LOCATION LEYDEN             CO
Established Series
Rev. AEA/GB
02/97

LEYDEN SERIES


The Leyden series consists of moderately deep, well drained soils that formed in gravelly and cobbly alluvial materials derived from mixed sources overlying shale. Leyden soils are on side slopes and ridges and have slopes of 5 to 70 percent. The mean annual precipitation is about 16 inches and the mean annual temperature is about 47 degrees F.

TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Argiustolls

TYPICAL PEDON: Leyden cobbly clay loam - grassland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 3 inches; very dark grayish brown (10YR 3/2) cobbly clay loam, very dark brown (10YR 2/2) moist; weak fine granular structure; slightly hard, friable, sticky; 20 percent cobbles; neutral (pH 6.8); clear smooth boundary. (3 to 5 inches thick)

B1--3 to 8 inches; dark grayish brown (10YR 4/2) gravelly heavy clay loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, friable, sticky; 20 percent pebbles; neutral (pH 6.6); clear smooth boundary. (2 to 5 inches thick)

B21t--8 to 19 inches; brown to dark brown (10YR 4/3) gravelly heavy clay loam, dark brown (10YR 3/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, firm, sticky; common thin clay films on the faces of peds; 20 percent pebbles; neutral (pH 6.6); gradual smooth boundary. (4 to 11 inches thick)

B22t--19 to 29 inches; brown (10YR 5/3) gravelly clay, brown to dark brown (10YR 4/3) moist; weak coarse subangular blocky structure parting to weak medium subangular blocky; hard, firm, very sticky; common thin clay films on the faces of peds; 20 percent pebbles; neutral (pH 6.8); gradual wavy boundary. (7 to 12 inches thick)

B3--29 to 35 inches; light yellowish brown (2.5Y 6/4) gravelly heavy clay loam, olive brown (2.5Y 4/4) moist; weak coarse prismatic structure parting to weak coarse subangular blocky; hard, firm, very sticky; 20 percent pebbles; neutral (pH 7.0); clear smooth boundary. (4 to 7 inches thick)

Cr--35 inches; light yellowish brown (2.5Y 6/4) mudstone, olive brown (2.5Y 4/4) moist; mildly alkaline (pH 7.8).

TYPE LOCATION: Jefferson County, Colorado; approximately 3 miles west of Denver Federal Center; 140 feet east and 210 feet south of center of Sec. 7, T. 4 S., R. 69 W.

RANGE IN CHARACTERISTICS: Solum thickness and depth to the paralithic contact range from 20 to 40 inches. Rock fragments range from 15 to 35 percent by volume in the solum and range in size from 1/8 inch to 10 inches in diameter. Mean annual soil temperature ranges from 47 to 52 degrees F.

The A horizon has hue of 10YR or 2.5Y, value of 3 through 5, 2 or 3 moist, and chroma of 2 or 3. Reaction is neutral or mildly alkaline. Textures are modified with cobble and/or stones.

The B horizon has hue of 10YR or 2.5Y, value of 4 through 5, 3 or 4 moist, and chroma of 2 or 3. Reaction is neutral or mildly alkaline. It is gravelly clay loam, gravelly clay, or cobbly clay loam.

The C horizon, when present, has hue of 10YR or 2.5Y, value of 5 through 7, 4 through 6 moist, and chroma of 4 through 6. Reaction is mildly alkaline or moderately alkaline. It is gravelly clay loam, cobbly clay loam, or gravelly sandy clay loam.

The Cr horizon is weathered shale and sandstone.

COMPETING SERIES: These are Ashfork, Blackpipe, Boneek, Boquillas, Chapin, Collbran, Emigrant, Huggins, Kube, Loma, Nunn, Querc, Rednunn, Richfield, Ryus, Savo, Showlow, Sofia, Standley, Thunderbird, Torreon, and Wormser series. Ashfork, Chapin, Thunderbird, and Wormser soils have lithic contact at depths of 20 to 40 inches. Blackpipe, Boneek, Collbran, Kube, Loma, Nunn, Rednunn, Richfield, Ryus, Savo, Showlow, Sofia, Standley, and Torreon soils lack bedrock within depths of 40 inches. Boquillas soils have hues of 7.5YR and 5YR in the B2t horizon. Emigrant soils have free carbonates within a depth of 23 inches. Huggins soils have less than 15 percent coarse fragments in the control section. Querc soils are slightly acid.

GEOGRAPHIC SETTING: Leyden soils are on side slopes and ridges and have slopes of 5 to 70 percent. Elevations range from 4,000 to 6,500 feet. The soils formed in mixed gravelly and cobbly clay loam materials overlying shale and sandstone. The soils are in a semiarid climate with annual precipitation ranging from 13 to 17 inches. The mean annual temperature is 47 to 52 degrees F. The frost-free season is 125 to 145 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Nunn soils and the Denver, Kutch, and Midway soils. Denver and Kutch soils have less than 15 percent coarse fragments. Midway soils have bedrock at depths of less than 20 inches.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.

USE AND VEGETATION: Soils are used for grazing, recreation, wildlife, and community development. Native vegetation is blue grama, little bluestem, sideoats grama, needleandthread, western wheatgrass, forbs, and shrubs.

DISTRIBUTION AND EXTENT: Foothills and plains of eastern Colorado. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Golden Area Soil Survey, Jefferson County, Colorado, 1980.

REMARKS: Last updated by the state 4/80.


National Cooperative Soil Survey
U.S.A.