LOCATION GOLD CREEK COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, frigid Vertic Endoaquolls
TYPICAL PEDON: Gold Creek silty clay loam, grassland. (Colors are for dry soil unless otherwise noted.)
O1--2 to 0 inches; undecomposed organic material consisting mainly of the remains of water-tolerant plants and sedges. (0 to 3 inches thick)
A11--0 to 9 inches; gray (10YR 5/1) silty clay loam, black (10YR 2/1) moist; moderate very fine granular structure; soft, very friable; slightly sticky and slightly plastic; calcareous; very strongly alkaline; gradual wavy boundary. (6 to 12 inches thick)
A12--9 to 20 inches; dark gray (2.5Y 4/1) silty clay, black (10YR 2/1) moist; common medium distinct olive brown (2.5Y 4/6) moist mottles; weak coarse subangular blocky structure that parts to fine granules; slightly hard, very friable, sticky and plastic; peds are very hard, firm; calcareous; very strongly alkaline; gradual wavy boundary. (0 to 12 inches thick)
B2g--20 to 50 inches; light gray (10YR 7/2) silty clay, light brownish gray (10YR 6/2) moist; common medium distinct olive brown (2.5Y 3/1) moist mottles; massive; extremely hard, very firm, sticky and plastic; calcareous; very strongly alkaline.
TYPE LOCATION: Gunnison County, Colorado; SW 1/4 of Sec. 34, T. 49 N., R. 3 E.
RANGE IN CHARACTERISTICS: The Gold Creek soils usually are calcareous at the surface, but depth to uniformly calcareous material ranges from 0 to 10 inches. Conductivity ranges from 0 to 14 millimhos in a major part of the control section. Exchangeable sodium ranges from 15 to 30 percent in most of the control section. Thin organic horizons generally occur at the surface but are absent in some pedons. No continuous concentrated horizons of visible secondary calcium carbonate and/or sulfate are present within the control section, but some visible carbonate occurs at any depth as a characteristic of the parent material. The control section is usually heavy silty clay loam or silty clay and has 35 to 60 percent clay, 10 to 50 percent silt, and 10 to 45 percent sand. Rock fragments range from 0 to 35 percent in a major part of the control section and are mainly less than 3 inches in diameter but range from 1/8 to 10 inches in diameter. COLE ranges from .05 to .09 and total potential extensibility exceeds 2.4 inches in the upper 50 inches. The soils develop wide cracks in some seasons of most years. Mean annual soil temperature is 37 degrees F., and mean summer soil temperature is 48 degrees F. when undrained and without an 0 horizon.
The A horizon has hue of 5Y through 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of neutral through 2. It has distinct to prominent mottling in some part. This horizon ranges from mildly to very strongly alkaline.
The B2 horizon has hue of 5Y through 7.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of neutral through 2 and has distinct or prominent mottles. It is strongly or very strongly alkaline.
A IIC horizon of sand and gravel underlies the solum at depths of 40 to 60 inches in many pedons.
COMPETING SERIES: These are the Grano and Ludden series. Grano and Ludden soils lack B2 horizons and have less than 15 percent exchangeable sodium. Also, Ludden soils have continuous horizons of secondary calcium carbonate accumulation.
GEOGRAPHIC SETTING: These soils are on nearly level to slightly concave portions of flood plains or low terraces. The soils formed in fine textured very strongly alkaline alluvium derived mainly from sedimentary rock. At the type location, the average annual precipitation is 12 inches with peak periods of precipitation during the spring and summer. The annual temperature is 50 degrees F., summer temperature is 50 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Irim and Big Blue soils. Irim soils have control sections with less than 35 percent clay and have more than 35 percent rock fragments. Big Blue soils have less than 25 percent exchangeable sodium and have less volume change.
DRAINAGE AND PERMEABILITY: Poorly to very poorly drained; slow runoff to ponded; slow permeability.
USE AND VEGETATION: These soils are used as native pastureland and for native hay crops. Native vegetation is mainly wheatgrass, some fescue, sedges, and rushes.
DISTRIBUTION AND EXTENT: Mountain valleys of central Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gunnison County, Colorado, 1974.
REMARKS: Last updated by the state 2/75.