LOCATION BOULDER LAKE NV+CA ID OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Xeric Epiaquerts
TYPICAL PEDON: Boulder Lake clay--rangeland. (Colors are for moist soil unless otherwise noted.)
A--0 to 2 inches; very dark grayish brown (10YR 3/2) clay, grayish brown (10YR 5/2) dry; strong very fine and fine granular structure; slightly hard, friable, very sticky and very plastic; root crowns only; many very fine and fine interstitial pores; slightly acid (pH 6.4); abrupt smooth boundary. (1/4 to 8 inches thick)
Bw--2 to 4 inches; dark grayish brown (10YR 4/2) clay, grayish brown (10YR 5/2) dry; moderate medium prismatic structure; slightly hard, friable, very sticky and very plastic; few very fine, fine and medium roots; many very fine and fine interstitial pores; neutral (pH 6.6); abrupt wavy boundary. (0 to 5 inches thick)
Bss1--4 to 6 inches; dark grayish brown (10YR 4/2) clay, grayish brown (10YR 5/2) dry; moderate coarse prismatic structure and strong very fine and fine angular blocky; slightly hard, friable, very sticky and very plastic; many very fine, few fine and medium roots; few very fine and fine tubular, and many very fine and fine interstitial pores; few slickensides; neutral (pH 6.6); clear wavy boundary. (2 to 20 inches thick)
Bss2--6 to 24 inches; dark grayish brown (10YR 4/2) clay, light brownish gray (10YR 6/2) dry; moderate medium prismatic structure; very hard, firm, very sticky and very plastic; few very fine, fine and medium roots; few fine tubular, and many very fine interstitial pores; common slickensides; few fine and medium distinct brown (7.5YR 4/4) and very dark brown (7.5YR 2.5/2) masses of iron and manganese accumulation; neutral (pH 6.8); gradual smooth boundary. (12 to 30 inches thick)
Bss3--24 to 62 inches; dark grayish brown (10YR 4/2) clay, light brownish gray (10YR 6/2) dry; weak coarse prismatic structure and strong medium through very coarse angular blocky; very hard, firm, very sticky and very plastic; few fine and medium roots; few fine tubular, and many very fine interstitial pores; common slickensides; common fine distinct brown (7.5YR 4/4) and dark brown (7.5YR 3/4) masses of iron accumulation; few fine and medium faint very dark brown (10YR 2/2) masses of manganese accumulation; neutral (pH 6.8).
TYPE LOCATION: Washoe County, Nevada; about 0.75 miles west of Boulder Lake; near the center of section 9, T. 40 N., R. 19 E.; USGS Boulder Lake 7.5 minute topographic quadrangle; 41 degrees 23 minutes 44 seconds north latitude and 119 degrees 51 minutes 33 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually ponded for less than 45 consecutive days in most years, mainly in the spring; brief ponding occurs after intensive rainfall. Saturated to a depth of 30 to 60 inches in late winter and spring; Seasonal periods of aquic moisture regime when the soil moisture control section is saturated and reduced.
Mean annual soil temperature - 43 to 47 degrees F.
Mean summer soil temperature - 62 to 64 degrees F.
Effervescence- Noneffervescent or slightly effervescent but ranges to strongly effervescent in some pedons where few to common, very fine to medium filaments or masses of carbonate occur below depths of 20 inches.
Particle-size control section - Clay content: Averages 40 to 60 percent.
Other features - Reversible trans-horizon cracks are normally open to the soil surface during summer and early fall, are up to 3 inches wide, and are 3 to 6 inches apart. They decrease in width with increasing depth. Cracks remain open for fewer than 180 consecutive days.
A horizon - Hue: 10YR or 2.5Y.
Value: 3 through 5 moist, 5 or 6 dry.
Chroma: 2 or 3 moist, 1 through 3 dry.
Reaction: Slightly acid through slightly alkaline.
Bw horizon (when present) and Bss horizons - Hue: 10YR through 5Y.
Chroma: 2 or 3, moist or dry; Some pedons have dry chroma of 1 in the Bss1 horizon; dominantly chroma 2 or less above 20 inches.
Texture: Clay or silty clay.
Structure: Moderate or strong, very fine to very coarse prismatic, medium to very coarse angular blocky in the upper part and weak to strong, medium to very coarse prismatic and moderate or strong, medium to very coarse angular in the lower subhorizons.
Consistence: Very hard or extremely hard, dry; firm or very firm, moist; may be slightly hard and friable in the upper subhorizon.
Redoximorphic features: Few or common, very fine to medium, distinct or prominent, redox concentrations of iron and manganese with reddish, yellowish and brownish colors that have hue of 10YR through 5YR and chroma of 2 through 6.
Reaction: Neutral through moderately alkaline.
Vertic features: Few to many slickensides and many pressure cutans. Soil is interpreted as having reduced matrix colors and redox concentrations due to saturation.
Bk horizon (when present) - Hue: 10YR through 5Y.
Value: 5 through 7, moist or dry.
Chroma 2 through 6, moist or dry.
Texture: Silty clay loam or clay loam.
Clay content: 35 to 40 percent.
Reaction: Slightly alkaline or moderately alkaline.
COMPETING SERIES: This is the Chancelakes (T) series. Chancelakes soils have albic horizons, argillic horizons, and ashy surface textures.
GEOGRAPHIC SETTING: Boulder Lake soils are on depressions on plateaus and on lake plains. These soils formed in lacustrine deposits derived mainly from volcanic rocks such as tuff, basalt, and andesite. Gilgai microrelief is evident in most areas. Slopes are 0 to 2 percent. Elevations range from 4,500 to 7,200 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 9 to 20 inches, the mean annual temperature is 41 to 47 degrees F., and the frost-free period is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Disabel and Schamp soils. Disabel and Schamp soils have clayey argillic horizons and are well drained.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; negligible through very high surface runoff; very slow permeability. These soils are susceptible to occasional or frequent ponding for long duration from December through June with water up to two feet deep. Some areas are also susceptible to rare ponding for brief or very brief duration during summer and fall months. Ponding is a result of surface runoff from higher-lying soils and is less than 45 consecutive days in most years.
USE AND VEGETATION: Boulder Lake soils are used for livestock grazing and wildlife habitat. The vegetation is mainly silver sagebrush, Nevada bluegrass, mat muhly, poverty weed, and primrose, with some Carex and Rumex species.
DISTRIBUTION AND EXTENT: Northern Nevada, northeastern California, south-central Oregon, and southwestern Idaho. These soils are moderately extensive. The series concept and main acreage is in MLRA 23, while other acreage occurs in MLRAs 21 and 25.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Washoe County (Surprise Valley-Home Camp Area), Nevada, 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 2 inches (A horizon).
Slickensides- The zone from 4 to 60 inches (Bss1, Bss2, and Bss3 horizons).
Particle-size control section - The zone from 10 to 40 inches (parts of the Bss2 and Bss3 horizons).