LOCATION MOMOLI AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, hyperthermic Typic Haplocambids
TYPICAL PEDON: Momoli very gravelly fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.) About 70 percent of the surface is covered with gravel - thin coat of desert varnish on gravel.
A--0 to 2 inches; light brown (7.5YR 6/4) very gravelly fine sandy loam, brown (7.5YR 4/4) moist; weak medium platy structure; slightly hard, very friable; few very fine roots; common very fine vesicular pores; 50 percent gravel; slightly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (1 to 3 inches thick)
Bk1--2 to 26 inches; light brown (7.5YR 6/4) very gravelly sandy loam, brown (7.5YR 4/4) moist; massive; loose; many very fine roots; many very fine irregular pores; few fine soft masses of calcium carbonate; 50 percent partially calcium carbonate coated gravel in lower part; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (20 to 30 inches thick)
Bk2--26 to 34 inches; brown (7.5YR 5/4) extremely gravelly sandy loam, brown (7.5YR 4/4) moist; single grain; loose; few very fine roots; many very fine irregular pores; few fine soft masses of calcium carbonate; 60 percent partially calcium carbonate coated gravel; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (6 to 17 inches thick)
Bk3--34 to 60 inches; light brown (7.5YR 6/4) very gravelly loamy sand, brown (7.5YR 5/4) moist; single grain; loose; many fine irregular pores; few fine masses of calcium carbonate; 45 percent partially calcium carbonate coated gravel; slightly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Pinal County, Arizona; 600 feet west and 800 feet north of the southeast corner of section 33, T. 6 S., R. 3 E. Latitude 32 degrees, 51 minutes, 9 seconds N., Longitude 112 degrees, 2 hours, 2 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-February. Driest during May and June. Typic aridic soil moisture regime.
Soil Temperature - 72 to 78 degrees F.
Rock fragments - 35 to 90 percent gravel in the control section; 15 to 85 percent in surface layer
Salinity- Averages 2 dS/m, but ranges up to 12
A horizon
Hue: 10YR, 7.5YR
Value: 4, 5 or 6 dry, 3, 4 or 5 moist
Chroma: 3 through 6, dry or moist
Organic matter: Less than 1 percent
Reaction: Neutral to moderately alkaline
Calcium carbonate: Noneffervescent to violently effervescent
B horizon
Hue: 10YR, 7.5YR
Value: 4 through 7 dry, 4 or 5 moist
Chroma: 3, 4, 5 or 6 dry, 4, 5 or 6 moist
Texture: Fine sandy loam, coarse sandy loam, sandy loam, loam (averages 5 to 18 percent clay). In some pedons the Bk horizon is loamy sand below 24 inches
Reaction: Neutral to moderately alkaline
Calcium carbonate: Noneffervescent to violently effervescent in the upper part, slightly to violently below a depth of 10 inches. Calcium carbonate is threadlike, disseminated, soft masses, or thin coatings on gravel. Calcium carbonate equivalent is less than 5 percent.
In some pedons a C horizon is below the Bw horizon.
A buried soil occurs at depths of 40 to 60 inches in some pedons.
COMPETING SERIES: These are the Chillon (T)(TX), Laposa (AZ), and Snapcan (AZ) series. Chillon soils receive more than 10 inches average annual precipitation, and do not receive significant amounts of moisture during the winter months, typical of the Chihuahuan Desert (MLRA 42). Laposa soils have bedrock at depths of 20 to 40 inches. Snapcan soils have fanglomerate at moderate depths and are moist in some part of the soil moisture control section for less than 20 days cumulative between July and September.
GEOGRAPHIC SETTING: Momoli soils are on stream and fan terraces and have slopes of 0 to 15 percent. They formed in fan alluvium from mixed sources. Elevation is 400 to 2500 feet. Mean annual precipitation is 2 to 10 inches occurring as summer thunderstorms and gentle winter rains. Mean annual air temperature is 69 to 75 degrees F. The frost-free period is about 240 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dateland, Denure, Gunsight and Gilman soils. Dateland, Denure and Gilman soils are coarse-loamy. Gunsight soils have a calcic horizon.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow to medium runoff; moderately rapid permeability.
USE AND VEGETATION: Used for livestock grazing following summer and winter rains and as a source of sand and gravel. Vegetation is creosotebush, triangle bursage, ironwood, bush muhly, threeawn, big galleta, and turkshead.
DISTRIBUTION AND EXTENT: Central and Southwestern Arizona. These soils are extensive. Total extent is about 212,000 acres. MLRA is 40.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Pinal County, Arizona, Western Part; 1983. Pronounced Moam-uh-lie.
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 26 inches (Bk1 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