LOCATION DENBAR CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Pachic Argixerolls
TYPICAL PEDON: Denbar clay loam - on a west facing 6 percent slope under Idaho fescue, bottlebrush squirreltail and green rabbitbrush at 4,280 feet elevation. (When described on July 13, 1978, the soil was dry throughout.)
A1--0 to 3 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; soft, very friable, sticky and plastic; many very fine roots; many very fine interstitial pores; 1 percent stones; mildly alkaline (pH 7.6); clear smooth boundary. (2 to 5 inches thick)
A2--3 to 8 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; soft, very friable, sticky and plastic; common very fine and fine roots; many very fine interstitial pores; 2 percent stones, 3 percent cobbles, 3 percent pebbles; moderately alkaline (pH 8.0); clear smooth boundary. (5 to 6 inches thick)
Bt1--8 to 13 inches; grayish brown (10YR 5/2) clay, very dark grayish brown (10YR 3/2) moist; strong fine subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and roots; many very fine interstitial pores; many thin clay films on peds; 1 percent stones, 3 percent cobbles, 3 percent pebbles; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 7 inches thick)
Bt2--13 to 22 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; strong medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and fine roots; common very fine interstitial pores; many moderately thick clay films on peds; 1 percent stones, 3 percent cobbles, 3 percent pebbles; moderately alkaline (pH 8.0); clear smooth boundary. (9 to 11 inches thick)
Bt3--22 to 29 inches; brown (7.5YR 5/4) clay loam, dark brown (7.5YR 4/4) moist; strong medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and fine roots; common very fine and fine interstitial pores; common thin clay films on peds; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 8 inches thick)
2C1--29 to 34 inches; pale brown (10YR 6/3) sandy loam, brown (10YR 4/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; common fine roots; few very fine interstitial pores; strongly effervescent with disseminated lime; moderately alkaline (pH 8.2); clear wavy boundary. (5 to 8 inches thick)
2C2--34 to 48 inches; very pale brown (10YR 7/3) sandy loam, brown (10YR 4/3) moist; massive; soft, very friable, slightly sticky and slightly plastic, few fine roots; few very fine interstitial pores; violently effervescent with disseminated lime; 10 percent pebbles; moderately alkaline (pH 8.2); abrupt smooth boundary. (10 to 15 inches thick)
3Cqkm--48 to 60 inches; light yellowish brown (10YR 6/4) indurated duripan, dark yellowish brown (10YR 3/4) moist; massive; extremely hard, extremely firm and brittle; opal laminar cap is 1 to 2 millimeters thick; strongly effervescent with lime occurring in seams throughout this horizon; moderately alkaline (pH 8.2).
TYPE LOCATION: Siskiyou County, California; 400 feet north, 2,115 feet east of the southwest corner of section 1, T. 46 N., R. 2 E.
RANGE IN CHARACTERISTICS: The thickness of the solum ranges from 25 to 37 inches. Depth to the duripan ranges from 40 to 60 inches. The mean annual soil temperature ranges from 48 to 52 degrees F. The soil temperature at a depth of 20 inches is above 41 degrees F. from about March 15 to December 1 (225 days) and is above 47 degrees F from the about April 15 to November 15 (210 days). The soil between depths of 6 to 16 inches is dry in all parts from about July 1 to November 1 (120 days). The soil moisture control section is dry less than half the time the soil temperature is above 41 degrees F. Mollic epipedon ranges from 20 to 29 inches. Rock fragments make up 0 to 15 percent of the soil profile. Stones and cobbles cover 0 to 3 percent of the soil surface.
The A horizon has dry color of 10YR 5/2, 5/3 or 7.5YR 5/2 and moist color of 10YR 3/2 or 7.5YR 3/2. Clay content ranges from 27 to 35 percent. Reaction ranges from mildly to moderately alkaline.
The Bt1 and Bt2 horizons have dry color 10YR 4/2, 5/2, 5/3 or 7.5YR 5/4 and moist color of 10YR 3/2 or 3/3. Clay content ranges from 35 to 50 percent. Texture is clay loam or clay. Reaction ranges from mildly to moderately alkaline.
The Bt3 has dry color of 10YR 6/3 or 7.5YR 5/4 and moist color of 10YR 4/3, 4/4 or 7.5YR 4/4. Clay content ranges from 35 to 50 percent. Texture is clay loam or clay. Reaction ranges from mildly alkaline to moderately alkaline.
The C horizon has dry color of 10YR 6/3, 7/3 or 7.5YR 6/4 and moist color of 10YR 4/3; 7.5YR 4/4 or 5/4. Clay content ranges from 10 to 20 percent.
COMPETING SERIES: These are the Deshler, Deter, Jacknife, Medford, Mindego and Nebeker series in the same family and the Geoconda series in another family. Deshler soils are 20 to 40 inches to bedrock and are dry 45 to 70 consecutive days. Deter soils are dry 90 to 110 consecutive days, have a solum thickness greater than 60 inches and lack a duripan. Geoconda soils are calcareous in the Bt horizons, have solum thickness greater than 40 inches, lack a duripan and are dry for 60 to 75 consecutive days. Jacknife soils are moist in some part of the moisture control section for more than 90 days when the soil temperature is above 47 degrees F., are dry for 60 to 80 consecutive days and have cobbly clay or cobbly clay loam argillic horizons with more than 15 percent rock fragments. Medford soils have soil temperature of 54 to 57 degrees F. and are dry 45 to 80 consecutive days and have a solum 40 to 60 inches thick. Mindego soils have a soil temperature of 55 degrees F. or warmer, have a comparatively small summer-winter (9 degrees F. to 11 degrees F.) temperature change and are slightly acid or neutral. Nebeker soils are dry for 60 to 75 consecutive days, are medium acid to neutral in the solum and have a solum that ranges from 40 to 60 inches thick.
GEOGRAPHIC SETTING: Denbar soils are on terraces. Slopes are 0 to 9 percent. The soils formed in alluvium weathered from rhyolite, tuff, basalt and other extrusive igneous rocks. Elevations are 4,200 to 4,800 feet. The climate is semi-arid with warm dry summers and cool moist winters. The average annual precipitation is about 13 to 15 inches. Snowfall is 20 to 30 inches. The average annual temperature is about 46 to 48 degrees F. The average January temperature is about 29 to 31 degrees F. and the average July temperature is about 64 to 66 degrees F. Frost-free season is about 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Capona, Demox, Lequieu, Lorella and Salisbury soils. Capona and Salisbury soils are moderately deep. Lequieu and Lorella soils are shallow. Demox soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained, slow to medium runoff, slow permeability.
USE AND VEGETATION: Denbar soils are used as rangeland. Vegetation is bluebunch wheatgrass, Idaho fescue, and thurber needlegrass.
DISTRIBUTION AND EXTENT: North central California. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Siskiyou County, California, 1986.
REMARKS: Diagnostic horizons and features recognized in the pedon are: Mollic epipedon--the zone from the surface of the soil to a depth of 22 inches. (A1, A2, Bt1, Bt2).
Argillic Horizon--The zone from 8 to 29 inches (Bt1, Bt2, Bt3).
Texture Control: Zone from 8 to 28 inches. The textural control section averages 41.8 percent clay.
OSED scanned by SSQA. Last revised by state on 4/86.