LOCATION GURLIDAWG CA OREstablished Series
TAXONOMIC CLASS: Ashy-skeletal, glassy Xeric Vitricryands
TYPICAL PEDON: Gurlidawg very gravelly ashy sandy loam--forestland. (Colors are for dry soil unless otherwise noted).
Oe--0 to 1 inch; dark grayish brown (10YR 4/2) crushed very gravelly moderately decomposed organic matter, very dark brown (10YR 2/2) crushed moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; many very fine roots; many very fine interstitial pores; 35 percent pebbles; strongly acid, (pH 5.2); clear smooth boundary. (1 to 3 inches thick)
A--1 to 6 inches; yellowish brown (10YR 5/4) crushed very gravelly ashy sandy loam, dark brown (10YR 3/3) crushed moist; weak fine subangular blocky structure; soft, very friable, slightly sticky, nonplastic; many very fine to coarse roots; many very fine interstitial and few very fine tubular pores; 45 percent pebbles; strongly acid, (pH 5.2); clear wavy boundary. (2 to 5 inches thick)
Bw1--6 to 15 inches; yellowish brown (10YR 5/4) crushed very gravelly ashy sandy loam, dark yellowish brown (10YR 3/4) crushed moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky, nonplastic; common very fine and fine roots and many medium and coarse roots; few very fine tubular and many very fine interstitial pores; 55 percent pebbles; slightly acid, (pH 6.1); clear wavy boundary. (7 to 12 inches thick)
Bw2--15 to 23 inches; light yellowish brown (10YR 6/4) crushed extremely gravelly ashy sandy loam, dark yellowish brown (10YR 4/4) crushed moist; weak fine subangular blocky structure; soft, very friable, slightly sticky, nonplastic; many fine to coarse roots and common very fine roots; few very fine tubular and many very fine interstitial pores; 65 percent pebbles; slightly acid, (pH 6.2); clear wavy boundary. (7 to 12 inches thick)
Bw3--23 to 30 inches; pale brown (10YR 6/3) crushed extremely gravelly ashy sandy loam, brown (10YR 4/3) crushed moist; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine to coarse roots; common very fine tubular and many very fine interstitial pores; 75 percent pebbles; slightly acid, (pH 6.2); gradual wavy boundary. (0 to 9 inches thick)
Cr--30 to 36 inches; weathered andesitic tuff-breccia.
TYPE LOCATION: Modoc County, California; on the Modoc National Forest in the Warner Mountains 1,100 feet north and 2,600 feet west of the southeast corner of section 5, T 47N., R 16E.; Mount Bidwell USGS 7.5 minute topographic quadrangle; 41 degrees 58 minutes 5 seconds north latitude and 120 degrees 9 minutes 48 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 - 44 to 47 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.
Depth to bedrock - 20 to 40 inches to a paralithic contact. The paralithic materials below the contact are weathered pyroclastic andesitic tuff.
Profile reaction - Slightly acid to strongly acid.
Particle-size control section - Clay content: Averages 10 to 18 percent, (field estimates).
Rock fragments: Averages 60 to 80 percent, mainly gravel.
A horizons - 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.
Bw horizons - Hue: 10YR or 7.5YR.
Texture: Ashy loam or ashy sandy loam.
Clay content: 10 to 18 percent.
Rock fragments: averages 60 to 80 percent, subhorizons with 35 to 60 percent rock fragments are in some pedons.
Structure: Weak to strong, fine to coarse subangular blocky.
COMPETING SERIES: These are the Azwell, Bamber. Fears, Hallihan, Madrock, Terence, Tiptop, and Wuki soils. Azwell and Madrock soils have lithic contacts within 30 to 40 inches. Bamber. Fears, Hallihan, Terence, Tiptop, and Wuki soils have depth to bedrock of more than 40 inches.
GEOGRAPHIC SETTING: Gurlidawg soils are on mountains. They formed in volcanic ash and colluvium over residuum derived from andesitic tuff. Slopes are 4 to 50 percent. Elevations range from 6,540 to 8,800 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 30 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Paynepeak and Pryopatti series. Both of these soils have a mollic epipedon and have bedrock at depths of 40 to 60 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium or high surface runoff; moderate permeability.
USE AND VEGETATION: Gurlidawg soils are used for timber production, watershed, wildlife habitat, and limited livestock grazing. The vegetation consists of lodgepole pine with an understory of perennial forbs, sedges and bluegrass. Some phases of this soil have whitebark pine forest vegetation.
DISTRIBUTION AND EXTENT: Northeastern California and southern Oregon. These soils are not extensive. MLRA 21.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Lake County, Oregon, Southern Part, 2006. The soil was originally proposed in Surprise Valley-Home Camp Area, California and Nevada, 2005.
REMARKS: The name is coined
Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon - The zone from the soil surface to 7 inches (Oe, A and part of the Bw1 horizon).
Andic properties -- High volcanic glass content in the .02 to 2mm fraction from the mineral soil surface to 30 inches and acid-oxalate extractable aluminum and iron of .4 or more (A, Bw1, Bw2and the Bw3 horizons).
Cambic horizon - The zone from 6 to 30 inches (Bw1, Bw2 and Bw3 horizons).
Paralithic contact - The boundary at 30 inches to underlying soft, weathered bedrock (Cr layer).
Particle-size control section - The zone from 11 (10 inches below the mineral soil surface) to 30 inches (part of the Bw1, Bw2 and Bw3 horizons).