LOCATION WORMCREEK IDEstablished Series
TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid Vitrandic Calcixerolls
TYPICAL PEDON: Wormcreek gravelly ashy clay loam--on a 48 percent slope--rangeland. (Colors are for dry soil unless otherwise noted. When described on September 5, 1984, the soil was dry to 15 inches and moist below.)
A1--0 to 4 inches; dark grayish brown (10YR 4/2) gravelly ashy clay loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and few medium and coarse roots; many very fine irregular and many very fine tubular pores; 25 percent gravel and 5 percent cobbles; slightly effervescent (1 percent calcium carbonate equivalent); disseminated carbonate; slightly alkaline (pH 7.8); clear smooth boundary.
A2--4 to 9 inches; grayish brown (10YR 5/2) gravelly ashy clay loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and few medium and coarse roots; many very fine and fine and few medium tubular pores; 25 percent gravel and 5 percent cobbles; slightly effervescent (3 percent calcium carbonate equivalent); disseminated carbonate; moderately alkaline (pH 8.1); clear smooth boundary. (Combined thickness of the A horizons is 7 to 16 inches)
Bk1--9 to 15 inches; light yellowish brown (10YR 6/4) very gravelly ashy clay loam, brown (7.5YR 5/4) moist; moderate medium and fine angular blocky structure; hard, very friable, slightly sticky and slightly plastic; many very fine and fine and few medium and coarse roots; many very fine and fine and common medium tubular pores; 35 percent gravel and 10 percent cobbles; strongly effervescent (23 percent calcium carbonate equivalent); disseminated carbonate; moderately alkaline (pH 8.3); clear wavy boundary.
Bk2--15 to 22 inches; very pale brown (10YR 8/2) very cobbly ashy clay loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; many very fine, common fine and few medium roots; many very fine and fine irregular pores; 25 percent gravel and 25 percent cobbles; violently effervescent (31 percent calcium carbonate equivalent); thin patchy carbonate coats on bottoms of rock fragments; moderately alkaline (pH 8.3); clear wavy boundary.
Bk3--22 to 31 inches; very pale brown (10YR 8/2) very cobbly ashy loam, very pale brown (10YR 7/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; many very fine and fine irregular pores; 25 percent gravel and 30 percent cobbles; violently effervescent (30 percent calcium carbonate equivalent); many thick carbonate coats on bottoms of rock fragments; moderately alkaline (pH 8.3); clear wavy boundary.
Bk4--31 to 41 inches; very pale brown (10YR 8/3) extremely cobbly ashy loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine and fine and medium roots; many very fine and fine irregular pores; 25 percent gravel, 40 percent cobbles, and 5 percent stones; strongly effervescent (27 percent calcium carbonate equivalent); disseminated carbonate; strongly alkaline (pH 8.5); clear wavy boundary. (Combined thickness of the Bk horizons is 30 to 45 inches)
BC--41 to 48 inches; very pale brown (10YR 8/3) extremely cobbly ashy loam, brownish yellow (10YR 6/6) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; many very fine and fine irregular pores; 30 percent gravel, 35 percent cobbles, and 5 percent stones; strongly effervescent (17 percent calcium carbonate equivalent); disseminated carbonate; strongly alkaline (pH 8.9); clear smooth boundary. (3 to 14 inches thick)
Cr--48 to 60 inches; soft vitric tuff.
TYPE LOCATION: Franklin County, Idaho; about 5 miles east and 4 miles north of Preston; approximately 500 feet east and 2,000 feet south of the northwest corner of section 33, T. 15 S., R. 40 E.; USGS Riverdale 7.5 minute topographic quadrangle; 42 degrees, 09 minutes, 50 seconds north latitude and 111 degrees, 47 minutes, 49 seconds west longitude, NAD83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 44 to 46 degrees F.
Mollic epipedon thickness - 7 to 16 inches.
Depth to calcic horizon - 7 to 16 inches.
