LOCATION TARRYALL COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Torriorthentic Haplustolls
TYPICAL PEDON: Tarryall gravelly loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, slightly sticky, slightly plastic; 20 percent limestone gravel; calcareous; moderately alkaline; clear smooth boundary. (7 to 20 inches thick)
AC--10 to 18 inches; light brownish gray (2.5Y 6/2) gravelly loam, dark grayish brown (2.5Y 4/2) moist; weak medium subangular blocky structure that parts to medium granules; hard, very friable, slightly sticky, slightly plastic; 20 percent limestone gravel; calcareous; moderately alkaline; gradual smooth boundary. (6 to 20 inches thick)
C--18 to 30 inches; light brownish gray (2.5Y 6/2) gravelly loam, grayish brown (2.5Y 5/2) moist; massive; hard, very friable, slightly sticky, slightly plastic; 20 percent limestone fragments; calcareous; moderately alkaline; abrupt wavy boundary. (10 to 18 inches thick)
R--30 to 60 inches; hard limestone bedrock.
TYPE LOCATION: Douglas County, Colorado; 650 feet west and 700 feet north of the SE corner of Sec. 14, T. 95., R. 68 W.
RANGE IN CHARACTERISTICS: Depth to uniformly calcareous material ranges from 0 to 10 inches and is less than one-half the thickness of the mollic epipedon. Exchangeable sodium ranges from 0 to 15 percent in most subhorizons of the control section, and there is no subhorizon as much as 3 inches thick above the bedrock that has as much as 15 percent. Depth to the lithic contact ranges from 20 to 40 inches. The control section is usually gravelly loam or clay loam and has 18 to 35 percent clay, 20 to 50 percent silt, and 20 to 52 percent sand with less than 35 percent being fine or coarser sand. Rock fragments range from 15 to 35 percent by volume in a major part of the control section and are mainly less than 3 inches in diameter but range from 1/8 inch to 19 inches in diameter. The calcium carbonate equivalent of the whole soil including rock fragments less than 3 inches in diameter ranges from 8 to 39 percent and remains constant or increases with increasing depth. Mean annual soil temperature is 49 degrees F., and mean summer soil temperature is 64 degrees F.
The A horizon has hue of 2.5Y through 7.5YR, value of 3 through 5 dry, 2 or 3 moist, and chroma of 1 through 3. It is mildly or moderately alkaline.
The C horizon has hue of 2.5Y through 7.5YR. It is moderately or strongly alkaline.
COMPETING SERIES: These are the Connerton, Hayness, Nucla and Paymaster series. All of these soils lack bedrock above depth of 40 inches.
GEOGRAPHIC SETTING: Tarryall soils are on moderate to steeply sloping hills and ridges where limestone bedrock lies moderately close to the surface. The soil formed in parent materials weathered residually from the limestone or locally transported downslope. At the type location the average annual precipitation is approximately 17 inches, with peak periods of precipitation in the spring and summer.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the LaPorte and Penrose soils. LaPorte and Penrose soils have a lithic contact at depths of less than 20 inches. Also, Penrose soils lack a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff, moderate permeability.
USE AND VEGETATION: These soils are used primarily as native pastureland; however, they are tilled locally. Adapted native vegetation is mainly Indian ricegrass, sideoats grama, needle-and-thread grass, Junegrass, blue grama, little bluestem, and mountain-mahogany.
DISTRIBUTION AND EXTENT: The foothill areas of eastern and central Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Douglas County, Colorado, 1974.
REMARKS: OSED scanned by NSSQA and cleaned up by Colorado. Last revised by state on 8/74.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Lakewood MLRA office, without review of the soil series property data. The remainder of this document has not been updated.