LOCATION DANGVAR CAEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Aquic Natrargidic Natridurids
TYPICAL PEDON: Dangvar ashy loam--Rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; light brownish gray (10YR 6/2) ashy loam, dark grayish brown (10YR 4/2) moist; moderate medium platy structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; many very fine tubular and interstitial pores; strongly effervescent; very strongly alkaline (pH 9.2) abrupt smooth boundary (1 to 2 inches thick)
A2-- 2 to 4 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; few very fine tubular pores and many very fine interstitial pores; strongly effervescent; very strongly alkaline (pH 9.3) abrupt wavy boundary (2 to 4 inches thick)
Btn--4 to 9 inches; light brownish gray (10YR 6/2) silty clay, dark grayish brown (10YR 4/2) moist; moderate fine and medium columnar structure; very hard, firm, very sticky and very plastic; common very fine exped and few very fine inped roots; common very fine tubular pores; common faint clay films lining pores and many pressure cutans; strongly effervescent; very strongly alkaline (pH 9.4) clear wavy boundary (4 to 7 inches thick)
Btkn--9 to 17 inches; light brownish gray (10YR 6/2) silty clay, dark grayish brown (10YR 4/2) moist; strong medium prismatic structure; very hard, firm, very sticky and very plastic; common very fine exped and few very fine inped roots; many very fine tubular pores; many faint clay films lining pores and many pressure cutans; many fine to coarse white (10YR 8/1) soft lime masses in lower part; strongly effervescent; very strongly alkaline (pH 9.2) abrupt smooth boundary. (4 to 15 inches thick)
Bkqm--17 to 20 inches; variegated light gray (10YR 7/2) and light brownish gray (10YR 6/2) strongly cemented duripan, dark grayish brown (10YR 4/2) and light brownish gray (10YR 6/2) moist; moderate medium and thick platy structure; extremely hard and extremely firm in upper part and very hard and very firm in lower part; common very fine roots matted on upper surface; common very fine tubular pores and many very fine interstitial pores; many thin silica films lining pores and bridging sand grains; common very thin discontinuous silica laminar cap on upper surface; many very pale brown (10YR 8/2) lime coatings on ped faces; violently effervescent; very strongly alkaline (pH 9.1) clear wavy boundary (1 to 5 inches thick)
Bkq1--20 to 35 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; massive; very hard, firm, slightly sticky and slightly plastic; few very fine roots; many very fine and few fine tubular pores; many very thin silica coats lining pores and bridging sand grains, very thin discontinuous silica lanminae and 40 percent fine to coarse moderately cemented silica durinodes; common fine to coarse white (10YR 8/1) soft lime filaments; few fine faint brown (10YR 5/3) redox concentrations; violently effervescent; very strongly alkaline (pH 9.2) gradual wavy boundary. (8 to 20 inches thick)
Bkq2--35 to 60 inches; variegated light gray (10YR 7/2) and light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, sticky and plastic; few very fine roots; common very fine and fine tubular pores; 25 percent medium and coarse weakly cemented silica durinodes; common fine and medium very pale brown (10YR 8/2) soft lime filaments; few very fine distinct very dark grayish brown (10YR 3/2) and very dark brown (10YR 2/2) iron manganese redox concentrations; violently effervescent; strongly alkaline (pH 9.0).
TYPE LOCATION: Modoc County, California; in Surprise Valley, east of the Warner Mountains, about 5 miles northeast of Cedarville ; about 200 feet south and 300 feet west of the northeast corner of section 17, T. 43 N., R.16 E.; Cedarville USGS 7.5 minute topographic quadrangle; 41 degrees 36 minutes 08 seconds north latitude and 120 degrees 09 minutes 44 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry, moist for short periods in winter and spring, dry from summer to mid-fall; typic aridic moisture regime.
Mean annual soil temperature - 47 to 50 degrees F.
Depth to duripan - 14 to 20 inches.
Control section - Clay content: Averages 40 to 60 percent; Rock fragments: Averages less than 5 percent
A horizons - Hue: 10YR or 2.5Y.
Value: 5, 6 or 7 dry, 3 or 4 moist.
Chroma: 1 or 2 dry or moist.
Structure: Weak or moderate, thin to thick platy, or is massive.
Volcanic glass content - 30 to 50 percent glass and glass aggregates in the coarse silt to sand fraction.
Salinity (EC): 4 to 32 mmhos/cm.
Sodicity (SAR): 13 to 90.
Reaction: Strongly alkaline or very strongly alkaline.
