LOCATION MEXISPRING CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, nonacid, mesic, shallow Typic Torriorthents
TYPICAL PEDON: Mexispring very cobbly sandy loam, on a south facing convex slope of 15 percent under Joshua trees and buckwheat at 6,600 feet elevation. (Colors are for dry soil unless otherwise stated. When described the soil was dry throughout.) The soil surface is covered with 20 percent pebbles, 15 percent cobbles, and 1 percent stones.
A1--0 to 1 inch; pale brown (10YR 6/3) very cobbly sandy loam, brown (10YR 4/3) moist; weak very thick platy structure; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; common fine vesicular and interstitial pores; 20 percent pebbles, 15 percent cobbles, and 1 percent stones; moderately alkaline (pH 8.0); clear wavy boundary. (1 to 3 inches thick)
A2--1 to 6 inches; pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few thin reddish brown coatings on rock fragments; few very fine roots; common medium interstitial pores; 50 percent pebbles, 10 percent cobbles; moderately alkaline (pH 8.0); clear wavy boundary. (3 to 11 inches thick)
Cr--6 to 15 inches; strongly weathered and fractured granitic rock, slakes when soaked in water.
TYPE LOCATION: Inyo County, California; Saline Valley; 4.5 miles northeast of Jackass Spring along the Hunter Mountain Road; in an unsurveyed area; 2 miles west of the Death Valley Monument southwest boundary and about 1 mile south of the Ulida Flat; approximately 36 degrees 37 minutes north latitude and 117 degrees 31 minutes west longitude, NAD27.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact ranges from 4 to 14 inches. the mean annual soil temperature is about 55 degrees F. This soil is dry from June through early November.
The A1 horizon has dry color of 10YR 6/2, 6/3 or 7.5YR 6/2 and moist color of 10YR 4/3, 4/4, 5/3; 7.5YR 5/2 or 5/4. Texture ranges from very gravelly sandy loam to very cobbly sandy loam and fine sandy loam. Rock fragments of 2 mm to 25 cm diameter range from 35 to 80 percent.
The A2 horizon is very gravelly sandy loam or very gravelly fine sandy loam. Rock fragments of 2 mm to 25 cm diameter range from 35 to 80 percent.
COMPETING SERIES: These are Goldbutte and Uripnes series.
Goldbutte soils have horizons with illuvial clay accumulation. Uripnes soils have mean annual soil temperature of 47 to 54 degrees F.
GEOGRAPHIC SETTING: Mexispring soils are on hills and mountains. Slopes are 15 to 85 percent. The soils formed in material weathered from granitic rocks. The bedrock consists of weathered granite, granodiorite and quartz monzonite which slakes when soaked in water. Fractures are widely spaced, more than 20 cm, and are less than 2 mm wide. The weathered bedrock continues below a depth of 60 inches. Elevations are 4,000 to 6,700 feet. The climate is arid with hot, dry summers with infrequent showers of short duration and cool slightly moist winters. The average annual precipitation is 6 to 8 inches. The mean annual temperature is 53 degrees F.; the mean January temperature is 40 degrees F.; and the mean July temperature is 80 degrees F. The frost free season is 185 to 235 days.
GEOGRAPHICALLY ASSOCIATED SOILS: There are the Ulida and Panamint soils. Ulida soils have an argillic horizon. Panamint soils are 20 to 40 inches deep to a paralithic contact and have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Mexispring soils are used mainly for watershed, wildlife habitat, recreation, and rangeland. The native vegetation is primarily green Mormon-tea, California desert buckwheat, needlegrass, Joshua tree, big sagebrush, and bitterbrush.
DISTRIBUTION AND EXTENT: Mountains of northern California Desert. Small extent. MLRA 29.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Inyo County, California, Saline Valley Area, 1980.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 6 inches (A1 and A2 horizons).
Paralithic contact - The boundary at 6 inches to underlying soft, weathered bedrock (Cr layer).
The nature of the weathered bedrock should be evaluated to determine whether slaking is typical for the material. If the material does not slake, it would fit the concept for paralithic materials and not densic materials.
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 Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.