LOCATION TAPCO AZ
Established Series
Rev. DRT/PDC
08/2012
TAPCO SERIES
The Tapco series consists of very shallow and shallow to a duripan, well drained soils that formed in mixed alluvium. Tapco soils are on fan remnants and have slopes of 0 to 15 percent. The mean annual precipitation is about 14 inches and the mean annual air temperature is about 62 degrees F.
TAXONOMIC CLASS: Clayey, smectitic, thermic, shallow Duric Petroargids
TYPICAL PEDON: Tapco very gravelly clay loam - rangeland. (Colors are for dry soil unless otherwise noted.) Subangular and rounded gravel covers about 80 percent of the surface.
A--0 to 3 inches; brown (7.5YR 4/4) very gravelly clay loam, dark brown (7.5YR 3/4) moist; moderate very fine granular structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots; common very fine and fine tubular pores; slightly effervescent; moderately alkaline (pH 7.9); clear smooth boundary. (l to 4 inches thick)
Bt--3 to 8 inches; brown (7.5YR 4/4) clay, dark brown (7.5YR 3/4) moist; moderate fine and medium subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; common very fine and fine roots; common very fine and medium tubular pores; many faint clay films on faces of peds; 10 percent gravel; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (4 to 8 inches thick)
Btk--8 to 18 inches; reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, firm, very sticky and very plastic; common very fine and few medium roots; few very fine tubular pores; many faint clay films on faces of peds; 10 percent gravel; few fine calcium carbonate threads and soft masses; strongly effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary. (3 to 8 inches thick)
2Bkqm--18 to 26 inches; pink (5YR 7/3), pinkish white (5YR 8/2) and white (5YR 8/1) indurated silica-lime cemented hardpan with thin laminar layer on the surface, reddish brown (5YR 5/4) and pink (7.5YR 8/4) moist; massive; extremely hard; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (6 to 15 inches thick)
2Bkkm--26 to 60 inches; pinkish white (7.5YR 8/2) calcium carbonate-cemented sand, gravel and cobble, light brown (7.5YR 6/4) moist; massive; hard; 85 percent gravel and cobble; violently effervescent; strongly alkaline (pH 8.6).
TYPE LOCATION: Yavapai County, Arizona; located about 2,200 feet north and 540 feet east of the SW corner of section 11, T. 15 N., R. 3 E.; Latitude 34 degrees 42 minutes 33.0 seconds N; Longitude 112 degrees 00 minutes 28.0 seconds W.
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. Ustic aridic soil moisture regime.
Soil Temperature: 62 to 65 degrees F.
Depth to duripan: 4 to 20 inches
Clay content: Averages 35 to 50 percent in the particle-size control section
Rock fragments: 5 to 30 percent gravel and cobble in the particle-size control section
Reaction: neutral to moderately alkaline
A horizon
Hue: 5YR, 7.5YR
Value: 3 through 6, dry or moist
Chroma: 2 through 4, dry or moist
Organic matter: less than 1 percent
Bt horizon
Hue: 2.5YR, 5YR, 7.5YR
Value: 3 through 6, dry or moist
Chroma: 3 through 6, dry or moist
Effervescence: noneffervescent to strongly
Calcium carbonate equivalent: 0 to 10 percent
Texture: clay, clay loam
Bkm horizon
Indurated silica-lime cemented duripan
Bk or Bkm horizons
Hue: 7.5YR, 10YR
Value: 5 through 8 dry, 4 through 7 moist
Chroma: 0 through 4, dry or moist
Effervescence: strongly to violently effervescent
Calcium carbonate equivalent: 20 to 50 percent
Texture: coarse sandy loam, sandy loam; variable calcium carbonate cementation in some pedons
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Tapco soils are on fan remnants and have slopes of 0 to 15 percent. They formed in gravelly fine-textured, mixed alluvium. Elevations are 2,900 to 5,000 feet. Mean annual precipitation is 12 to 16 inches. Mean annual air temperature is 60 degrees to 63 degrees F. Frost-free period is about 180 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Mingus soils. Mingus soils have a duripan at depths of 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow to very slow permeability.
USE AND VEGETATION: Used for livestock grazing and homesites. Vegetation is tobosa, mesquite, catclaw acacia, turpentinebush and filaree.
DISTRIBUTION AND EXTENT: Central Arizona. The soils are moderately extensive. MLRAs 38 & 41.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Graham County, Arizona; Soil survey of Gila-Duncan Area, Arizona, Parts of Graham and Greenlee Counties, Arizona, 1979.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 3 inches (A horizon)
Argillic horizon - The zone from 3 to 18 inches (Bt, Btk horizons)
Duripan - The zone from 18 to 26 inches (2Bkqm horizon)
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
The current type location is no longer accessible because it occurs in an area that has been heavily developed. It is recommended that the type location be moved to another suitable location nearby,
ADDITIONAL DATA: NSSL pedon ID: 80AZ025006
National Cooperative Soil Survey
U.S.A.