LOCATION ASTA CAEstablished Series
TAXONOMIC CLASS: Medial, amorphic, mesic Ultic Haploxerands
TYPICAL PEDON: Asta gravelly sandy loam - on a northeast facing convex slope of ll percent under black oak, Douglas fir and ponderosa pine, snowberry and blue blossom ceanothus at 3,280 feet elevation. (Colors are for dry soil unless otherwise stated. When described (6/4/74) the soil was moist (near field capacity) throughout.)
02--2 to 1 inch; new needles, leaves, bark, twigs and other organic debris.
01--1 inch to 0; partially decomposed needles, leaves, twigs, bark and other organic debris.
A11--0 to 3 inches; dark brown (7.5YR 4/4) gravelly sandy loam, black (5YR 2/1) moist; weak fine granular structure; soft, very friable, slightly sticky and nonplastic; many very fine, fine and medium roots; many fine interstitial pores; 25 percent fine (2 to 5 mm) iron concretions and rounded pebbles; weakly smeary; very strongly acid (pH 4.8); abrupt smooth boundary. (1 to 4 inches thick)
A12--3 to 6 inches; dark brown (7.5YR 4/4) gravelly sandy loam, dark reddish brown (5YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and nonplastic; many very fine, fine and medium roots; many fine interstitial pores; 30 percent fine (2 to 5 mm) iron concretions and rounded pebbles; weakly smeary; very strongly acid (pH 5.0); abrupt smooth boundary. (2 to 4 inches thick)
A3--6 to 13 inches; brown (7.5YR 5/4) gravelly sandy loam, dark reddish brown (5YR 3/4) moist; very weak medium subangular blocky structure parting to moderate fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many fine interstitial pores; 30 percent fine (2 to 5 mm) iron concretions and rounded pebbles; weakly smearly; very strongly acid (pH 5.0); clear smooth boundary. (6 to 10 inches thick)
B1--13 to 20 inches; brown (7.5YR 5/4) loam, reddish brown (5YR 4/4) moist; moderate fine granular structure; slightly hard, friable, sticky and plastic; many medium and common very fine and fine roots; few very fine tubular pores; strongly acid (pH 5.5); abrupt wavy boundary.
Bt--20 to 27 inches; brown (7.5YR 5/4) loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure parting to moderate fine granular; hard, friable, sticky and plastic; many medium and common very fine and fine roots; common very fine vesicular and few very fine tubular pores; common thin clay films in pores and on peds; strongly acid (pH 5.5); abrupt wavy boundary. (6 to 11 inches thick)
2Bt1--27 to 34 inches; strong brown (7.5YR 5/6) loam (near silt loam), reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; many medium and few very fine and fine roots; common very fine and fine tubular and few very fine vesicular pores; continuous thin clay films in pores and on peds; strongly acid (pH 5.5); clear wavy boundary. (4 to 9 inches thick)
2Bt2--34 to 50 inches; strong brown (7.5YR 5/6) silt loam, reddish brown (5YR 4/4) moist; massive; hard, friable, sticky and plastic; many medium and few very fine and fine roots; common very fine and fine tubular and few very fine vesicular pores; continuous thin clay films in pores; 5 percent fine (2 to 5 mm) rounded pebbles; strongly acid (pH 5.5); clear wavy boundary. (12 to 26 inches thick)
2Bt3--50 to 60 inches; strong brown (7.5YR 5/6) silt loam, reddish brown (5YR 4/4 moist; massive; hard, friable, sticky and plastic; many medium and few very fine and fine roots; common very fine and fine tubular and few very fine vesicular pores; few thick clay films on pebbles and many thin clay films in pores; 5 percent fine (2 to 5 mm) rounded pebbles; slightly smeary; strongly acid (pH 5.5); abrupt wavy boundary. (5 to 12 inches thick)
3C--60 to 71 inches; strong brown (7.5YR 5/6) dry and moist, silt loam; massive; hard, friable sticky and plastic; many medium and few very fine and fine roots; few very fine and fine tubular pores; slightly smeary; very strongly acid (pH 5.5).
TYPE LOCATION: Siskiyou County, California; about 70 feet north of a narrow dirt road. Approximately 0.5 mile south of Lake Siskiyou; approximately 1,680 feet south and 800 feet west of the northeast corner sec. 32, T. 40 N., R. 4 W.
RANGE IN CHARACTERISTICS: The soil is 60 inches or more deep to softly consolidated, tuff-like, glacial outwash or till. The mean annual soil temperature is 47 to 56 degrees F. The soil temperature exceeds 41 degrees F. from April 1 to November 15 and exceeds 47 degrees F. from May 1 to November 1. The soil between the depths of 8 and 24 inches is dry from July 15 to October 15 and is moist in some or all parts the rest of the year. The amount of rock fragments on the soil surface is 0 to 5 percent cobbles, 10 to 30 percent rounded gravel, and iron concretions that are 2 to 15 mm in diameter. The amount of rock fragments throughout the soil profile range from 0 to 25 percent and consists of rounded cobbles and medium, fine and very fine rounded gravel. The weighted average of the upper 20 inches of the argillic horizon ranges from 0 to 35 percent. The rounded gravel are commonly more plentiful in the upper 20 to 40 inches. About 0 to 15 percent of the fragments are Fe/Mn concretions. The bulk density ranges from 0.6 to 1 g/cc to a depth of 10 to 20 inches but is 0.85 g/cc or more at a depth of 10 to 14 inches.
