Established Series


The Cabezon series consists of shallow, moderately slowly to slowly permeable soils that formed in eolian material over residuum derived from basalt. The Cabezon soils are on lava plateaus. Mean annual precipitation is about 14 inches and the mean annual temperature is about 49 degrees F.

TAXONOMIC CLASS: Clayey, smectitic, mesic Aridic Lithic Argiustolls

TYPICAL PEDON: Cabezon stony loam - rangeland. (Colors are for dry soils unless otherwise noted.)

A--0 to 4 inches; grayish brown (10YR 5/2) stony loam, very dark grayish brown (10YR 3/2) moist; moderate very fine granular structure; soft, very friable; many fine roots; 65 to 90 percent of the surface is covered with stones and cobbles; neutral; clear smooth boundary. (2 to 6 inches thick)

Bt--4 to 12 inches; brown (7.5YR 5/2) clay, dark brown (7.5YR 3/2) moist; strong medium subangular blocky structure; hard, firm, sticky; thin continuous clay films on faces of peds; many fine roots; cobbles and pebbles are about 20 percent by volume; neutral; abrupt smooth boundary. (6 to 14 inches thick)

R--12 inches; hard basalt bedrock with the upper 2 or 3 inches moderately fractured; reddish brown (5YR 5/3) soil material similar to the above horizon in some of the fractures; thin coatings of lime on some of the basalt.

TYPE LOCATION: Sandoval County, New Mexico; near east edge of Chivato Mesa, nearly due west of Cabezon peak in a nonsectionized area.


Soil Temperature: 49 to 55 degrees

Soil moisture: Intermittently moist in some part of the soil moisture control section during July-September and December-February. Driest during May and June. Aridic ustic moisture regime

Particle-size control section: 35 to 50 percent clay.

Depth to bedrock: 10 to 20 inches.

Rock fragments: 10 to 30 percent by volume.

Reaction: slightly acid or neutral

A horizon
Hue: 7.5YR or 10YR
Value: 5 or 4 dry and 3 or 2 moist
Chroma: 2 or 3
Texture: loam, clay loam or heavy sandy loam

Bt horizon
Hue: 2.5YR through 7.5YR
Value: 5 or 4 dry and 3 or 2 moist
Chroma: 2 or 3
Texture: clay or clay loam
Calcium carbonate has accumulated just above the bedrock in some pedons.

COMPETING SERIES: This is the Luzena (AZ) series. Luzena soils formed in alluvium, colluvium and residuum from andesite, rhyolite, tuff and volcanic breccia.

GEOGRAPHIC SETTING: Cabezon soils are on summits of lava plateaus and mesas. Elevation ranges from 6,400 to 8,100 feet. Slopes range mostly from 1 to 5 percent but range up to 15 percent. These soils formed in residuum from basalt that in places has been influenced by thin deposits of eolian material. The annual precipitation ranges from 13 to 18 inches and the annual temperature ranges from 47 to 53 degrees F. The frost free period is 100 to 135 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Apache soils and the Brolliar, Friana, McGaffey, Osoridge, Torreon, Springerville, and Thunderbird soils. All these soils lack bedrock within depth of 20 inches. Also, Friana and McGaffey soils have pachic and cumulic epipedons respectively and Osoridge soils lack mollic epipedons.

DRAINAGE AND PERMEABILITY: Well-drained; medium to very high runoff; moderately slow and slow permeability.

USE AND VEGETATION: Used for grazing. Principal plants are side-oats grama, blue grama, galleta, Arizona fescue and meticalf muhly with scattered ponderosa pine, pinyon and juniper.

DISTRIBUTION AND EXTENT: North-central and western New Mexico and north-central and eastern Arizona. MLRA 35, 36, 39 & 41; LRR-D. Use in MLRA 41 should be discontinued. This series is of moderate extent.


SERIES ESTABLISHED: Zuni Mountains Area, New Mexico, 1965.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - The zone from 0 to 12 inches (A, Bt horizons)

Argillic horizon - The zone from 4 to 12 inches (Bt horizon)

Lithic contact - The boundary at 12 inches (R horizon)

The classification was changed to an Aridic Lithic subgroup in 2006.

Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.

National Cooperative Soil Survey