LOCATION CYVAR CAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Typic Durixeralfs
TYPICAL PEDON: Cyvar loam - on a northeast facing slope of 6 percent. Vegetation is red brome, filaree, rattail fescue, and Ephedra. The elevation is 2,190 feet. (Colors are for dry soil unless otherwise stated. When described, December 21, 1992, the soil was slightly moist to 7 inches. 10 percent duripan fragments (2 to 75mm) on surface.)
A--0 to 2 inches; light yellowish brown (10YR 6/4) loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular and interstitial pores; strongly effervescent, carbonates disseminated, violently effervescent, carbonates segregated as 5 percent common fine concretions, calcium carbonate equivalent is 10 percent; electrical conductivity is 5.1 decisiemens per meter; sodium adsorption ratio is 5; 2 percent gravel; slightly alkaline (pH 7.5); abrupt smooth boundary. (1 to 4 inches thick)
Bt--2 to 7 inches; light yellowish brown (10YR 6/4) loam, dark yellowish brown (10YR 4/4) moist; moderate very coarse subangular blocky structure parting to moderate coarse subangular blocky; slightly hard, very friable, moderately sticky and moderately plastic; common very fine roots; common very fine and few fine tubular pores, and common very fine interstitial pores; few thin clay films lining pores, on faces of peds and bridging mineral grains; strongly effervescent, carbonates disseminated , violently effervescent, carbonates segregated as 5 percent fine concretions; calcium carbonate equivalent is 16 percent; electrical conductivity is 0.5 decisiemens per meter; sodium adsorption ratio is 4; 2 percent gravel; slightly alkaline (pH 7.7); abrupt wavy boundary. (0 to 4 inches thick)
Btk1--7 to 13 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/6) moist; moderate coarse subangular blocky structure paring to weak medium subangular blocky; slightly hard, very friable, moderately sticky and moderately plastic; few very fine and very few fine roots; common very fine and few fine tubular and common very fine interstitial pores; few thin clay films lining pores, on faces of peds, and bridging mineral grains and very few moderately thick clay films lining pores and on faces of peds; strongly effervescent, carbonates disseminated, violently effervescent, carbonates segregated as 15 percent fine and medium concretions, threads, and soft masses; calcium carbonate equivalent is 20 percent; electrical conductivity is 0.4 decisiemens per meter; sodium adsorption ratio is 3; 2 percent gravel; moderately alkaline (pH 7.9); clear wavy boundary. (3 to 8 inches thick)
Btk2--13 to 15 inches; yellowish brown (10YR 5/4) clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky; hard, friable, moderately sticky and moderately plastic; few very fine, fine and medium roots; few very fine and few fine tubular, and common fine interstitial pores; few thin clay films in pores, on faces of peds, and bridging mineral grains, and very few moderately thick clay films in pores and on faces of peds; strongly effervescent, carbonates disseminated, violently effervescent, carbonates segregated as 25 percent fine and medium concretions, threads, and soft masses; calcium carbonate equivalent is 23 percent; electrical conductivity is 0.4 decisiemens per meter; sodium adsorption ratio is 1; 2 percent gravel; moderately alkaline (7.9); abrupt wavy boundary. (1 to 4 inches thick)
2Bkqm--15 to 34 inches; white (10YR 8/1) indurated duripan with 2 millimeter silica laminar caps spaced 5 inches apart, light yellowish brown (10YR 6/4) moist; massive; very rigid; few very fine, fine and medium roots oriented laterally on laminar caps; violently effervescent, carbonates disseminated; calcium carbonate equivalent is 56 percent; clear smooth boundary. (9 to 20 inches thick)
2Bkqym--34 to 60 inches white (10YR 8/1) indurated duripan, light yellowish brown (10YR 6/4) moist; massive, very rigid; few medium roots; violently effervescent, carbonates disseminated; calcium carbonate equivalent is 56 percent; 2 percent gypsum crystals.
TYPE LOCATION: Fresno County, California, 0.75 miles southeast of fork in access road, 3.3 miles east of Mercey Hot Springs, 100 feet west of access road; 2,640 feet north and 600 feet east of the southwest corner of section 20, T. 14 S., R. 11 E, MDB&M; Latitude 36 degrees, 41 minutes, 46 seconds north and Longitude 120 degrees, 47 minutes, 48 seconds west; USGS Mercey Hot Springs Topographic Quadrangle, NAD 27.
RANGE IN CHARACTERISTICS: Depth to an indurated duripan with a very rigid silica capping is 10 to 20 inches. Gravel content on the surface is 1 to 14 percent. Gravel content in the profile is 0 to 10 percent, independent of those on the surface.
