LOCATION SURPRISE                CA+NV

Established Series
Rev. JBF/TM/JVC
12/2011

SURPRISE SERIES

The Surprise series consists of very deep, well drained soils that formed in alluvium derived from tuff and tuff-breccia. Surprise soils are on fan skirts, inset fans, and fan remnants. Slopes are 0 to 15 percent. The mean annual precipitation is about 330 mm and the mean annual temperature is about 10 degrees C.

TAXONOMIC CLASS: Ashy, glassy, mesic Vitritorrandic Haploxerolls

TYPICAL PEDON: Surprise gravelly ashy sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 8 cm; grayish brown (10YR 5/2) gravelly ashy sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; soft, very friable; many fine roots; many very fine pores; 30 percent gravel; neutral (pH 6.8); clear smooth boundary. (8 to 15 cm thick)

A2--8 to 23 cm; grayish brown (10YR 5/2) gravelly ashy sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable; many fine roots; many very fine pores; 25 percent gravel; neutral (pH 6.8); gradual smooth boundary. (13 to 20 cm thick)

Bw--23 to 71 cm; light brownish gray (10YR 6/2) gravelly ashy sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable; many fine roots; many fine pores; 25 percent gravel; neutral (pH 6.8); gradual smooth boundary. (38 to 76 cm thick)

C1--71 to 114 cm; light brownish gray (10YR 6/2) gravelly ashy sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable; common fine and few medium roots; many fine pores; 25 percent gravel; neutral (pH 6.8); gradual wavy boundary. (20 to 38 cm thick)

C2--114 to 170 cm; light brownish gray (10YR 6/2) very gravelly ashy sandy loam, dark grayish brown (10YR 4/2) moist; massive; soft, very friable; few fine and common medium roots; many fine pores; 35 percent gravel and 3 percent cobbles; neutral (pH 6.8).

TYPE LOCATION: Modoc County, California; in Surprise Valley about 2 miles north of Eagleville; approximately 250 feet south and 1,740 feet west of the northeast corner of section 14, T. 40 N., R. 16 E.; USGS Eagleville 7.5 minute topographic quadrangle; latitude 41 degrees 20 minutes 22 seconds N and longitude 120 degrees 07 minutes 28 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in winter and spring, dry throughout the summer and fall; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 9 to 12 degrees C.
Mollic epipedon thickness: 20 to 43 cm.
Depth to base of cambic horizon: 61 to 122 cm.
Reaction: Slightly acid or neutral.
Volcanic glass content: 30 to 60 percent in the coarse silt through fine sand fractions.

Particle-size control section - Clay content: Averages 10 to 18 percent.
Rock fragments: Averages 15 to 35 percent, mainly gravel. Lithology of fragments are volcanic rocks such as tuff and tuff-breccia.

A horizons
Value: 4 or 5 dry.
Chroma: 2 or 3, dry or moist.
Structure: Weak to moderate, fine to medium, platy, granular or subangular blocky, or is massive.
Consistence: Soft or slightly hard, dry.

Bw horizon
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Predominantly gravelly ashy sandy loam; individual strata range from gravelly ashy sandy loam to ashy loam.
Clay content: 10 to 18 percent.
Rock fragments: 15 to 35 percent; any one stratum ranges from 0 to 50 percent.
Structure: Massive or has weak, medium or coarse subangular blocky structure.

C horizons
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 7 to 12 percent; contains less clay than the Bw horizons in each pedon.
Rock fragments: Averages 25 to 50 percent, mainly gravel.

COMPETING SERIES: These are the Bitner, Brays, Chelan, Deskamp, Dryhollow, Emagert, Kester, Weezweed, Winblow, Yellowhills, Yotes, and Zark series.

Bitner soils have soft bedrock between 50 and 100 cm. Brays soils are 50 to 100 cm deep over granitic bedrock. Chelan soils have duripans within 100 to 150 cm of the soil surface. Deskamp soils are 50 and 100 cm deep over basalt bedrock. Dryhollow soils have gravel-size fragments that are dominantly pumice. Emagert soils have 18 to 27 percent clay in the control section and mollic epipedon is 61 to 122 cm thick. Kester soils are 50 to 100 cm deep over basalt bedrock. Weezweed soils have 18 to 27 percent clay in the control section and organic matter decreases irregularly with depth. Winblow soils are 50 to 100 cm deep over basalt bedrock. Yellowhills soils have 0 to 15 percent gravel and have Bq horizons with durinodes. Yotes soils have durinodes and secondary carbonates. Zark soils are 50 to 100 cm deep over soft tuff bedrock and have brittle Bq and Bqk horizons.

GEOGRAPHIC SETTING: Surprise soils are on fan skirts, inset fans, and fan remnants. These soils formed in alluvium derived mainly from tuff and tuff-breccia. Slopes are 0 to 15 percent. Elevations range from 1,220 to 1,710 meters. The climate is cool and continental. The mean annual precipitation is 250 to 460 mm, the mean annual temperature is 7 to 11 degrees C, and the frost-free period is 90 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bidwell, Buntingville, Donica and Simpson soils. Bidwell soils have argillic horizons. Buntingville soils are somewhat poorly drained and have argillic horizons. Donica soils have ashy-skeletal control sections. Simpson soils have argillic horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very low or low surface runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Surprise soils are used for irrigated cropland, livestock grazing, and wildlife habitat. Alfalfa in rotation with small grains, and improved pasture are the major uses on irrigated land. The native vegetation is dominantly big sagebrush, antelope bitterbrush, and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Northeastern California and northwestern Nevada. These soils are moderately extensive. MLRA 23.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Modoc County, California (Alturas Area), 1931.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 23 cm (A1 and A2 horizons).
Cambic horizon - The zone from 23 to 71 cm (Bw horizon).
Vitrandic intergrade feature - The zone from the soil surface to 75 cm (A1, A2, Bw and part of the C1 horizons).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 25 to 100 cm (parts of the Bw and C1 horizons).

This soil is reclassified in 2006 based on optical grain count of associated soils and updated to current Soil Taxonomy. The previous classification was coarse-loamy, mixed, superactive, mesic Aridic Haploxerolls.

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National Cooperative Soil Survey
U.S.A.