Btn Horizon - Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3 dry or moist.
Texture: Clay or silty clay.
Structure: Moderate or strong fine to coarse columnar structure.
Clay content: 40 to 60 percent.
Rock fragments: Less than 5 percent.
Salinity (EC): 8 to 32 mmhos/cm.
Sodicity (SAR): 31 to 90.
Reaction: Strongly or very strongly alkaline.
Btkn Horizon - Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3 dry or moist.
Texture: Clay or silty clay.
Structure: Moderate or strong fine to coarse columnar structure.
Clay content: 40 to 60 percent.
Rock fragments: Less than 5 percent
Salinity (EC): 8 to 32 mmhos/cm.
Sodicity (SAR): 31 to 90.
Carbonates: Common or many fine to coarse soft lime masses.
Calcium carbonate equivalent: 5 to 10 percent.
Effervescence: Strongly effervescent or very strongly effervescent in the matrix.
Reaction: Strongly or very strongly alkaline.
Bqkm horizon - Structure: Commonly is platy, but is massive in some pedons or in subhorizons of some pedons.
Bkq1 horizon - Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3 dry or moist.
Texture: Loam.
Clay content: 20 to 27 percent.
Rock fragments: Less than 5 percent.
Salinity (EC): 4 to 32 mmhos/cm.
Sodicity (SAR): 13 to 90.
Redoximorphic features: Redox concentrations occur as
masses of iron and manganese accumulation.
Durinodes: 20 to 50 percent weak to moderately cemented durinodes or silica laminae.
Carbonates: Common or many fine to coarse soft lime masses.
Calcium carbonate equivalent: 5 to 10 percent.
Effervescence: Strongly effervescent or very strongly effervescent in the matrix.
Reaction: Strongly or very strongly alkaline.
Bkq2 horizon - Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3 dry or moist.
Texture: Silty clay loam.
Clay content: 27 to 35 percent.
Rock fragments: Less than 5 percent.
Salinity (EC): 4 to 32 mmhos/cm.
Sodicity (SAR): 13 to 90.
Redoximorphic features: Redox concentrations occur as
masses of iron and manganese accumulation.
Durinodes: 20 to 50 percent weak to moderately cemented durinodes or silica laminae.
Carbonates: Common or many fine to coarse soft lime masses.
Calcium carbonate equivalent: 5 to 10 percent.
Effervescence: Strongly effervescent or very strongly effervescent in the matrix.
Reaction: Strongly or very strongly alkaline.
COMPETING SERIES: This is the Dangberg series. Dangberg soils do not have a 30 to 50 percent volcanic glass in the upper part of their profile.
GEOGRAPHIC SETTING: Dangvar soils are on lake terraces. They formed in lacustrine sediments derived from mixed volcanic rocks with additions of volcanic ash. Slopes are 0 to 5 percent. Elevations range from 4,400 to 4,600 feet. The climate is semi-arid with cool, moist winters and warm, dry summers. The mean annual precipitation is 9 to 12 inches, mean annual temperature is 44 to 45 degrees F., and the frost-free period is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hussa and Raglan series. Hussa soils have a mollic epipedon. Raglan soils lack a natric horizon.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; Endosaturation is present with a seasonal high water table between 1.5 and 3.0 feet (shallow and moderately deep free water occurrence classes) between December and May. Cumulative annual duration class is Common. The drainage in some areas has been altered due to the presence of gullies. These soils are susceptible to rare flooding for very brief periods year-round; high surface runoff; very slow permeability.
USE AND VEGETATION: Dangvar soils are used for rangeland, watershed and wildlife habitat. The native vegetation is mainly inland saltgrass and black greasewood.
DISTRIBUTION AND EXTENT: Eastern California, east of the Warner Mountains, in Surprise Valley. These soils are not extensive. MLRA 23.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Modoc County (Surprise Valley Home Camp Area), California, 2006.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 4 inches (A1 and A2 horizons).
Natric horizon - The zone from 4 to 17 inches (Btn and Btkn horizons).
Identifiable secondary carbonates - The zone from 9 to 60 inches (Btkn, Bkqm, Bkq1, and Bkq2 horizons).
Endosaturation feature - The condition of ground water with an upper boundary between 18 and 36 inches at certain times during normal years (parts of the Bkq1 and Bkq2 horizons).
Duripan - The zone from 17 to 20 inches (Bqkm horizon).
Particle-size control section - The zone from 4 to 17 inches (Btn and Btkn horizon).