The A horizon has color of 10YR 6/3, 6/4; 2.5Y 6/2 or 6/4. Moist color is 10YR 4/3, 4/4, 5/4 or 2.5Y 5/4. Organic matter content is 1 to 2 percent. Clay content is 15 to 25 percent. It is strongly effervescent to violently effervescent but some pedons do not have segregated carbonates. Calcium carbonate equivalent is 5 to 15 percent. Electrical conductivity is 2 to 8 decisiemens per meter. Sodium adsorption ratio is 2 to 8.
The Bt horizon has color of 10YR 4/4, 5/4, 6/3, 6/4, 7/4; 2.5Y 6/4 or 7/2. Moist color is 10YR 4/4, 5/4, 5/6, 6/4, 6/6, 7/4; 2.5Y 4/6, 5/2, 5/6 or 7.5YR 4/4. Organic matter content is 0.5 to 1 percent. Clay content is 20 to 27 percent. Calcium carbonate equivalent is 10 to 20 percent. Electrical conductivity is 0 to 2 decisiemens per meter. Sodium adsorption ratio is 1 to 6.
The Btk horizon has color of 10YR 4/4, 5/4, 6/3, 6/4, 7/4; 2.5Y 6/4 or 7/2. Moist color is 10YR 5/4, 5/6, 6/4, 6/6, 7/4; 2.5Y 4/6, 5/2, 5/6 or 7.5YR 4/4. Organic matter content is 0.2 to 0.6 percent. Clay content is 27 to 35 percent. Calcium carbonate equivalent is 15 to 35 percent. Electrical conductivity is 0 to 2 decisiemens per meter. Sodium adsorption ratio is 1 to 5.
The duripan is 35 to 45 inches thick and is 50 to 90 percent continuous on a flat plane with fractures spaced from 4 to 6 inches apart.
COMPETING SERIES: This is the Igo (T) series. Igo soils (MLRA 17) are on hummocky old terraces formed in gravelly and cobbly alluvium derived largely from andesite, basalt and rhyolite. They have color hue of 5YR or 7.5YR and depth to a duripan is 3 to 12 inches.
GEOGRAPHIC SETTING: Cyvar soils are on erosional fan remnants on mountains. The soils formed in material weathered from calcareous sandstone and shale. Slope is 5 to 15 percent. Elevation is 640 to 2,320 feet. The climate is subhumid with hot, dry summers and cool moist winters. The mean annual precipitation is 9 to 12 inches. Mean January temperature is about 46 degrees F.; mean July temperature is about 81 degrees F.; mean annual temperature is 60 to 63 degrees F. The frost-free season is 230 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Belgarra,
Exclose and
Nodhill soils. Belgarra soils are on erosional fan remnants on mountains and are deep, have a fine particle-size control section, and have a gypsic horizon. Exclose soils are on mountains and are deep, have a cambic horizon, and do not have a duripan. Nodhill soils are on erosional fan remnants on mountains and are moderately deep and do not have a duripan.
DRAINAGE AND PERMEABILITY: Moderately well drained; very high runoff; moderately slow permeability above the duripan and very slow permeability in the duripan.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Some areas have been mined for gypsum. The vegetation is red brome, soft chess, filaree, Ephedra, pine bluegrass, and goldenbrush.
DISTRIBUTION AND EXTENT: These soils are on the eastern edge of the Diablo Range, near the Panoche Hills in the California Coast Ranges. They are not extensive. MLRA-15.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Fresno County, California, 2002.
REMARKS: In the Western part of Fresno County, California, these soils formed in material weathered from calcareous sediment of the Tulare Formation. They are usually underlain by soft sandstones and soft shales of the Panoche Formation at depths greater than 60 inches. These soils were formally mapped as Mercey in the unpublished 1967 report, Soil Survey of Western Fresno Area, California. The Cyvar soils are differentiated by a xeric moisture regime, shallow soil, and a duripan. The calcium carbonate equivalent, sodium adsorption ratio, and electrical conductivity were determined at the Hanford Soil Survey Office Laboratory. Paul Nazar's field clothes were buried in the typical pedon during his retirement celebration on December 21, 1992.
Major diagnostic horizons and features recognized in the pedon are:
1. Ochric epipedon -- 0 to 2 inches (A horizon)
1.1 Dry color values 6 or more and moist values 4 or higher.
2. Argillic Horizon -- 2 to 15 inches (Bt, Btk horizons)
2.1 A horizon: 15 to 25 percent clay, Btk horizon: 27 to 35 percent clay and always having 20 percent more total clay than the above eluvial horizon.
2.2 Argillic horizon has clay films.
2.3 Argillic horizon is 13 inches thick in the typical pedon.
3. Calcic horizon -- 7 to 15 inches (Btk horizon)
4. Duripan layer -- 35 to 45 inches thick (2Bkqm, 2Bkqym horizons)
4.1 Hard silica and calcium carbonate capping material does not slake in water or concentrated muriatic acid after continuous bathing.