brown (7.5YR 2.5/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few very fine, fine and medium roots; few very fine and fine irregular and tubular pores; 15 percent gravel, 5 percent cobble; noneffervescent; neutral (pH 7.0); clear wavy boundary. (8 to 12 inches thick)
2C1--13 to 24 inches; brown (7.5YR 5/3) very cobbly loamy sand, very dark brown (7.5YR 2.5/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, few fine and medium roots; common very fine and fine irregular pores; 20 percent gravel, 15 percent cobble, 5 percent stone; noneffervescent; neutral (pH 7.0); clear wavy boundary.
2C2--24 to 31 inches; brown (7.5YR 5/3) extremely cobbly sandy loam, very dark brown (7.5YR 2.5/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; isolated pockets of very fine, fine and medium roots; few fine, common medium and coarse irregular pores; 15 percent gravel, 35 percent cobble, 20 percent stone; noneffervescent; slightly alkaline (pH 7.4); clear wavy boundary.
2C3--31 to 60 inches; light brown (7.5YR 6/3) extremely stony coarse sand, dark brown (7.5YR 3/3) moist; single grain; loose, nonsticky and nonplastic; isolated pockets of very fine, fine, and medium roots; common very fine, fine and few medium irregular pores; 15 percent gravel, 30 percent cobble, 30 percent stone; noneffervescent; slightly alkaline (pH 7.6). (Combined thickness of the C horizons is 45 to 50 inches)
TYPE LOCATION: Coronado National Memorial; located at a latitude of 31 degrees, 20 minutes, 2 seconds North and longitude of 110 degrees, 13 minutes, 39 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: averages 50 to 60 percent, but can range to 80 percent in any one horizon
Clay content: averages less than 8 percent, but can range to 12 percent in any one horizon
A horizon
Hue: 7.5YR, 10YR
Value: 4 or 5 dry, 2 through 3 moist
Chroma: 2 or 3, dry or moist
Texture: sandy loam, fine sandy loam
Bw horizon
Value: 4 or 5 dry, 2.5 or 3 moist
Chroma: 2 or 3, dry or moist
Texture: sandy loam, fine sandy loam
Reaction: slightly acid, neutral
Rock fragments: 5 to 25 percent
C horizon
Value: 4 through 7 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture: stratified, coarse sand to sandy loam
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Montcan soils are on stream terraces and floodplains at elevations of 4850 to 5200 feet. Slopes range from 3 to 5 percent. These soils formed in stream alluvium from mixed sources. The mean annual precipitation is 16 to 18 inches and occurs as thunderstorms during July 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 Amuzet soil. Amuzet soils do not have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Excessively drained; slow runoff; very rapid permeability. Subject to rare flooding.
USE AND VEGETATION: Used for wildlife habitat. Vegetation includes Lehmans lovegrass, beggartick threeawn, wait-a-bit mimosa, cane beardgrass, mesquite and Mexican blue oak.
DISTRIBUTION AND EXTENT: Southern Arizona. Montcan soils are of limited extent. MLRA is 41. The name is from nearby Montezuma Canyon.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cochise County, Arizona; Soil survey of Coronado National Memorial; 1996.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 13 inches (A1, A2, Bw horizons)
Fluvial feature - Irregular decrease in organic carbon in the zone from 13 to 60 inches (2C1, 2C2, 2C3 horizons)