LOCATION RUINS AZEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Vertic Paleargids
TYPICAL PEDON: Ruins fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.) 5 to 20 percent of the surface is covered with gravel and/or cobble
A--0 to 5 inches; reddish brown (5YR 5/4) fine sandy loam, dark reddish brown (5YR 3/4) moist; moderate thin platy structure; soft, friable, nonsticky and nonplastic; many very fine and fine roots; common fine irregular pores; noneffervescent; slightly acid (pH 6.2); abrupt wavy boundary. (1 to 6 inches thick)
Bt1--5 to 9 inches; dark reddish brown (2.5YR 3/4) gravelly clay loam, reddish brown (2.5YR 4/3) moist; moderate medium subangular blocky structure; soft, friable, moderately sticky and moderately plastic; common fine and medium roots; common fine tubular pores; common distinct clay films on ped faces and on rock fragments; 20 percent gravel; noneffervescent; slightly acid (pH 6.4); clear wavy boundary.
Bt2--9 to 20 inches; dark reddish brown (2.5YR 3/4) clay, dark reddish brown (2.5YR 3/4) moist; strong medium angular blocky structure parting to strong fine angular blocky; hard, firm, very sticky and very plastic; many medium and few fine and very fine roots matted between ped faces; few fine tubular pores; many distinct clay films on ped faces; noneffervescent; neutral (pH 6.8); abrupt wavy boundary.
Bt3--20 to 28 inches; dark reddish brown (2.5YR 3/4) clay, dark reddish brown (2.5YR 3/4) moist; strong very coarse and coarse wedges; hard, firm, very sticky and very plastic; many medium roots with few fine and very roots matted between ped faces; few fine tubular pores; many distinct clay films on ped faces; many distinct pressure faces; noneffervescent; neutral (pH 6.8); abrupt wavy boundary.
Bt4--28 to 60 inches; dark reddish brown (2.5YR 3/3) very cobbly clay loam, dark reddish brown (2.5YR 3/4) moist; moderate fine subangular blocky structure; hard, friable, very sticky and very plastic; few fine and very fine roots; few fine tubular pores; many distinct clay films on ped faces and rock fragments; 30 percent cobble and 20 percent gravel; noneffervescent; neutral (pH 7.2). (Combined thickness of the Bt horizons is 40 to 60 inches)
TYPE LOCATION: Cochise County, Arizona; located at a latitude of 31 degrees, 32 minutes, 42 seconds North and longitude of 110 degrees, 00 minutes, 24 seconds West; 1,000 feet north and 1,000 feet west from southeast corner of section 4, T. 22 S., R. 23 E.
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 69 degrees F.
Rock fragments: averages less than 35 percent in the control section
Reaction: slightly acid to slightly alkaline
Clay content: greater than 35 percent
A horizon
Hue: 7.5YR, 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 through 6, dry or moist
Texture: sandy loam, fine sandy loam, loamy fine sand
Bt horizon
Hue: 2.5YR, 5YR
Value: 3 through 5 dry, 3 or 4 moist
Chroma: 3 through 6, dry or moist
Texture: clay loam, clay
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Ruins soils are on high fan terraces at elevations of 4,400 to 5,000 feet. Slopes range from 1 to 5 percent. These soils formed in fan alluvium from quartz, sandstone and arkose. The mean annual precipitation is 12 to 16 inches and occurs as thunderstorms during July to September and as gentle rains during December and January. The mean annual air temperature is 60 to 67 degrees F. The frost-free period is 180 to 230 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Naco, Nolam, Libby, Buntline and Keysto soils. Nolam and Keysto soils are loamy-skeletal. Buntline soils have a hardpan. Naco soils are clayey-skeletal. Libby soils contain petronodes.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; very slow permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation includes mesquite, vine mesquite, sideoats grama, shrubby buckwheat, range ratany, curly mesquite, and false mesquite.
DISTRIBUTION AND EXTENT: Southern Arizona. Ruins soils are of moderate extent. MLRA is 41.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cochise County, Arizona; Soil survey of Cochise County, AZ, Douglas-Tombstone Part; 1996.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 5 inches (A horizon)
Argillic horizon - The zone from 5 to 60 inches (Bt1, Bt2, Bt3, Bt4 horizons)
Pale feature - abrupt textural change at 5 inches
Soil Taxonomy Second Edition, 1999