LOCATION CORAZONES TX

Established Series
Rev. RAC/JLR/ACT
10/2012

CORAZONES SERIES

The Corazones series consists of very deep, well drained, moderately rapidly permeable soils that formed in gravelly alluvium. These soils are on undulating to strongly rolling coalescent fan piedmonts and fan remnants. Slopes range from 1 to 50 percent.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, hyperthermic Ustic Haplocalcids

TYPICAL PEDON: Corazones very gravelly sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 2 inches; pale brown (10YR 6/3) very gravelly sandy loam; brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; 40 percent igneous gravel; 5 percent limestone gravel; strongly effervescent; moderately alkaline; abrupt smooth boundary. (1 to 6 inches thick)

Bw--2 to 8 inches; light yellowish brown (10YR 6/4) very gravelly sandy loam; yellowish brown (10YR 5/4) moist; weak medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; 45 percent igneous gravel; 5 percent igneous cobbles; strongly effervescent; moderately alkaline; clear wavy boundary. (3 to 19 inches thick)

Bk1--8 to 16 inches; light yellowish brown (10YR 6/4) very gravelly sandy loam; yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many continuous calcium carbonate coatings on rock fragments; 50 percent igneous gravel; 5 percent igneous cobbles; violently effervescent; moderately alkaline; clear wavy boundary.

Bk2--16 to 26 inches; light yellowish brown (10YR 6/4) extremely gravelly sandy loam; yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots; many continuous calcium carbonate coatings on rock fragments; 40 percent igneous gravel; 5 percent igneous cobbles; 10 percent limestone gravel; 10 percent limestone cobbles; violently effervescent; moderately alkaline; gradual wavy boundary.

Bk3--26 to 36 inches; yellowish brown (10YR 5/4) extremely gravelly coarse sandy loam; dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; common discontinuous calcium carbonate coatings on rock fragments; 50 percent igneous gravel; 5 percent igneous cobbles; 20 percent limestone gravel; 2 percent limestone cobbles; violently effervescent; moderately alkaline; gradual wavy boundary.

Bk4--36 to 48 inches; light yellowish brown (10YR 6/4) extremely gravelly coarse sandy loam; yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; common patchy calcium carbonate coatings on rock fragments; 65 percent igneous gravel; 5 percent igneous cobbles; 10 percent limestone gravel; 2 percent limestone cobbles; violently effervescent; moderately alkaline; gradual wavy boundary.

Bk5--48 to 80 inches; light yellowish brown (10YR 6/4) extremely gravelly loamy coarse sand; yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few patchy calcium carbonate coatings on rock fragments; few fine and medium cylindrical gypsum crystals; 60 percent igneous gravel; 10 percent igneous cobbles; 5 percent limestone cobbles; strongly effervescent; slightly alkaline. (Combined thickness of Bk horizons range from 50 to 90 inches.)

TYPE LOCATION: Brewster County, Texas; From the junction of Texas Highway 118 and Texas Highway 170 at Study Butte; 1.5 miles north on Texas Highway 118 to gate 2 of Terlingua Ranch; 0.9 miles east and south on ranch road; 100 feet south of road at 90 degree bend to east in road. Latitude: 29 degrees, 21 minutes, 23 seconds North; Longitude: 103 degrees, 30 minutes, 56 seconds West.

RANGE IN CHARACTERISTICS:

Solum thickness: greater than 80 inches

Depth to a calcic horizon: 4 to 25 inches

Desert pavement of igneous gravel covers from 75 to 95 percent of the surface

Total clay content: 7 to 18 percent

Rock fragments: 35 to 80 percent by volume

Soil moisture: Ustic aridic soil moisture regime. Receives precipitation in all months. Driest period is November through April with peak rainfall occurring during May through October.

A horizon
Hue: 7.5YR, 10YR
Value: 4 to 7, dry or moist
Chroma: 2 to 4, dry or moist
Texture: sandy loam, loam, fine sandy loam, sandy clay loam
Rock fragments: 15 to 75 percent and are 1 to 3 inches in diameter.
Calcium carbonate equivalent: 5 to 15 percent

Bw horizon
Hue: 7.5YR, 10YR
Value: 5 to 7, dry or moist
Chroma: 2 to 4, dry or moist
Texture: sandy loam, loam
Rock fragments: 15 to 75 percent and are mostly 1 to 3 inches in diameter
Calcium carbonate content: 5 to 15 percent

Bk horizon
Hue: 7.5YR, 10YR
Value: 4 to 8, dry or moist
Chroma: 2 to 4, dry or moist
Texture: loamy coarse sand, loamy sand, coarse sandy loam, sandy loam, loam, fine sandy loam
Rock fragments: 35 to 80 percent
Calcium carbonate content: 15 to 30 percent
Reaction: slightly alkaline to moderately alkaline

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Corazones soils are on fan piedmonts, pediments, and fan remnants. They formed in Pleistocene calcareous gravelly deposits from mixed sources. Mean annual precipitation ranges from 10 to 13 inches. Most precipitation falls during the late summer months. Mean annual air temperature ranges from 68 to 72 degrees F. Frost-free days range from 240 to 280 days, and elevation ranges from 1,800 to 4,000 feet. Slopes range from 1 to 50 percent.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lajitas, Tornillo and Solis soils. Lajitas soils are on igneous hills and mountains and are shallow to a lithic contact. Tornillo soils are on broad flats and do not have coarse fragments in the profile. Solis soils are shallow over sandstone and are on mountains in higher positions.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately rapid. Runoff is very low on 1 to 5 percent slopes, low on slopes of 5 to 20 percent, and medium on slopes greater than 20 percent.

USE AND VEGETATION: Used mainly for livestock grazing and wildlife habitat. The present vegetation is creosote bush, bush muhly and black grama.

DISTRIBUTION AND EXTENT: West Texas. MLRA 42. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Brewster County, Texas, 1996. The name is from a mountain near the type location.

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

Ochric epipedon - The zone from 0 to 2 inches (A horizon)

Calcic horizon - The zone from 8 to 48 inches (Bk1, Bk2, Bk3 and Bk4 horizons)

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Eleventh Edition, 2010.

The series was formerly included in the Nickel series which is now restricted to the Mohave Desert.

Moisture and temperature regimes revised for TX622, Brewster County, TX, Main Part, recorrelation, 2/7/08, CEM

Revised for the correlation of Big Bend National Park, TX, Oct. 2010, CEM

Revised for the correlation of Hudspeth County, Texas (Main Part) and Culberson County, Texas (Main Part); July, 2012, NMS

Revised for the correlation of Presidio County, Texas ; Oct, 2012, WWJ

ADDITIONAL DATA: Lincoln laboratory data is available on this pedon (S91TX-043-008).

National Cooperative Soil Survey
U.S.A.