LOCATION COCKSCOMB AZ
Established Series
Rev. BAL/PDC
08/2012
COCKSCOMB SERIES
The Cockscomb series consists of very deep, well drained soils that formed in basaltic alluvium overlying older mixed alluvium. Cockscomb soils are on mesas and hills and have slopes of 3 to 40 percent. Mean annual precipitation is about 18 inches and the mean annual air temperature is about 60 degrees F.
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Calcidic Haplustalfs
TYPICAL PEDON: Cockscomb very gravelly loam - woodland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1 inch; reddish brown (5YR 4/4) very gravelly sandy clay loam, reddish brown (5YR 4/4) moist; moderate fine angular blocky parting to moderate fine granular structure; slightly hard, very friable, sticky and plastic; common very fine and fine roots, common fine tubular pores; 50 percent gravel; slightly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 2 inches thick)
A2--1 to 3 inches; dark reddish brown (5YR 3/4) gravelly sandy clay loam, dark reddish brown (5YR 3/4) moist; weak thin platy parting to strong very fine granular structure; slightly hard, very friable, sticky and plastic; many very fine, common fine and few medium roots; common very fine and fine tubular pores; 20 percent gravel; strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 5 inches thick)
Btk1--3 to 13 inches; red (2.5YR 4/6) gravelly clay, red (2.5YR 4/6) moist; moderate coarse subangular blocky parting to strong medium angular blocky structure; hard, firm, very sticky and very plastic; many medium, common fine and few coarse roots; common fine tubular pores; 5 percent cobble and 15 percent gravel; common faint coats of calcium carbonate on undersides of rock fragments; many distinct clay films on faces of peds; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (9 to 12 inches thick)
Btk2--13 to 22 inches; red (2.5YR 4/6) gravelly clay, red (2.5YR 4/6) moist; strong fine and medium angular blocky structure; hard, firm, very sticky and very plastic; common medium and coarse roots; few fine tubular pores; 5 percent cobble and 20 percent gravel; common faint clay films on faces of peds; common strongly cemented calcium carbonate lenses; violently effervescent; moderately alkaline (pH 8.4); abrupt irregular boundary. (8 to 11 inches thick)
2Bk1--22 to 26 inches; pinkish white (7.5YR 8/2) gravelly sandy loam, reddish yellow (7.5YR 6/6) moist; massive; soft, very friable, slightly sticky and nonplastic; common medium roots; few fine tubular pores; 25 percent gravel; common, discontinuous, strongly calcium carbonate cemented lenses; violently effervescent, 20 percent calcium carbonate equivalent; moderately alkaline (pH 8.4); gradual wavy boundary. (3 to 5 inches thick)
2Bk2--26 to 60 inches; variegated pinkish white (7.5YR 8/2) and reddish yellow (7.5YR 8/6) very gravelly sandy loam, light brown (7.5YR 6/4) and reddish yellow (7.5YR 6/6) moist; massive and single grain; hard and loose, firm and loose; nonsticky and nonplastic; few fine and medium roots; few very fine irregular pores; 5 percent cobble, 40 percent gravel as mostly saprolitic sandstone and basalt; many thin weakly calcium carbonate cemented lamina between sandy loam layers; violently effervescent, 20 percent calcium carbonate equivalent; moderately alkaline (pH 8.4).
TYPE LOCATION: Yavapai County, Arizona; located about 1,290 feet south and 1,820 feet east of the NW corner of section 16, T. 17 N., R. 5 E. ; 34 degrees, 51 minutes, 28.7 seconds north latitude, and 111 degrees, 50 minutes, 31.1 seconds west longitude
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during July-August and December-January. Driest during May and June. Aridic ustic soil moisture regime.
Soil Temperature: 59 to 62 degrees F.
Clay content: averages 35 to 45 percent in the particle size control section
Rock fragments: averages 15 to 35 percent in the particle size control section, mostly gravel
Depth to calcic horizon: 17 to 30 inches
A horizons
Hue: 2.5YR, 5YR, 7.5YR
Value: 3 through 5, dry or moist
Chroma: 4 or 6, dry or moist
Calcium carbonate equivalent: 0 to 1 percent
Organic matter content: 1.0 to 2.0 percent
Btk horizons
Hue: 2.5YR, 5YR
Value: 3 through 5, dry or moist
Chroma: 4 or 6, dry or moist
Calcium carbonate equivalent: 2 to 5 percent
Organic matter content: 0.5 to 1.0 percent
Texture: Clay, clay loam
2Bk1 horizon
Hue: 5YR, 7.5YR
Value: 7 or 8 dry, 6 or 7 moist
Chroma: 2 through 4, dry or moist
Calcium carbonate equivalent: 15 to 25 percent
Organic matter content: Less than 0.5 percent
Texture: Sandy loam, sandy clay loam
Rock fragments: 20 to 45 percent, mostly gravel and cobble,
small amounts of silica may be present in some pedons.
2Bk2 horizon
The 2C horizon is highly variable in rock fragment content and color. Hardness may vary from very soft saprolitic material to discontinuous indurated lenses cemented by calcium carbonate.
Clay content: 2 to 10 percent
Calcium carbonate equivalent: 15 to 25 percent
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Cockscomb soils are on mesas and hills at elevations of 4,200 to 4,800 feet. Slopes range from 3 to 40 percent. These soils formed in basaltic alluvium overlying older mixed alluvium. The mean annual precipitation is 16 to 20 inches. The mean annual air temperature is 57 to 60 degrees F. The frost-free period is 180 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Turist and
Sedona soils. Sedona soils are shallow to paralithic contact and the Turist soils are very shallow to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; very slow permeability.
USE AND VEGETATION: Used for grazeable woodland, wildlife habitat and urban land. Present vegetation includes one seed juniper, canotia, prickly pear, wait-a-minute acacia, threeawn, beargrass and pinyon pine.
DISTRIBUTION AND EXTENT: Central Arizona. Cockscomb soils are of very limited extent. MLRA is 38. The name is derived from Cockscomb Rock near Sedona.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Yavapai County, Arizona; Soil survey of Black Hills-Sedona Area, Arizona, Parts of Coconino and Yavapai Counties; 1996.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 3 inches (A1, A2 horizons)
Argillic horizon - The zone from 3 to 22 inches (Btk1, Btk2 horizons)
Calcic horizon - the zone from 22 to 60 inches (2Bk1, 2Bk2 horizons)
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Eleventh Edition, 2010
Revised for the correlation of Black Hills-Sedona, AZ, August 2012, CEM
National Cooperative Soil Survey
U.S.A.