LOCATION TECOPA CA+NV
Established Series
Rev. YHH
12/2015
TECOPA SERIES
The Tecopa series consists of very shallow soils formed in residuum and colluvium weathered from quartzite, schists, and gneiss. Tecopa soils are on low hills and low mountain side slopes with a gradient of 15 to 75 percent. The mean annual precipitation is about 4 to 8 inches and the mean annual air temperature is about 60 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, calcareous, thermic Lithic Torriorthents
TYPICAL PEDON: Tecopa very gravelly sandy loam, desert rangeland. (Colors are for dry soil unless otherwise noted.) 75 percent of surface is covered with gravel and cobble.
A1--0 to 1 inch; pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 5/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; few fine and very fine roots; common very fine interstitial pores; 65 percent gravel; strongly effervescent, moderately alkaline (pH 8.3); clear smooth boundary. (1/2 to 2 inches thick)
C1--1 to 6 inches; light yellowish brown (10YR 6/4) very gravelly sandy loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few fine and very fine roots; common very fine and fine interstitial pores; 50 percent gravel and cobbles; strongly effervescent, moderately alkaline (pH 8.3); clear wavy boundary. (1 to 7 inches thick)
C2ca--6 to 8 inches; very pale brown (10YR 7/3) very gravelly sandy loam, brown (10YR 5/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; few fine and very fine roots; common fine interstitial pores; 65 percent gravel and cobbles; violently effervescent; moderately alkaline (pH 8.4); abrupt irregular boundary. (0 to 3 inches thick)
R--8 inches; extremely hard quartzite with lime coatings in rock fractures.
TYPE LOCATION: Inyo County, California; in the SW1/4 of SE1/4 section 21, T.20N., R.8E.
RANGE IN CHARACTERISTICS: The depth to bedrock ranges from 2 to 10 inches. The estimated mean annual soil temperature ranges from 59 to 72 degrees F. The soils are usually dry for 6 months or more during most years, mainly during spring, summer, and fall months and are low in organic matter. Rock fragments range from 35 to 90 percent on the surface and from 35 to 80 percent throughout the profile. Either gravel or cobbles dominate, but a few stones may also be present. The pH range is moderately alkaline. The soil is calcareous throughout and is mainly disseminated. Lime coatings on rock fragments and in bedrock fractures an also occur.
The A horizon has hue of 7.5YR or 10YR, value of 6 or 7 dry, 4 or 5 moist, and chroma of 3 through 6. It is very gravelly or very cobbly sandy loam or loam.
The C horizons have hues of 10YR or 7.5YR, value of 6 or 7 dry, 5 or 6 moist, and chroma of 3 or 4. They are gravelly or very cobbly sandy loam or loam. A Cca horizon is present in deeper profiles but may be lacking in shallower profiles.
COMPETING SERIES: These are the
Akela,
St. Thomas, and
Theriot series. Akela soils are 10 to 20 inches deep over basalt. St. Thomas and Theriot soils have carbonatic mineralogy. Theriot soils also have temperatures colder than 59 degrees F.
GEOGRAPHIC SETTING: Tecopa soils are on low hills and low mountain side slopes at elevations of 1,500 to 5,000 feet. Slopes are 15 to 75 percent. The soils formed in residuum and colluvium from quartzite, gneiss, and schist. The climate is arid, with an estimated precipitation is from 4 to 8 inches. The mean annual temperature is between 59 and 72 degrees F.; the average January temperature is about 38 to 41 degrees F.; and the average July temperature is about 79 to 85 degrees F. The frost free season is about 200 to 260 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
Arizo,
Bitter,
Blackmount,
Grapevine, and
Nickel soils and the competing
St. Thomas and
Theriot soils. Except for the competing soils, they lack bedrocks at depths of less than 10 inches.
DRAINAGE AND PERMEABILITY: Well rained; medium to rapid runoff; permeability is moderate.
USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. Vegetation is creosotebush, yucca, cacti, white bursage, Morman tea and blackbrush.
DISTRIBUTION AND EXTENT: Inyo and San Bernardino Counties, California. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA
SERIES ESTABLISHED: Kingston-Amargosa Area, parts of Inyo and San Bernardino, California, 1979.
Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 11/2001. ET
National Cooperative Soil Survey
U.S.A.