LOCATION GYPROCKMESA             CO

Established Series
Rev. RLR/CRP/JCK
04/2019

GYPROCKMESA SERIES

The Gyprockmesa series consists of very deep, well drained soils that formed in alluvium. These soils are on stream terraces and alluvial fans. Slopes are from 0 to 12 percent. Mean annual precipitation is about 203 mm, and mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Gypsiargids

TYPICAL PEDON: Gyprockmesa clay loam, in an alfalfa field at an elevation of 1,457 meters. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 13 cm; pale brown (10YR 6/3) clay loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky parting to weak fine granular structure; hard, friable, slightly sticky and slightly plastic; common fine roots; common very fine and fine tubular pores; 10 percent gravel; strongly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (10 to 25 cm thick)

Btk1--13 to 25 cm; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; moderate medium prismatic parting to moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common fine roots inside and between peds; common very fine and fine tubular pores; few distinct clay films on faces of peds and few distinct carbonate coats on rock fragments; 10 percent gravel; strongly effervescent; slightly alkaline (pH 7.6); clear wavy boundary.

Btk2--25 to 38 cm; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; moderate medium prismatic parting to moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common fine roots inside and between peds; common very fine and fine tubular pores; few distinct clay films on faces of peds and common distinct carbonate coats on rock fragments; many fine and medium irregular calcium carbonate masses in the matrix; violently effervescent; 10 percent gravel; slightly alkaline (pH 7.6); clear wavy boundary.

Btk3--38 to 58 cm; brown (7.5YR 5/4) cobbly clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common fine roots inside and between peds; common very fine and fine tubular pores; few distinct clay bridges between grains and lining pores, few faint clay films on faces of peds, and common distinct carbonate coats on rock fragments; many fine and medium irregular calcium carbonate masses in the matrix; 15 percent gravel, 10 percent cobbles and 5 percent stones; violently effervescent, slightly alkaline (pH 7.6); clear wavy boundary. (combined thickness of Btk horizons is 42 to 90 cm)

BCky1--58 to 89 cm; brown (7.5YR 5/4) very cobbly clay loam, brown (7.5YR 5/4) moist; massive; hard, friable, moderately sticky and moderately plastic; common fine roots throughout; common very fine and fine tubular pores; common distinct carbonate coats on rock fragments; many fine and medium irregular carbonate masses and few fine and medium gypsum masses in the matrix; 30 percent gravel, 20 percent cobbles and 5 percent stones; violently effervescent; moderately alkaline (pH 7.9); clear wavy boundary. (0 to 40 cm thick)

BCky2--89 to 112 cm; pink (7.5YR 7/4) cobbly clay loam, light brown (7.5YR 6/4) moist; massive; hard, friable, moderately sticky and moderately plastic; common fine roots throughout; common very fine and fine tubular pores; common distinct carbonate coats on rock fragments; many fine and medium irregular carbonate masses and few fine and medium gypsum masses in the matrix; 10 percent gravel and 10 percent cobbles; violently effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 35 cm thick)

BCky3--112 to 200 cm; pink (7.5YR 7/4) stony loam, light brown (7.5YR 6/4) moist; massive; hard, friable, moderately sticky and moderately plastic; common fine roots throughout; common very fine and fine tubular pores; few fine calcium carbonate masses and many fine and medium gypsum masses in the matrix; 5 percent gravel, 5 percent cobbles and 10 percent stones; violently effervescent; slightly alkaline (pH 7.6).

TYPE LOCATION: Mesa County, Colorado; about 366 meters east and 686 meters south of the northwest corner of sec. 24 T. 1 S., R. 1 E. USGS Clifton, Colorado topographic quadrangle, NAD 27; UTM 21950 meters E, 26100 meters N, zone 12

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 11 to 14 degrees C
Particle-size control section (weighted average):
Clay content - 27 to 35 percent
Rock fragments - 0 to 35 percent; 0 to 25 percent gravel, 0 to 15 percent cobbles, 0 to 5 percent stones

Ap horizon
Hue: 7.5YR or 10YR
Value: 4, 5, or 6 dry; 3, 4 or 5 moist
Chroma: 2, 3 or 4
Texture: clay loam or loam
Clay content: 20 to 32 percent
Rock fragments: 0 to 35 percent; 0 to 25 percent gravel, 0 to 15 percent cobbles
Electrical conductivity: 2 to 4 mmhos/cm
Sodium adsorption ratio: 0 to 4
Reaction: pH 7.6 to 8.4

Btk horizons
Hue: 7.5YR or 10YR
Value: 5, 6, or 7 dry; 4, 5 or 6 moist
Chroma: 3, 4 or 5
Texture: clay loam, silty clay loam, or sandy clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 35 percent; 0 to 25 percent gravel, 0 to 15 percent cobbles, 0 to 5 percent stones
Calcium carbonate equivalent: 5 to 40 percent
Electrical conductivity: 2 to 4 mmhos/cm
Sodium adsorption ratio: 0 to 8
Reaction: pH 7.6 to 8.4

BCky horizons
Hue: 7.5YR or 10YR
Value: 5, 6, or 7 dry; 4, 5 or 6 moist
Chroma: 3, 4 or 5
Texture: clay loam, loam, sandy clay loam or sandy loam
Clay content: 15 to 35 percent
Rock fragments: 15 to 60 percent; 5 to 35 percent gravel, 5 to 25 percent cobbles, 0 to 15 percent stones
Calcium carbonate equivalent: 5 to 25 percent
Gypsum content: 1 to 40 percent
Electrical conductivity: 2 to 8 mmhos/cm
Sodium adsorption ratio: 0 to 8
Reaction: pH 7.4 to 8.4

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Landform - stream terraces and alluvial fans
Elevation - 1,372 to 1,768 meters
Slopes - 0 to 12 percent
Parent material - alluvium
Mean annual air temperature - 10 to 12.8 degrees C
Mean annual precipitation - 152 to 229 mm
Precipitation pattern - significant increases in spring, late summer and early fall
Frost-free period - 140 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mack, Gypimack, Fruita, and Fruitvale series. Mack soils do not have a gypsic horizon and Gypimack soils have a gypsic horizon above 100 cm. Fruita soils do not have a calcic horizon and Fruitvale soils have clayey substrata.

DRAINAGE AND PERMEABILITY: Well drained; moderately slow and moderate permeability.

USE AND VEGETATION: Gyprockmesa soils are used for irrigated cropland, fruit orchard production, and urban development. Native vegetation is Indian ricegrass, galleta, shadscale saltbush and fourwing saltbush.

DISTRIBUTION AND EXTENT: Gyprockmesa soils are of moderate extent in western Colorado. MLRA 34B.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Ridgway Area, Colorado, Parts of Delta, Gunnison, Montrose, and Ouray Counties, 2019.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon from - 0 to 13 cm (Ap horizon)
Argillic horizon from - 13 to 58 cm (Btk1, Btk2, and Btk3 horizons)
Calcic horizon from - 25 to 112 cm (Btk2, Btk3, BCky1 and BCky2 horizons)
Gypsic horizon from - 112 to 200 cm (BCky3 horizon)
Particle-size control section from - 13 to 58 cm (Btk1, Btk2, and Btk3 horizons)

Gypimack soils have a mesic temperature regime and an aridic moisture regime.

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National Cooperative Soil Survey
U.S.A.