Depth to bedrock - 40 to 60 inches to a paralithic contact. The paralithic materials below the contact are soft, vitric tuff.
Particle-size control section - Clay content: Averages 18 to 28 percent;
Rock fragments: 40 to 75 percent. Lithology of fragments is volcanic rock such as tuff.
Volcanic glass content - 50 to 65 percent in coarse silt through very coarse sand fractions.
A horizons
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 to 4 percent.
Reaction: Slightly alkaline or moderately alkaline.
Bulk density: 1.10 to 1.30 grams per cubic centimeter.
Oxalate extractable aluminum plus one-half iron: 0.14 to 0.17 percent.
Phosphorous retention: 15 to 25 percent.
15-bar water retention on air dried samples: 15 to 25 percent.
Bk1 and Bk2 horizons
Hue: 10YR or 7.5YR.
Value: 5 through 8 dry, 5 through 7 moist.
Chroma: 2 through 6, dry or moist.
Texture: Very gravelly ashy clay loam or very cobbly ashy clay loam.
Clay content: 27 to 35 percent.
Calcium carbonate equivalent: 20 to 35 percent.
Bulk density: 1.00 to 1.20 grams per cubic centimeter.
Oxalate extractable aluminum plus one-half iron: 0.04 to 0.12 percent.
Phosphorous retention: 30 to 80 percent.
15-bar water retention on air dried samples: 10 to 25 percent.
Bk3, Bk4, and BC horizons
Hue: 10YR or 7.5YR.
Value: 5 through 8 dry, 5 through 7 moist.
Chroma: 2 through 6, dry or moist.
Texture: Very cobbly ashy loam or extremely cobbly ashy loam.
Clay content: 14 to 18 percent.
Reaction: Moderately alkaline or strongly alkaline.
Calcium carbonate equivalent: 15 to 30 percent.
Bulk density: 1.00 to 1.10 grams per cubic centimeter.
Oxalate extractable aluminum plus one-half iron: 0.04 to 0.12 percent.
Phosphorous retention: 30 to 80 percent.
15-bar water retention on air dried samples: 10 to 25 percent.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Wormcreek soils are on mountains. They typically occur on backslope and footslope positions. These soils formed in alluvium, colluvium and residuum derived from vitric tuff. Slopes are 15 to 60 percent. Elevations range from 4,800 to 6,500 feet. The mean annual precipitation is 13 to 18 inches, the mean annual air temperature is 43 to 47 degrees F., and the frost-free period is 70 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Copenhagen, Lonigan, and Manila soils. Copenhagen and Lonigan soils are less than 40 inches deep to bedrock. Manila soils have a fine particle-size control section. Copenhagen and Lonigan soils are on ridges and convex slopes. Manila soils are on lower, concave slopes.
DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; moderately slow permeability (moderately high saturated hydraulic conductivity).
USE AND VEGETATION: Wormcreek soils are used for rangeland. The native vegetation is mountain big sagebrush, bluebunch wheatgrass, and antelope bitterbrush.
DISTRIBUTION AND EXTENT: Southeastern Idaho. These soils are not extensive with about 2,400 acres of the series mapped to date. MLRA 13.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Franklin County, Idaho, 1997. The name is taken from a local creek.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 9 inches (A1 and A2 horizons).
Calcic horizon - The zone from 9 to 41 inches (The Bk1, Bk2, Bk3, and Bk4 horizons)
Paralithic contact - The boundary at 48 inches to underlying soft, weathered bedrock (Cr layer).
Particle-size control section and ashy-skeletal substitute class with glassy mineralogy - The zone from 10 to 40 inches (Bk2 and Bk3 horizons and parts of the Bk1 and Bk4 horizons).
ADDITIONAL DATA: This soil was sampled for analysis at the Soil Survey Laboratory (SSL), Lincoln, NE. The soil survey sample number is S89ID-041-005 (pedon #89P0826).