LOCATION LOLAK CA+OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, frigid Vertic Halaquepts
TYPICAL PEDON: Lolak silty clay loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 9 inches; light brownish gray (2.5Y 6/2) silty clay loam, very dark grayish brown (2.5Y 3/2) moist; massive; very hard, friable, very sticky and moderately plastic; common very fine roots; common very fine interstitial and tubular pores; strongly effervescent; disseminated carbonates; strongly alkaline (pH 8.6); clear smooth boundary. (2 to 10 inches thick)
A2--9 to 15 inches; light brownish gray (2.5Y 6/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak fine subangular blocky structure: hard, friable, very sticky and moderately plastic; very few very fine roots; common very fine tubular pores and very few very fine interstitial pores; strongly effervescent; disseminated carbonates; strongly alkaline (pH 8.8); abrupt smooth boundary. (1 to 6 inches thick)
C1--15 to 32 inches; light olive gray (5Y 6/2) silty clay, dark grayish brown (2.5Y 4/2) moist; weak fine and medium subangular blocky structure; very hard, firm, moderately sticky and very plastic; very few very fine roots; few very fine tubular pores; common fine prominent bluish gray (5B 5/1) moist iron depletions which change or disappear on exposure to air; strongly effervescent; disseminated carbonates; strongly alkaline (pH 8.6); clear smooth boundary. (4 to 18 inches thick)
C2--32 to 44 inches; light gray (5Y 7/2) silty clay, grayish brown (2.5Y 5/2) moist; massive, very hard, firm, moderately sticky and moderately plastic; very few very fine interstitial pores; strongly effervescent; disseminated carbonates; very strongly alkaline (pH 9.2); abrupt smooth boundary. (3 to 12 inches thick)
2C3--44 to 60 inches; light brownish gray (2.5Y 6/2) sand, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine interstitial pores; violently effervescent; disseminated carbonates; strongly alkaline (pH 8.8).
TYPE LOCATION: Modoc County, California; about 5 miles southwest of the town of Davis Creek; approximately 360 feet east of stock pond, 760 feet north of the east-west dirt road, and 2.7 miles south and west on dirt road from Westside road to stock pond; in the NW 1/4 of the NW 1/4 of section 27, T. 45 N., R. 13 E.; USGS Lauer Reservoir 7.5 minute topographic quadrangle; 41 degrees 43 minutes 03 seconds north latitude and 120 degrees 27 minutes 58 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually saturated in the spring at depths within 20 inches during most years; Seasonal periods of aquic moisture regime.
Mean annual soil temperature - 42 to 47 degrees F.
Particle-size control section - Clay content: Averages 35 to 50 percent.
Reaction - Strongly alkaline to very strongly alkaline.
Exchangeable sodium - About 30 percent in the upper 20 inches (SAR of 13 to 40) and decreases with increasing depth.
Effervescence- strong to violent.
Redoximorphic features - Redox depletions occur as few or common, and range from fine to coarse; zones of iron depletion or masses of iron accumulation are at depths of less than 36 inches and often are as high as 6 inches are in some pedons.
Linear extensibility (LE) - 6 to 9 cm.
A horizons
Hue: 10YR thru 5Y.
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 1 or 2, dry or moist.
Structure: Weak or moderate very thin to medium platy, granular, blocky or massive.
C horizons
Hue: 10YR thru 5Y.
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 1 or 2, dry or moist.
Texture: Silty clay, clay, or silty clay loam.
Consistence: Very hard or extremely hard dry, firm to very firm moist.
Other features: Thin (6 inches) strata of silty clay loam, silt loam, or fine sand are in some pedons; within the particle-size control section fine sand occurs only in 1 inch thick strata; horizons of strongly contrasting sandy texture are below 40 inches in some pedons.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Lolak soils are on basin floors and lake plains. They formed in lacustrine deposits derived from volcanic rocks such as tuff, andesite, basalt, and volcanic ash. Slopes are 0 to 2 percent. Elevations range from 4,000 to 4,700 feet. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 8 to 15 inches, the mean annual temperature is 41 to 46 degrees F. The mean January temperature is about 24 degrees F. and the mean July temperature about 64 degrees F. The frost-free period is 50 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bicondoa, Cuminvar, and Tandy soils. Bicondoa soils have darker surface colors. Cuminvar soils have 8 to 16 inch thick organic surface. Tandy soils have sandy over loamy control sections.
DRAINAGE AND PERMEABILITY: Poorly drained; negligible or very high surface runoff depending on ponding; very slow permeability (low or moderately low saturated hydraulic conductivity). Endosaturation is present with an apparent seasonal high water table between the soil surface and 2 feet (very shallow to moderately deep free water occurrence classes) between March and July. Cumulative annual duration class is Common. The saturation fluctuates with the level of water in adjacent lakes or playas. It is highest during spring runoff and drops to about 6 feet in the fall. Some phases are susceptible to rare flooding for brief periods year-round. Some phases are susceptible to frequent ponding for long duration from March through May with water up to one foot deep.
USE AND VEGETATION: Lolak soils are used to provide livestock grazing and wildlife habitat. Vegetation is sparse in the high-lying areas and is mainly black greasewood, suaeda, and some inland saltgrass. It is fairly dense in the lower-lying areas and consists of inland saltgrass and rush.
DISTRIBUTION AND EXTENT: Northeastern California and south-central Oregon. These soils are moderately extensive. The series concept and main acreage is in MLRA 23, while other acreage occurs in MLRA 21.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Surprise Valley-Home Camp Area, California and Nevada, 1971. The type location was moved from Washoe County, Nevada to Modoc County, California in April 2006 to better reflect the series concept.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 15 inches (A1 and A2 horizons).
Aquic conditions - The conditions of endosaturation, reduction, and redoximorphic features between the soil surface and 60 inches at certain times during normal years.
Particle-size control section - The zone from 10 to 40 inches(part of A2, C1 and part of C2).
The Vertic subgroup placement is based on the estimated linear extensibility (LE) as populated in the NASIS database.