LOCATION MORGAMINE AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Pachic Haplustolls
TYPICAL PEDON: Morgamine very gravelly coarse sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1 inch; brown (7.5YR 4/2) very gravelly coarse sandy loam, black (7.5YR 2.5/1) moist; weak thin platy structure parting to strong very fine granular; soft, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and few fine irregular pores; 50 percent gravel, 2 percent cobble; noneffervescent; slightly acid (pH 6.4); abrupt smooth boundary.
A2--1 to 20 inches; dark brown (7.5YR 3/2) very gravelly sandy loam, black (7.5YR 2.5/1) moist; weak very fine subangular blocky structure parting to strong very fine granular; soft, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; few very fine and common fine irregular pores; 45 percent gravel, 5 percent cobble; noneffervescent; slightly acid (pH 6.2); clear wavy boundary. (Combined thickness of the A horizons is 16 to 21 inches)
Bw--20 to 27 inches; brown (7.5YR 4/2) very gravelly sandy clay loam, dark brown (7.5YR 3/2) moist; moderate very fine subangular blocky structure parting to moderate very fine granular; soft, very friable, moderately sticky and moderately plastic, common very fine, fine, medium and coarse roots; common fine and medium irregular pores; 50 percent gravel, 2 percent cobble; noneffervescent, slightly acid (pH 6.2); abrupt irregular boundary. (6 to 8 inches thick)
R--27 inches, dacite tuff.
TYPE LOCATION: Cochise County, Arizona; located at a latitude of 31 degrees, 21 minutes, 55 seconds North and longitude of 110 degrees, 17 minutes, 5 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: 52 to 58 degrees F.
Rock Fragments: averages 45 to 60 percent, dominated by gravel
Clay content: 20 to 27 percent
Organic Matter: 2 to 5 percent in the surface layer
Depth to unweathered bedrock: 20 to 30 inches
A horizons
Value: 3 or 4 dry, 2.5 or 3 moist
Chroma: 2 or 3 dry, 1 or 2 moist
Reaction: moderately acid or slightly acid
Bw horizon
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Reaction: moderately acid or slightly acid
COMPETING SERIES: This is the Quapaw (NM) series. Quapaw soils are very deep.
GEOGRAPHIC SETTING: Morgamine soils are on mountain side slopes at elevations of 6700 to 7800 feet. Slopes range from 55 to 70 percent. These soils formed in residuum and colluvium from dacite tuff. The mean annual precipitation is 23 to 25 inches and occurs as thunderstorms during July to September and as gentle rains during December and January. The mean annual air temperature is 50 to 56 degrees F. The frost free period is 140 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: Yaquican is the only associated soil and has a lithic contact within 20 inches of the surface.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability
USE AND VEGETATION: Morgamine soils are used for wildlife habitat. Vegetation includes Arizona white oak, Emory oak, pinyon pine, prickly pear, sideoats grama, plains lovegrass and bull grass.
DISTRIBUTION AND EXTENT: Southern Arizona. Morgamine soils are of limited extent. MLRA is 41. Name derived from Morgan Mine nearby.
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 27 inches (A1, A2, Bw horizons)