LOCATION THUNDEREGG OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Natraquolls
TYPICAL PEDON: Thunderegg fine sandy loam--native wet meadow hayland and pasture. (Colors are for moist soil unless otherwise noted.)
A--0 to 1 inch; very dark gray (10YR 3/1) fine sandy loam, gray (10YR 5/1) dry; weak thin platy structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine discontinuous tubular pores; moderately alkaline (pH 8.0); clear smooth boundary. (1 to 4 inches thick)
Ak--1 to 8 inches; very dark gray (10YR 3/1) fine sandy loam, gray (10YR 5/1) dry; single grain; loose, nonsticky and nonplastic; common very fine and fine roots; strongly effervescent; strongly alkaline (pH 8.8); abrupt smooth boundary. (5 to 10 inches thick)
2Btkn1--8 to 15 inches; dark grayish brown (10YR 4/2) exterior, silty clay loam, pale brown (10YR 6/3) exterior dry; moderate medium and coarse prismatic structure; hard, very firm, slightly sticky and slightly plastic; common very fine and fine roots; few very fine and fine tubular pores; many faint dark grayish brown (10YR 4/2) clay films on faces of peds; violently effervescent; very strongly alkaline (pH 9.6); clear wavy boundary. (7 to 12 inches thick)
2Btkn2--15 to 21 inches; 60 percent brown (10YR 4/3) and 40 percent dark yellowish brown (10YR 4/4) silty clay loam, 60 percent pale brown (10YR 6/3), and 40 percent grayish brown (10YR 5/2) dry; weak fine and medium prismatic structure; hard, very firm, slightly sticky and slightly plastic; common very fine and fine roots; few very fine and fine tubular pores; many faint dark yellowish brown (10YR 4/4) clay films on faces of peds; violently effervescent; very strongly alkaline (pH 9.6); abrupt wavy boundary. (6 to 12 inches thick)
2Btknq--21 to 26 inches; 60 percent yellowish brown (10YR 5/4) and 40 percent light yellowish brown (10YR 6/4) loam, pale brown (10YR 6/3) dry; massive; very hard, extremely firm, slightly sticky and slightly plastic; few fine roots; common fine and medium vesicular and tubular pores; common distinct dark yellowish brown (10YR 4/4) clay films on fracture planes; 10 percent cylindrical and rounded silica and manganese nodules; secondary carbonates segregated as few fine threads and few fine and medium rounded masses; violently effervescent; very strongly alkaline (pH 9.6); clear wavy boundary. (4 to 12 inches thick)
3Bkn--26 to 31 inches; brown (10YR 4/3) sand, very pale brown (10YR 7/3) dry; single grain; loose, nonsticky and nonplastic; many medium and coarse distinct dark yellowish brown (10YR 4/6) masses of iron accumulation and common fine and medium distinct black (10YR 2/1) masses of manganese accumulation; secondary carbonates segregated as few fine threads and common medium and coarse irregular masses; strongly effervescent; very strongly alkaline (pH 9.6); abrupt smooth boundary. (4 to 10 inches thick)
3Bz--31 to 70 inches; brown (10YR 4/3) sand, light brownish gray (10YR 6/2) dry; single grain; loose, nonsticky and nonplastic; upon drying soluble salts wicked to the exposed surface; many medium and coarse distinct dark yellowish brown (10YR 4/6) masses of iron accumulation and common fine and medium distinct black (10YR 2/1) masses of manganese accumulation; strongly alkaline (pH 8.8).
TYPE LOCATION: Lake County, Oregon; in Goose Lake Valley about 2.5 miles north of Goose Lake; about 900 feet south and 400 feet west of the northeast corner of section 9, T. 40 S., R. 20 E.; USGS Crane Creek 7.5 minute topographic quadrangle; 42 degrees 07 minutes 07 seconds north latitude and 120 degrees 21 minutes 26 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil is ponded in spring and has a water table in the sandy layers throughout the year.
Mean annual soil temperature - 48 to 50 degrees F.
Mollic epipedon thickness - 8 to 18 inches; includes the upper part of the natric horizon in some pedons.
Depth to sandy horizons - 25 to 50 inches.
Particle-size control section - Clay content: Averages 35 to 45 percent.
A horizons - Value: 2 or 3 moist, 4 or 5 dry.
Chroma: 1 or less, moist or dry.
2Btkn horizons - Hue: 10YR or 2.5Y.
Value: 3 through 6 moist, 5 or 6 dry.
Chroma: 2 through 4, moist or dry.
Texture: Silty clay loam, silty clay, or clay in the upper part and loam or clay loam in the lower part.
Clay content: 35 to 45 percent in the upper part and 25 to 40 percent in the lower part.
Reaction: Strongly alkaline or very strongly alkaline.
Sodicity (SAR): 15 to 40.
Other features: Contains hard, firm and brittle silica nodules in the lower part.
3Bkn horizon - Value: 4 or 5 moist, 6 or 7 dry.
Chroma: 2 through 4, moist or dry.
3Bz horizon - Value: 4 or 5 moist, 6 or 7 dry.
Chroma: 2 through 4, moist or dry.
Texture: Stratified sand and gravel.
Rock fragments: 0 to 70 percent gravel.
Other features: This horizon is typically saturated throughout the year and contains dissolved salts; Some pedons have silty clay loam or sandy clay loam below the sandy layers.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Thunderegg soils are on low lake terraces. These soils formed in eolian material over lacustrine deposits derived from volcanic rocks. The eolian material may be influenced by volcanic ash. Slopes are 0 to 1 percent. Elevations range from 4,710 to 4,760 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 14 to 18 inches, the mean annual temperature is 45 to 49 degrees F., and the frost-free period is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Goose Lake, Lakeview, Stockdrive, and Tandy soils. Goose Lake, Lakeview, and Tandy soils do not have a natric horizon. Tandy and Stockdrive soils are somewhat poorly drained. Lakeview soils are moderately well drained.
DRAINAGE AND PERMEABILITY: Poorly drained; high surface runoff; slow permeability. A high water table ranges from one half foot above the surface to 4.0 feet below the surface from January to December; Ponding occurs in the spring from snowmelt (March to May). A water table is within 2 to 4 feet throughout the year.
USE AND VEGETATION: Thunderegg soils are used for native wet meadow hay and pasture, and wetland wildlife habitat. Native vegetation is tufted hairgrass, Baltic rush, northern mannagrass, and Nebraska sedge.
DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 9,200 acres of the series mapped to date. MLRA 21.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Lake County, Oregon, Southern Part, 1991.
REMARKS: This series is marginal to a strongly contrasting particle-size class of clayey over sandy or sandy-skeletal. The 2Btknq horizon is not considered to be part of the natric horizon and is too thick to allow the typical pedon to qualify for a strongly contrasting class. Future study is needed to determine the amount of volcanic glass influence in the A and Ak horizons.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 8 inches (A and Ak horizons).
Aquic conditions - The conditions of endosaturation, reduction, and redoximorphic features between the soil surface and 60 inches at certain times during normal years.
Natric horizon - The zone from 8 to 21 inches (2Btkn1 and 2Btkn2 horizons).
Identifiable secondary carbonates - The zone from 21 to 31 inches (2Btknq and 3Bkn horizons).
Particle-size control section - The zone from 8 to 21 inches (2Btkn1 and 2Btkn2 horizons).