LOCATION NOWACK CAEstablished Series
TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid Alfic Humic Vitrixerands
TYPICAL PEDON: Nowack very gravelly ashy loam--forestland. (Colors are for dry soil unless otherwise noted).
Oe--0 to 1 inch; dark grayish brown (10YR 4/2) crushed gravelly moderately decomposed organic matter, very dark brown (10YR 2/2) crushed moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; common very fine roots; many very fine interstitial pores; 15 percent pebbles; slightly acid, (pH 6.1); clear smooth boundary. (1 to 3 inches thick)
A--1 to 10 inches; dark grayish brown (10YR 4/2) crushed very gravelly ashy loam, very dark brown (10YR 2/2) crushed moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; many very fine and fine roots and common medium and coarse roots; many very fine interstitial pores; 5 percent cobbles and 35 percent pebbles; slightly acid, (pH 6.1); clear wavy boundary. (5 to 12 inches thick)
Bt1--10 to 18 inches; brown (10YR 5/3) crushed very gravelly ashy loam, dark brown (10YR 3/3) crushed moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky, nonplastic; many very fine and fine roots and common medium and coarse roots; common very fine interstitial and tubular pores; 10 percent faint clay bridges between sand grains; 10 percent paragravel, 10 percent cobbles and 35 percent pebbles; slightly acid, (pH 6.1); clear wavy boundary. (6 to 10 inches thick)
Bt2--18 to 30 inches; yellowish brown (10YR 5/4) crushed very gravelly ashy loam, dark yellowish brown (10YR 3/4) crushed moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; common very fine to coarse roots; common very fine interstitial and tubular pores; 30 percent faint clay bridges between sand grains; 10 percent cobbles, 10 percent paragravel and 45 percent pebbles; slightly acid, (pH 6.1); clear wavy boundary. (8 to 15 inches thick)
Bt3--30 to 42 inches; dark yellowish brown (10YR 4/4) crushed extremely gravelly ashy loam, dark yellowish brown (10YR 3/4) crushed moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; common very fine to coarse roots; common very fine interstitial and tubular pores; 30 percent faint clay bridges between sand grains; 15 percent cobbles, 20 percent paragravel and 45 percent pebbles; moderately acid, (pH 6.0); clear irregular boundary. (0 to 20 inches thick)
Cr--42 to 50 inches; weathered tuff-breccia.
TYPE LOCATION: Modoc County, California; on the Modoc National Forest in the Warner Mountains; 2,100 feet north and 1,100 feet west of the southeast corner of section 21, T 47N, R 15E; Willow Ranch USGS 7.5 minute topographic quadrangle; 41 degrees 55 minutes 38.4 seconds north latitude and 120 degrees 15 minutes 12.5 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - These soils are usually moist in winter, spring, and early summer, dry later in summer and fall; xeric soil moisture regime.
Mean annual soil temperature - 41 to 45 degrees F.
Mean summer soil temperature - 47 to 54 degrees F.
Oxalate extractable Al + 1/2 Fe: 0.4 to 1 percent.
Volcanic glass content - 50 to 80 percent in the coarse silt through fine sand fractions.
Umbric epipedon thickness - 14 to 20 inches.
Depth to bedrock - 40 to 60 inches to a paralithic contact. The paralithic materials below the contact are weathered pyroclastic andesite, andesitic tuff or tuff-breccia.
Profile reaction - Moderately acid or slightly acid.
Particle-size control section - Clay content: Averages 18 to 27 percent, (field estimates).
Rock fragments: Average 35 to 60 percent, mainly gravel or cobbles.
A horizon - Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Rock fragments: Averages 35 to 60 percent, mainly gravel or cobbles.
Organic matter content: 1 to 4 percent.
Bt horizon - Hue: 10YR or 7.5YR.
Texture: Ashy loam or ashy sandy clay loam.
Clay content: 18 to 27 percent.
Rock fragments: Averages 35 to 60 percent, some subhorizons have more than 60 percent rock fragments in the lower part.
Structure: Moderate or strong, fine to coarse subangular blocky.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Nowack soils are on mountains. They formed in volcanic ash and colluvium over residuum derived from andesite, tuff-breccia or andesitic tuff. Slopes are 4 to 50 percent. Elevations range from 5,130 to 8,450 feet. The climate is subhumid with cold, moist winters and warm, dry summers. The mean annual precipitation is 20 to 40 inches, most of which comes as snow. The mean annual temperature is 38 to 44 degrees F. The frost-free period is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Lyonman and Paynepeak series. Lyonman soils have bedrock within 20 to 40 inches. Paynepeak soils have a mollic epipedon and cryic soil temperature regime.
DRAINAGE AND PERMEABILITY: Well drained; medium or high surface runoff; moderate permeability.
USE AND VEGETATION: Nowack soils are used for timber production, watershed, wildlife habitat, and limited livestock grazing. The vegetation consists of a closed forest canopy of white fir with an understory of perennial forbs, bluegrass, sedge and currant.
DISTRIBUTION AND EXTENT: Northeastern California. These soils are not extensive. MLRA 21.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Surprise Valley-Home Camp Area, California and Nevada, 2005.
REMARKS: The name is coined
Diagnostic horizons and features recognized in this pedon include:
Umbric epipedon - The zone from the mineral soil surface to 18 inches (A and the Bt1 horizons).
Andic soil properties - The soil material with high volcanic glass content and acid oxalate extractable Al and Fe more than 0.4 extends from the mineral surface to 42 inches (A, Bt1, and the Bt2 horizons).
Argillic horizon - The zone from 10 to 42 inches (Bt1 and Bt2 horizons).
Paralithic contact - The boundary at 42 inches to underlying soft, weathered bedrock (Cr layer).
Particle-size control section - The zone from 10 to 30 inches (Bt1 and Bt2 horizons).