LOCATION ARP AZEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Ustic Haplargids
TYPICAL PEDON: Arp gravelly clay loam, brushland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; brown (7.5YR 4/4) gravelly clay loam, dark reddish brown (5YR 3/4) moist; moderate fine granular structure; slightly hard, friable, sticky and plastic; few fine roots; many fine interstitial pores; noneffervescent; slightly acid (pH 6.5); abrupt smooth boundary. (1 to 2 inches thick)
Bt1--2 to 5 inches; reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; moderate fine and medium subangular blocky structure; hard, friable, sticky and plastic; common fine, medium and coarse roots; common fine tubular and common fine interstitial pores; common thin clay films on ped faces; noneffervescent; neutral (pH 7.0); clear smooth boundary. (2 to 4 inches thick)
Bt2--5 to 11 inches; reddish brown (5YR 5/4) clay, dark reddish brown (5YR 3/4) moist; moderate fine and medium subangular and angular blocky structure; hard, friable, sticky and plastic; common fine, medium and coarse roots; few fine tubular and common fine interstitial pores; common thin clay films on ped faces; noneffervescent; neutral (pH 7.0); clear smooth boundary. (4 to 7 inches thick)
Bt3--11 to 18 inches; strong brown (7.5YR 5/6) clay, brown (7.5YR 4/4) moist; massive breaking to moderate medium subangular blocky structure; hard, friable, sticky and plastic; few fine roots; few fine tubular and common fine interstitial pores; common thin clay films on ped faces; noneffervescent; neutral (pH 7.0); clear irregular boundary. (5 to 9 inches thick)
2Cr--18 to 34 inches; weathered schist.
3R--34 inches; hard schist.
TYPE LOCATION: Yavapai County, Arizona. 6/10 mile south and 1/2 mile west of NE corner of sec. 8, T.12N., R.1E. About 3 miles NW of Mayer on State Highway 69 and 1 mile west along road to old mine in National Forest.
RANGE IN CHARACTERISTICS:
Depth to the consolidated schist bedrock: 20 to 40 inches
Reaction: medium acid (pH 6.0) to neutral (pH 7.0).
Mean annual soil temperature: about 56 degrees F
Soil moisture: These soils are usually dry especially during the months of April through June and October through November. These soils have more than 1 percent organic matter. Ustic aridic moisture regime.
A horizon
Hue: 5YR to 10YR
Value: 4 and 5 dry and 2 and 3 moist
Chroma: 2 to 4
Texture: gravelly loam, cobbly loam, clay loam, gravelly clay loam, cobbly clay loam and very stony clay loam.
Bt horizons
Hues: 2.5YR to 7.5YR, but are dominantly 5YR
Values: 2 to 5 dry, and 3 and 4 moist
Chroma: 4 to 6
Texture: clay loam and clay
Clay content: more than 35 percent but less than 60 percent clay.
R horizon
Usually schist bedrock, but includes local areas of quartzite and phyllite bedrock.
COMPETING SERIES: These are the Agua Fria (NM), Bacid (CO), Bessemer (WY), Manzanola (CO), Mughouse (CO), Rencalson (WY), Renohill (WY), Ulm (WY), Winklo (NV) and Wyarno series. Agua Fria, Bacid, Bessemer and Wyarno soils are very deep. Bessemer soils Manzanola, Renohill, and Ulm soils have hue yellower than 7.5YR in the B2t horizon. Mughouse, Rencalson and Renohill soils have sedimentary bedrock at depths of 20 to 40 inches. Winklo soils are moderately deep to tuff, slightly or moderately alkaline and have accumulations of carbonates (Btk horizons).
GEOGRAPHIC SETTING: Arp soils are on undulating to steep phyllite and schist hills. Slopes are dominantly 2 to 60 percent. These soils are formed in slope alluvium over schist and phyllite bedrock. Arp soils are at elevations of 4,000 to 5,500 feet in a semiarid continental climate with an average annual precipitation of 12 to 16 inches. About one-half of this occurs in July and August as rain and about one-third in December, January and February as rain with some snow. The mean annual temperature ranges from 52 degrees to 57 degrees F. Frost-free season is about 140 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Balon, Barkerville, Dandrea, Gaddes, Lynx, Moano, and Showlow soils. Balon soils are deep. Barkerville soils lack an argillic horizon. Dandrea soils have hues of 10YR and 7.5YR. Gaddes soils are moderately fine textured and have mixed mineralogy. Lynx soils are deep and lack an argillic horizon. Moano soils are shallow and lack an argillic horizon. Showlow soils are deep and have a horizon of lime accumulation.
DRAINAGE AND PERMEABILITY: Well-drained with medium surface runoff. Permeability is moderately slow to slow.
USE AND VEGETATION: Used only for rangeland. Native vegetation consists of oak brush, squawbush, manzanita and mountain mahogany with an understory of grama grasses, three-awns, snakeweed, and annuals.
DISTRIBUTION AND EXTENT: Central and southern Yavapai County, Arizona. These soils are moderate in extent. MLRA 38.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Western Yavapai County Area, Yavapai County, Arizona, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon The zone 0 to 2 inches. (A horizon)
Argillic horizon The zone from 2 to 18 inches. (Bt horizons)
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.