LOCATION GYPIMACK                CO

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

GYPIMACK SERIES

The Gypimack series consists of very deep, well drained soils that formed in alluvium derived from sandstone and shale. Gypimack soils are on treads and risers of stream terraces. Slopes range from 0 to 10 percent. Mean annual precipitation is about 203 mm, and mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Calcic Argigypsids

TYPICAL PEDON: Gypimack clay loam, 1 percent slope in an apple orchard at an elevation of 1,433 meters. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 13 cm; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; moderate fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; common very fine and fine tubular pores; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 15 cm thick)

Btk--13 to 25 cm; pale brown (10YR 6/3) clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots inside and between peds; common very fine and fine tubular pores; common faint clay films on faces of peds and few faint clay films on surfaces along pores; few fine calcium carbonate masses in the matrix; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 50 cm thick)

Btky1--25 to 51 cm; pink (7.5YR 7/4) clay loam, light brown (7.5YR 6/4) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots inside and between peds; common very fine and fine tubular pores; few faint clay films on faces of peds; common fine and medium calcium carbonate masses and few fine gypsum masses in the matrix; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary.

Btky2--51 to 81 cm; light yellowish brown (10YR 6/4) clay loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky parting to weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine tubular pores; few faint clay films on faces of peds; common fine and medium calcium carbonate masses and few fine gypsum masses in the matrix; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (combined thickness of Btky horizons is 0 to 69 cm)

Bky1--81 to 99 cm; light gray (2.5Y 7/2) gypsiferous sandy clay loam, light yellowish brown (2.5Y 6/4) moist; weak medium subangular blocky parting to weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine tubular pores; few fine calcium carbonate masses and common fine and medium gypsum masses in the matrix; slightly effervescent; slightly alkaline (pH 7.5); abrupt wavy boundary. (20 to 43 cm thick)

Bky2--99 to 200 cm; light yellowish brown (2.5Y 6/4) loam, light olive brown (2.5Y 5/4) moist; weak medium subangular blocky parting to weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine tubular pores; few very fine and fine calcium carbonate masses and common fine gypsum masses in the matrix; slightly effervescent; slightly alkaline (pH 7.7).

TYPE LOCATION: Mesa County; about 686 meters west and 518 meters south of the northeast corner of sec. 24, T 1S., R 1E; USGS Clifton, Colorado topographic quadrangle, NAD 27; UTM 22450 meters E, 26185 meter 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 15 percent gravel

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, loam or silty clay loam
Clay content: 25 to 32 percent
Rock fragments: 0 to 15 percent gravel
Sodium adsorption ratio: 0 to 4
Reaction: pH 7.9 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 or silty clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 10 to 25 percent
Gypsum content: 0 to 4 percent
Sodium adsorption ratio: 0 to 8
Reaction: pH 7.9 to 8.4

Btky 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 or silty clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 15 to 25 percent
Gypsum content: 5 to 10 percent
Sodium adsorption ratio: 0 to 8
Reaction: pH 7.8 to 8.4

Bky horizons
Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2, 3 or 4
Texture: sandy clay loam, loam or clay loam
Clay content: 22 to 30 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 5 to 20 percent
Gypsum content: 10 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 - treads and risers of stream terraces
Elevation - 1,372 to 1,768 meters
Slopes - 0 to 10 percent
Parent material - alluvium derived from sandstone and shale
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 Gyprockmesa and Fruita series which occur on similar landforms. Gyprockmesa soils do not have a gypsic horizon above 100 cm and they have cobbles and stones in the lower part of the subsoil. Fruita soils do not have a calcic horizon.

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

USE AND VEGETATION: Gypimack 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: Gypimack soils are of small 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 81 cm (Btk, Btky1 and Btky2 horizons)
Calcic horizon from - 25 to 81 cm (Btky1 and Btky2 horizons)
Gypsic horizon from - 25 to 200 cm (Btky1, Btky2, Bky1, and Bky2 horizons)
Particle-size control section from - 13 to 63 cm (Btk, Btky1, and Btky2 horizons)

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

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National Cooperative Soil Survey
U.S.A.