The A horizon is dark brown, brown, reddish yellow, strong brown, yellowish brown or 1ight yellowish brown (10YR 3/3, 4/3, 5/3, 5/4, 5/6, 6/4; 7.5YR 3/2, 4/4, 5/2, 5/4, 5/6, 6/6). Moist color is black, dark reddish brown, reddish brown, dark brown, very dark grayish brown or very dark brown (5YR 2/1, 2/2, 3/2, 3/3, 3/4, 4/3, 4/4, 5/3, 5/4; 7.5YR 3/2; 10YR 2/2, 3/2, 3/3). It is coarse sandy loam, sandy loam, or loam with 10 to 15 percent clay and may have gravelly or cobbly modifiers. It is very strongly acid to slightly acid and the base saturation ranges from 25 to 45 percent. The NaF pH ranges from 9.0 to 10.0.
The Bt and 2Bt horizons are reddish yellow, yellowish red, yellow, strong brown, brown, dark brown, pale brown, very pale brown (5YR 5/6, 6/6; 7.5YR 4/2, 4/4, 5/2, 5/4, 5/6; 10YR 3/3, 4/3, 5/3, 6/2, 7/3, 7/4, 7/6). Moist color is yellowish red, reddish yellow, reddish brown, strong brown or dark brown (5YR 4/3, 4/4, 5/3, 5/4, 5/6; 7.5YR 4/2, 4/4, 5/6, 6/6, 6/8). They are loam or silt loam with 13 to 27 percent clay. The weighted average of the upper 20 to 30 inches of the argillic horizon ranges from 18 to 25 percent clay and 0.9 to 2 percent organic carbon. They are very strongly acid or strongly acid and the base saturation ranges from 25 to 35 percent. In the upper 20 inches of the argillic horizon the B.D. ranges from 1 to 1.2 g/cc.
It is common to have all or a combination of the following transitional horizons: A3, B1, B1t, B3 or B3t.
The 3C horizon is weakly to strongly cemented and tuff-like and may have very coarse vesicular cavities throughout. Textures are silt loam, loam or very fine sandy loam. The layer restricts roots but water is transmitted slowly. The material is weathering in most pedons. Some pedons lack the IIIC horizon. Some pedons have unrelated Cr horizons with paralithic contacts at depths of 60 to 80 inches.
COMPETING SERIES: These are the Arta, Cohasset, Garrard and Horseshoe series in other families. The Arta and Garrard soils have clayey control sections and umbric epipedons. Cohasset soils lack volcanic ash materials and have base saturation of 35 to 50 percent in the lower part of the argillic horizon. Horseshoe soils lack volcanic ash, have a B2t horizon with 25 to 35 percent clay and 5YR and 2.5YR hues.
GEOGRAPHIC SETTING: Asta soils are on deeply dissected terrace and terrace faces at elevations of 3,000 to 5,000 feet. The soils formed in glacial outwash from extrusive igneous rock sources with a thick overlay of fine and very fine volcanic ash. The climate is continental and subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 25 to 55 inches. Seasonal snowfall is 60 to 100 inches. Mean January temperature is 28 to 34 degrees F.; mean July temperature is 64 to 58 degrees F.; mean annual temperature is 45 to 50 degrees F. Frost-free season is 80 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boomer, Deetz, Neer, Odas, Ponto and Shasta soils. Boomer soils have base saturation greater than 35 percent in the argillic horizon and lack volcanic ash materials in the soil. Deetz and Shasta soils have ashy control sections. Neer soils are moderately deep and have a medial-skeletal control section. Odas soils are poorly drained and have a coarse-loamy control section. Ponto soils have a cambic horizon and medial control section.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability; medium runoff.
USE AND VEGETATION: Used primarily for woodland, recreation and wildlife habitat. Native vegetation is Douglas-fir, ponderosa pine, incense cedar, white fir, sugar pine, black oak, mountain whitethorn, manzanita, deerbrush, hazelbrush, gooseberry, snowberry, and a few grasses and forbs.
DISTRIBUTION AND EXTENT: North-central California near volcanic peaks. The soil is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Siskiyou County, California, 1978.
REMARKS: The soil is dry for 60 to 90 consecutive days following the summer solstice and therefore lacks a udic moisture regime. There is no placement for soils like Typic except for a with or without item b.
ADDITIONAL DATA: The soil was sampled by the Riverside Lab 6/11/74. Pedon No. S74CA093-2.
OSED scanned by SSQA. Last revised by state on 9/78.
Series reclassified 5/95. Competing series not updated at that time.