LOCATION GIBBLER COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Ustic Paleargids
TYPICAL PEDON: Gibber fine sandy loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; light reddish brown (5YR 6/4) fine sandy loam, reddish brown (5YR 4/4) moist; moderate very fine granular structure; soft, very friable; neutral (pH 6.8); clear smooth boundary. (3 to 5 inches)
A2--4 to 6 inches; pink (5YR 7/3) light fine sandy loam, reddish brown (5YR 5/3) moist; moderate thin platy structure that parts to strong fine granules; soft, very friable; neutral (pH 6.8); abrupt smooth boundary. (0 to 3 inches thick)
B2t--6 to 20 inches; reddish brown (5YR 4/4) moist; strong fine prismatic structure that parts to strong fine angular blocks; slightly hard, very plastic; individual peds are extremely hard; thin continuous waxy coatings on peds and in root channels; noncalcareous; slightly alkaline (pH 7.4); clear wavy boundary. (9 to 24 inches thick)
B3ca--20 to 24 inches; pink (5YR 8/4) channery heavy clay loam, light reddish brown (5YR 6/4) moist; weak medium angular blocky structure; hard and extremely hard, very plastic; 15 to 20 percent sandstone fragments; few thin wax-like coatings on some peds and in root channels; some visible secondary calcium carbonate as concretions, and thin seams or streaks; moderately alkaline (pH 8.4); abrupt wavy boundary. (3 to 8 inches thick)
R--24 inches; hard sandstone bedrock.
TYPE LOCATION: Mesa Country, Colorado; SW1/4, Sec. 7, T. 49 S., R. 17 W.
RANGE IN CHARACTERISTICS: Depth to calcareous material ranges from 10 to 20 inches, thickness of the solum ranges from 15 to 40 inches, and depth to the underlying bedrock ranges from 20 to 40 inches. Organic matter of the upper 15 inches is approximately .6 percent and the sand/clay ratio is typically less than 1. The soil is 90 to 100 percent base-saturated. Cation exchange capacity ranges from 70 to 90 milliequivalents per 100 grams of clay. Typically, the solum extends to bedrock but in some pedons a thin C horizon is present between the solum and bedrock. Rock fragments range from 0 to 15 percent but are usually less than 5 percent throughout most of the solum. They are most numerous in the horizon immediately above the bedrock. Mean annual soil temperature ranges from 47 degrees to 58 degrees F. and mean summer soil temperature ranges from 60 degrees to 78 degrees F. These soils are usually moist in some part between depth of 4 and 12 inches for approximately 1/4 to 1/2 of the time the soil temperature is above 41 degree F. and are moist in all parts between depths of 4
and 12 inches for less than 60 cumulative days during the 120 days following the winter solstice.
The A1 horizon has hue of 7.5YR or 5YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 through 4. It is neutral or mildly alkaline (pH 6.6 to 7.6). Typically, the horizon has fine granular structure but it has weak subangular blocky structure in some pedons. It is soft or slightly hard.
The A2 horizon has hue of 7.5YR through 2.5YR, value of 7 or 8 dry, 5 or 6 moist, and chroma of 2 through 4. It is neutral or mildly alkaline (pH 6.6 to 7.6). This horizon is soft or slightly hard.
The B2t horizon has hue of 5YR or 2.5YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 3 through 5. It is typically light clay and has 35 to 50 percent clay, 15 to 40 percent silt, and 20 to 45 percent sand, with more than 15 percent being fine or coarser sand. This horizon is neutral or mildly alkaline (pH 7.0 to 7.8). It has some oriented clay films on peds, in root channels, or as coatings on rock fragments.
The Cca horizon has hue of 5YR or 2.5YR. It is moderately or strongly alkaline (pH 8.0 to 8.6) and has approximately 4 to 12 percent calcium carbonate equivalent.
COMPETING SERIES: These are the Adena, Bidman, Big Horn, Briggsdale, and Campo series. Adena, Bidman, Big Horn, and Campo soils have bedrock at depths greater than 40 inches. Briggsdale soils have a paralithic contact at depths of 20 to 40 inches.
GEOGRAPHIC SETTING: Gibbler soils are on nearly level to moderately sloping upland hills and ridges. Slope gradients usually range from 0 to 10 percent. The soils formed in thin deposits of reddish brown eolian sediments derived from redbeds overlying sandstone bedrock. At the type location average annual precipitation is 15 inches, with peak periods of precipitation during the spring and early summer. Mean annual temperature is 48 degrees F. and mean summer temperature is 63 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Potts and Witt soils. Potts and Witt soils lack abrupt textural changes and have light clay loam, light silty clay loam, heavy loam, or heavy silt loam argillic horizons.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; slow permeability.
USE AND VEGETATION: These soils are used principally as native pastureland. Native vegetation is galleta grass, Indian ricegrass, mountain bluegrass, pinon, and juniper.
DISTRIBUTION AND EXTENT: The western slope areas of Colorado. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lower Colorado Area, Colorado, 1970.
REMARKS: Last updated by the state 12/73.
In October 2000, taxonomic classification was converted to the closest match found in Soil Taxonomy, Second Edition 1999. No update was made to horizon nomenclature, competing series section, etc. Other placements may be more appropriate after a complete update.