LOCATION HALLIHAN OREstablished Series
TAXONOMIC CLASS: Ashy-skeletal, glassy Xeric Vitricryands
TYPICAL PEDON: Hallihan gravelly fine sandy loam, in forest on a 16 percent north facing slope. (Colors are for moist soil unless otherwise noted.)
0i--2 inches to 0; white fir and lodgepole pine needles.
A1--0 to 2 inches; black (10YR 2/1) gravelly fine sandy loam, dark grayish brown (10YR 4/2) dry; weak very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many roots; many irregular pores; 20 percent gravel; slightly acid (pH 6.5); abrupt smooth boundary. (1 to 5 inches thick)
A2--2 to 6 inches; dark brown (10YR 3/3) gravelly fine sandy loam, brown (10YR 5/3) dry; weak very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many roots; many irregular pores; 15 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (3 to 7 inches thick)
AB--6 to 13 inches; dark yellowish brown (10YR 4/4) gravelly fine sandy loam, yellowish brown (10YR 5/4) dry; weak very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many roots; many irregular pores; 5 percent cobbles, 15 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (0 to 8 inches thick)
Bw--13 to 21 inches; dark yellowish brown (10YR 4/4) very gravelly fine sandy loam, light yellowish brown (10YR 6/4) dry; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; common roots; few very fine tubular pores; 40 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (7 to 16 inches thick)
C1--21 to 33 inches; pale brown (10YR 6/3) very gravelly sandy loam, very pale brown (10YR 7/3) dry; massive; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots and few medium and coarse; common very fine and fine irregular pores; 55 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (10 to 20 inches thick)
C2--33 to 43 inches; pale brown (10YR 6/3) very gravelly sandy loam, white (10YR 8/2) dry; massive; slightly hard, very friable, slightly sticky and nonplastic; few roots; common irregular pores; 55 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (8 to 13 inches thick)
C3--43 to 60 inches; pale brown (10YR 6/3) extremely gravelly sandy loam, white (10YR 8/2) dry; massive; slightly hard, very friable, nonsticky and nonplastic; few roots; few irregular pores; 25 percent cobbles, 60 percent gravel; moderately acid (pH 6.0).
TYPE LOCATION: Lake County, Oregon; NW1/4, SW1/4 of section 31, T. 37 S., R. 22 E.
RANGE IN CHARACTERISTICS: The soils are moist in the winter and spring and are dry for 45 to 60 consecutive days after the summer solstice. The mean annual soil temperature is 40 to 45 degrees F. The mean summer soil temperature is 44 to 47 degrees F. The soil temperature is above 41 degrees F. from about June to November (5 months). The bulk density of the fine earth fraction is 0.85 to 0.95 grams per cubic centimeter. Depth to bedrock is 60 inches or more. The particle-size control section averages 35 to 60 percent rock fragments of which 0 to 15 percent are cobbles and stones and 35 to 45 percent are gravel. The fragments are mainly rhyolite. It has 7 to 18 percent clay. The very fine sand fraction contains 50 to 70 percent glass. It is moderately to slightly acid.
The A horizon has value of 2 to 4 when moist and 4 or 5 when dry, and chroma of 1 to 4 when moist and dry.
The Bw horizon has value of 3 or 4 when moist and 6 or 7 when dry, and chroma of 4 to 6 when moist and dry. It is sandy loam or fine sandy loam with 7 to 18 percent clay. Rock fragments range from 35 to 60 percent of which 0 to 15 percent are cobbles and stones and 35 to 50 percent are gravel.
The C horizon has value of 4 to 6 when moist and 6 to 8 when dry, and chroma of 2 to 4 when moist and dry. It is sandy loam. Rock fragments range from 50 to 85 percent of which 10 to 25 percent are cobbles and stones and 40 to 60 percent are gravel.
COMPETING SERIES: There no competing series.
GEOGRAPHIC SETTING: Hallihan soils are on mountainsides at elevations of 6,300 to 7,200 feet. Slopes are 0 to 60 percent. The soils formed in colluvium and residuum weathered primarily from rhyolite. The climate is cold and moist in winters and cool and dry in summers. The mean annual precipitation is 30 to 34 inches. The mean annual temperature is 41 to 43 degrees F. The frost-free period is 20 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the proposed Chocktoot, Hammersley, Kittleson, Longjohn, and Twelvemile soils. Chocktoot and Hammersley soils have a mollic epipedon. Kittleson soils are ashy in the particle-size control section. Longjohn soils have a base saturation of less than 50 percent between 10 and 30 inches. Twelvemile soils have a frigid soil temperature regime.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: The soils are used primarily for timber production, watershed, wildlife habitat, and recreation. Vegetation is primarily white fir, sticky currant and wheeler bluegrass.
DISTRIBUTION AND EXTENT: South central Oregon, MLRA 21. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, Oregon; Southern Part, 1991.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - 0 to 6 inches (A1 and A2 horizons)
Cambic horizon - 13 to 21 inches (Bw horizon)
Classification into Andisols is based on laboratory data (glass count and 15 bar water) for the associated Twelvemile series. Phosphorous retention is assumed to be greater than 25 percent and acid oxylate extractable aluminum plus one-half of the acid oxylate extractable iron is assumed to be greater than 0.4 percent.
ADDITIONAL DATA: Forest Service vegetative site CW-C4-11.