LOCATION MURANCH CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Aridic Haploxerolls
TYPICAL PEDON: Muranch loam, rangeland, on a slope of 50 percent under red brome, goldenbush and scattered junipers. (Colors are for dry soil unless otherwise noted. When described on May 22, 1984 the soil was very slightly moist below 7 inches.)
A1--0 to 3 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine roots; few very fine tubular and common very fine interstitial pores; mildly alkaline (pH 7.5); clear smooth boundary. (3 to 7 inches thick)
A2--3 to 15 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine and fine roots; common very fine and fine interstitial and common medium tubular pores; 5 percent pebbles; mildly alkaline (pH 7.5); gradual wavy boundary. (7 to 12 inches thick)
Bw--15 to 36 inches; light yellowish brown (10YR 6/4) very gravelly loam, dark yellowish brown (10YR 3/4) moist; massive; slightly hard, friable, sticky and plastic; few very fine and fine and common medium roots; few very fine tubular and interstitial pores; 40 percent pebbles and 20 percent cobbles; moderately alkaline (pH 8.0); gradual wavy boundary. (10 to 21 inches thick)
R--36 to 40 inches; very dark gray (10YR 3/1) hard fractured basalt, black (10YR 2/1) moist.
TYPE LOCATION: San Luis Obispo County, California; 35 paces west on ridge top where the power pole road makes a U-turn, then 35 paces north downhill. It is 2,300 feet east and 800 feet north of the southwest corner of section 33 T.11 N., R.25 W.; USGS Cuyama Tpopographic Quadrangle; lat. 34 degress, 59 minutes, 32 seconds N. and long. 119 degrees, 33 minutes, 7 seconds W.
RANGE IN CHARACTERISTICS: Depth to a lithic contact of basalt and solum thickness is 20 to 40 inches. The mean annual soil temperature varies from 60 to 67 degrees F. The moisture control section between the depths of 6 and 30 inches is moist in some part for at least 90 consecutive days from late December until April and is moist in all parts for 45 consecutive days between mid January and mid March. The soil is dry in all parts for about 225 days. The soil temperature is always above 47 degrees F. Clay content is 20 to 27 percent throughout the profile. The profile is mildly or moderately alkaline throughout.
The A horizon is 10YR 5/2 or 5/3. Moist color is 10YR 3/2 or 3/3. Gravel content is 0 to 5 percent and cobble content is 0 to 5 percent.
The B horizon is 10YR 6/3 or 6/4; 7.5YR 6/3. Moist color is 10YR 3/3, 3/4, 4/2, 4/3 or 4/4. Gravel content is 25 to 45 percent and cobble content is 15 to 30 percent.
Some pedons have C horizons above the lithic contact.
COMPETING SERIES: This is the Jenks(T) and Livermore series in another family. Jenks(T) soils have less than 15 percent gravel throughout. Livermore soils do not have a lithic contact.
GEOGRAPHIC SETTING: Muranch soils are on hills and mountains. These soils formed in material weathered from basalt. Slopes are 30 to 75 percent. Elevation is 2800 to 4100 feet. The climate is semi-arid with warm dry summers and cool moist winters. The mean annual precipitation is 8 to 10 inches. The mean annual temperature is 58 to 62 degrees F. Frost-free season is 175 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beam, Bellyache (T), Panoza (T), and Semper (T) soils. Beam soils are less than 20 inches deep and are loamy. Panoza(T) and Semper(T) soils are coarse-loamy. Bellyache (T) soils have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium on the steep slopes or high on the steeper slopes. Permeability is moderate.
USE AND VEGETATION: Used for livestock grazing. The vegetation is red brome, annual fescue and narrowleaf goldenbush.
DISTRIBUTION AND EXTENT: These soils are in the Caliente Range of California. MLRA 15. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: San Luis Obispo County, California. Carrizo Plain Soil Survey Area, 1984. The name is from the nearby MU Ranch.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: Zone from the surface to a depth of 15 inches(A1,A2).
Cambic horizon: Zone from about 15 inches to 36 inches (B). Horizon has stronger chroma than the A and R horizons.
Lithic contact: A contact of hard basalt is at 36 inches (R).