LOCATION DOCT CO+MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Haplocryolls
TYPICAL PEDON: Doct gravelly loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 9 inches; grayish brown (2.5YR 5/2) gravelly heavy loam, very dark grayish brown (2.5Y 3/2) moist; weak fine subangular blocky structure that parts to strong fine crumbs and granules; soft, very friable; 15 percent limestone and shale fragments; noncalcareous; mildly alkaline; clear smooth boundary. (6 to 15 inches thick)
C1--9 to 14 inches; grayish brown (2.5Y 5/2) gravelly light clay loam, dark grayish brown (2.5Y 4/2) moist; moderate fine subangular blocky structure; slightly hard, very friable; 25 percent limestone and shale fragments; noncalcareous except for gravel fragments; neutral (pH of matrix material 7.2); clear smooth boundary. (4 to 8 inches thick)
C2--14 to 30 inches; olive gray (5Y 5/2) gravelly light clay loam, olive gray (5YR 4/2) moist; massive; hard, very friable; 30 percent limestone and shale fragments; noncalcareous except for gravel fragments; neutral (pH of matrix 7.0); gradual smooth boundary. (8 to 17 inches thick)
R--30 to 40 inches; interbedded limestone and slaty shale.
TYPE LOCATION: Gunnison County, Colorado; in Sec. 11, T. 14 S., R. 83 W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 7 to 15 inches thick, and depth to bedrock ranges from 20 to 40 inches. Typically these soils are noncalcareous throughout, but they are weakly calcareous immediately above the bedrock in some locations. Organic carbon in the mollic epipedon ranges from 1 to 6 percent and decreases uniformly as depth increases. The soil is 90 to 100 percent base saturated with exchangeable sodium and potassium remaining constant or increasing slightly as depth increases. Typically the soils have no visible accumulation of secondary calcium carbonate except that there are weak coatings of calcium carbonate on the underside of limestone and shale fragments in the last few inches above the bedrock in some pedons. The control section is usually light clay loam or heavy loam and has 18 to 35 percent clay, 20 to 55 percent silt, and 20 to 50 percent sand. Coarse fragments range from 15 to 35 percent. Bulk calcium carbonate equivalent ranges from 6 to 10 percent due to limestone gravel. The average annual soil temperature is 30 degrees F, and the average summer soil temperature is 45 degrees F.
The A1 horizon has hue of 2.5Y or 10YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. It usually has strong granular or crumb structure, but it has weak subangular blocky structure in some pedons. This horizon is soft or slightly hard. It is neutral or mildly alkaline.
The C horizon has hue of 5Y through 10YR. It is typically massive or weak subangular blocky. This horizon is slightly hard or hard. It ranges from neutral to moderately alkaline.
COMPETING SERIES: These are the Dewville, Emerald, Ptarmigan, Red Cloud, Teton, and Yeoman series. All of these, except the Ptarmigan soils, lack bedrock within depth of 40 inches and all (including Ptarmigan soils) have mean annual soil temperature warmer than 32 degrees F.
GEOGRAPHIC SETTING: The Doct soils are on alpine hills, ridges, and mountainsides above timber line. Slope gradient ranges from 2 to 60 or more percent. The soils formed in materials weathered from underlying limestone and shale. At the type location the average annual precipitation is 20 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Almont and Haverly soils and the competing Ptarmigan soils. Almont soils are poorly to somewhat poorly drained and have common mottles in and below the lower part of the A1 horizon. Haverly soils are very strongly acid.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability when soil is not frozen.
USE AND VEGETATION: These soils are used principally as native pastureland or for recreational purposes. Native vegetation is mainly kobresia, sedges, alpine blue grass, tufted hairgrass, bistort, cinquefoil, and willow.
DISTRIBUTION AND EXTENT: Alpine mountainous areas of central Colorado. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gunnison County, Colorado, 1974.
REMARKS: Last updated by the state 9/74.