LOCATION YERMO CA+NVEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, calcareous, thermic Typic Torriorthents
TYPICAL PEDON: Yermo cobbly sandy loam, on a 3 percent north facing slope under creosotebush, bursage, hopsage, Mormon tea, yucca, and a few Joshua trees at 3,600 feet elevation. (Colors are for dry soil unless otherwise stated. When described the soil was dry throughout.)
A--0 to 10 inches; pale brown (10YR 6/3) cobbly sandy loam, dark brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine roots; few fine interstitial pores; about 15 percent pebbles and 10 percent cobbles; strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); abrupt smooth boundary. (6 to 12 inches thick)
C1--10 to 25 inches; very pale brown (10YR 7/3) gravelly sandy loam, pale brown (10YR 6/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common coarse and medium roots; common fine tubular pores; about 15 percent pebbles and 5 percent cobbles; violently effervescent with disseminated lime; moderately alkaline (pH 8.0); gradual smooth boundary. (10 to 15 inches thick)
C2--25 to 60 inches; light gray (10YR 7/2) very gravelly sandy loam, pale brown (10YR 6/3) moist; massive; soft, very friable, nonsticky and nonplastic; few fine roots; few very fine interstitial and tubular pores; about 55 percent pebbles and 15 percent cobbles; 1/8 to 1/4 inch lime coatings on bottom of coarse fragments; violently effervescent with disseminated lime; moderately alkaline (pH 8.0).
TYPE LOCATION: San Bernardino County, California; in Lucerne Valley about 0.6 miles southeast of Meridian Road on the turn to Pfizer Cement plant; in NE1/4 NW1/4 NE1/4 section 6, T.3 N., R.1 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 59 to 63 degrees F. and the soil temperature usually is not below 47 degrees F. at any time. The soil between the depths of about 8 and 24 inches is dry all the time from mid-spring to early winter and is not continuously moist for as long as 60 days.
The A horizon is pale brown, light yellowish brown, brown or yellowish brown (10YR 6/3, 6/4, 5/3, 5/4). It is cobbly sandy
loam or gravelly sandy loam and has 15 to 25 percent gravel and 5 to 15 percent cobbles. Structure is weak to moderate, very fine and fine subangular blocky. This horizon is strongly calcareous to very strongly calcareous with disseminated lime, and is moderately to strongly alkaline.
The C horizon is light gray or very pale brown (10YR 7/2, 7/3). It is gravelly sandy loam and has 15 to 25 percent gravel and up to 5 percent cobbles in the upper part. It is moderately to strongly alkaline and is strongly effervescent. The lower part of the horizon is similar to the upper part but has 40 to 60 percent gravel and up to 15 percent cobbles.
COMPETING SERIES: These are the Canutio, Emot and Ogral series. All of the competing soils are intermittently moist in the moisture control section in the summer. Emot soils have more than 50 percent silt in the fine earth fraction. Ogral soils have hue of 7.5YR or 5YR throughout.
GEOGRAPHIC SETTING: Yermo soils are on broad, alluvial fans and on older, faulted or uplifted uplands or valley floors at elevations of about 2,300 to 4,200 feet. Slopes range from from 0 to 50 percent. The soils formed in mixed, moderately coarse textured gravelly or cobbly alluvium. The climate is arid, with hot, dry summers and cool, somewhat moist winters. The mean annual precipitation is 4 to 6 inches, most of which occurs as rain in the winter. Some moisture falls occasionally as snow. The mean annual temperature
is 57 to 64 degrees F.; the mean January temperature is 46 degree F.; and the mean July temperature is 84 degrees F. The frost free season is 210 to 255 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arizo and Soboba soils. Arizo soils are loamy sand or coarser. Soboba soils have a xeric moisture regime and are loamy sand or coarser.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used for wildlife habitat and homesites. Vegetation is creosotebush, white bursage, scattered yucca and Joshua tree and annual grasses and forbs.
DISTRIBUTION AND EXTENT: Uplands and alluvial fans of Mojave Desert. The soils are moderately extensive. MLRA 30
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Bernardino County, California, Mojave River Area, 1978.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 10 inches.
Particle-size control section - 10 to 40 inches.