LOCATION KELLYPOINT AZEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Argiustolls
TYPICAL PEDON: Kellypoint very cobbly silty clay loam - woodland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; dark brown (7.5YR 3/2) very cobbly silty clay loam; very dark brown (7.5YR 2.5/2) moist; strong very fine granular structure; soft, very friable, moderately sticky and moderately plastic; few very fine roots; many very fine and fine irregular pores; noneffervescent; 20 percent gravel, 25 percent cobble, 10 percent stone; neutral (pH 6.8); abrupt smooth boundary. (1 to 3 inches thick.)
Bt--2 to 5 inches; dark brown (7.5YR 3/2) stony silty clay loam; very dark brown (7.5YR 2.5/3) moist; strong medium subangular blocky structure; hard, friable, very sticky and very plastic; common very fine through coarse roots; common very fine and fine and few medium and coarse tubular pores; few faint clay films on faces of peds; noneffervescent; 5 percent gravel, 5 percent cobble, 5 percent stone; neutral (pH 6.8); clear wavy boundary. (2 to 4 inches thick.)
Btss1--5 to 14 inches; dark brown (7.5YR 3/3) clay; very dark brown (7.5YR 2.5/3) moist; strong medium prismatic structure parting to strong medium angular blocky; very hard, firm, very sticky and very plastic; common fine through coarse roots, mainly exped; few fine tubular pores; many intersecting slickensides; many faint clay films on faces of peds; noneffervescent; 5 percent gravel, 5 percent cobble; neutral (pH 6.8); clear wavy boundary.
Btss2--14 to 28 inches; dark brown (7.5YR 3/2) cobbly clay; very dark brown (7.5YR 2.5/3) moist; strong coarse prismatic structure parting to strong medium and coarse angular blocky; very hard, firm, very sticky and very plastic; few fine and medium roots, mainly exped; few fine tubular pores; many intersecting slickensides; many faint clay films on faces of peds; noneffervescent; 5 percent gravel, 15 percent cobble; neutral (pH 6.8); abrupt irregular boundary. (Combined thickness of the Btss horizons is 20 to 25 inches.)
R--28 inches; fractured basalt bedrock.
TYPE LOCATION: Mohave County, Arizona; on Lake Mead National Recreation Area; 1000 feet north and 500 east of the southwest corner of section 33, T. 30 N., R. 11 W.; 35 degrees, 57 minutes, 15 seconds north latitude and 113 degrees 28 minutes, 19 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Is dry in some part for 90 or more days cumulative and is moist in some part for 45 consecutive days during June through October and more than half the time that the soil temperature is above 41 degrees F. The soil is driest during May and June. Aridic ustic soil moisture regime.
Soil Temperature: 50 to 56 degrees F.
Rock fragments: Averages 10 to 20 percent in the particle-size
control section. Ranges up to 65 percent in the surface layer.
Depth to bedrock: 24 to 32 inches
Depth to argillic horizon: 1 to 3 inches
A horizon
Hue: 7.5YR, 10YR
Value: 3 or 4 dry, 2, 2.5 or 3 moist
Chroma: 2, 2.5 or 3, dry or moist
Bt horizon
Value: 3 or 4 dry, 2.5 or 3 moist
Chroma: 2 or 3, dry or moist
Texture: silty clay loam, clay
Clay content: 35 to 45 percent
Btss horizons
Hue: 5YR, 7.5YR
Value: 2 to 4 dry, 2.5 or 3 moist
Chroma: 2 or 3, dry or moist
Clay content: 50 to 60 percent
COMPETING SERIES: These are the Kirley (SD), Oko (SD), Okreek (SD), Peno (SD) and Witten (SD) series. All these soils are in LRRs that are more moist in May and June. Kirley, Oko, Peno and Witten soils are more than 60 inches deep to bedrock. Okreek soils are 30 to 40 inches deep to weathered shale bedrock. In addition, these soils have accumulations of secondary calcium carbonate.
GEOGRAPHIC SETTING: Kellypoint soils are on plateaus and mesas at elevations of 5800 to 6600 feet. They formed in residuum from basalt. Slopes range from 2 to 15 percent. The mean annual precipitation is 13 to 17 inches. The mean annual air temperature is about 48 to 54 degrees F. The frost-free period is 135 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Luzena and Rockyroad series. Luzena and Rockyroad soils are less than 20 inches deep to basalt bedrock.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; very slow permeability.
USE AND VEGETATION: Kellypoint soils are used for recreation and grazeable woodland. Present vegetation is pinyon pine, Utah juniper, cliffrose, Wyoming big sagebrush, sulfer buckwheat, muttongrass, ceanothis, turbinella oak, bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Northwestern Arizona; MLRA is 35. Kellypoint series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Mohave County, Arizona, soil survey of Lake Mead National Recreation Area, 2001.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the 0 to 28 inches (A, Bt, Btss1, and Btss2 horizons).
Argillic horizon - The zone from 2 to 28 inches (Bt, Btss1, and Btss2 horizons).
Vertic feature - Presence of intersecting slickensides (Btss1, Btss2 horizons).
Lithic contact - The boundary at 28 inches (R horizon).