LOCATION SWAINOW CAEstablished Series
TAXONOMIC CLASS: Medial-skeletal over loamy-skeletal, mixed over isotic, frigid Ultic Haploxerands
TYPICAL PEDON: Swainow very stony sandy loam, forested, on a 30 percent east facing slope under white fir at 5,960 feet elevation. (When described September 12, 1983, the soil was dry throughout. Colors are for dry soil unless otherwise noted).
Oi--2 to 0 inches; decomposing fir needles and twigs.
A--0 to 3 inches; brown (7.5YR 4/4) very stony sandy loam, dark reddish brown (5YR 3/3) moist; weak fine granular structure; loose, very friable, nonsticky and slightly plastic; common very fine roots; many very fine interstitial pores; 20 percent stones, 25 percent 2 to 5 mm pebbles and 25 percent 5 to 75 mm pebbles; sodium fluoride pH is 10.8; slightly acid (pH 6.5); clear wavy boundary (2 to 6 inches thick).
AB--3 to 18 inches; strong brown (7.5YR 4/6) extremely stony sandy loam, dark reddish brown (5YR 3/4) moist; weak very fine subangular blocky structure; loose, very friable, nonsticky and slightly plastic; many very fine, fine and medium roots; many very fine interstitial pores; 60 percent stones and 15 percent pebbles; sodium fluoride pH is 10.6; slightly acid (pH 6.5); clear wavy boundary. (14 to 22 inches thick)
2Bt1--18 to 24 inches; yellowish red (5YR 5/6) very gravelly loam, yellowish red (5YR 4/6) moist; weak very fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many very fine tubular pores, few thin clay films on peds; 5 percent cobbles, 25 percent 2 to 5 mm pebbles and 20 percent 5 to 75 mm pebbles; sodium fluoride pH is 10.3; slightly acid (pH 6.1); clear wavy boundary.
2Bt2--24 to 35 inches; strong brown (7.5YR 5/6) very gravelly loam, yellowish red (5YR 4/6) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, few fine and medium roots; many very fine tubular pores; many thin clay films on peds; 5 percent cobbles, 25 percent 5 to 75 mm pebbles and 25 percent 2 to 5 mm pebbles; slightly acid (pH 6.1); clear wavy boundary. (The combined thickness of the 2Bt horizons is 16 to 30 inches).
2BC--35 to 44 inches; yellowish brown (10YR 5/6) extremely stony loam, dark yellowish brown (10YR 4/6) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine interstitial pores; 20 percent stones, 40 percent cobbles and 20 percent pebbles; slightly acid (pH 6.1); abrupt wavy boundary. (8 to 12 inches)
2Cr--44 to 60 inches; moderately weathered, unfractured volcanic rock; slakes in water after soaking 24 hours.
TYPE LOCATION: Plumas County, California; about 5 miles N of Clear Creek; at the SE corner of the NE 1/4 of the NW 1/4 of section 15, T.29 N., R.8 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature varies from 44 to 46 degrees F. The thickness of the solum and depth to a lithic or paralithic contact ranges from 40 to 60 inches. The soil moisture control section (10 to 35 inches) is dry in all parts from August 1 to November 1 (90 days) and is moist in some or all parts the rest of the time. The soil temperature exceeds 41 degrees F from May 1 to December 1 and exceeds 47 degrees F from June 1 to November 1. Rock fragments on the surface range from 5 to 20 percent stones; 0 to 10 percent cobbles and 20 to 40 percent gravel. The bulk density at 1/3 bar moisture ranges from 0.7 to 1.1 g/cc.
The A and AB horizon is 10YR 4/4; 7.5YR 4/2, 4/4, 4/6, 5/6; 5YR 4/6 or 5/6. Moist colors are 5YR 3/2, 3/3, 3/4 or 4/4. Rock fragments ranges from 5 to 60 percent stones, 0 to 5 percent cobbles and 15 to 50 percent gravel. Sodium fluoride pH ranges from 10.0 to 11.0. Base saturation by sum of cations ranges from 20 to 35 percent. The moist chroma of the upper 7 inches, when mixed, is greater than 3.5.
The 2Bt horizon is 7.5YR 5/4, 5/6; 5YR 5/4 or 5/6. Moist color is 7.5YR 4/4, 4/6; 5YR 4/4 or 4/6. It has 18 to 27 percent clay modified by 40 to 70 percent rock fragments mostly cobbles and gravel. Reaction is medium or slightly acid. Sodium fluoride pH ranges from less than 9.0 to 10.3 and decreases with depth. Base saturation by sum of cations ranges from 20 to 50 percent and increases with depth.
Andic property data (see remarks for explanation):
Depth P-ret B.D. pHNaf Glass Alo Feo 15barH2o
0-3 90 0.76 10.8 ND 2.5 0.5 17.1
3-18 90 0.90 10.6 ND 2.2 0.5 19.7
18-24 88 0.96 10.3 ND 1.0 0.5 19.3
24-35 80 1.05 9.8 ND 0.6 0.3 18.3
35-44 78 0.93 9.5 ND ND ND 16.6
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Swainow soils are on plateaus and mountain back slopes. Slopes are 2 to 50 percent. These soils formed in residuum and colluvium from basalt and andesite capped with a mantle of volcanic ash. Elevation is 4,510 to 6,300 feet. The climate is subhumid mesothermal with warm dry summers and cold moist winters. The mean annual precipitation is about 30 to 40 inches with 60 to 100 inches of snow. The mean annual temperature is about 44 degrees F, mean July temperature is about 60 degrees F and the mean January temperature is about 26 degrees F. The frost-free season is 60 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Almanor(T) and Redriver soils. Almanor soils are medial-skeletal and are moderately deep. Redriver soils are 20 to 40 inches deep.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderate permeability.
USE AND VEGETATION: Used for timber production. The vegetation is mainly Jeffrey pine, sugar pine, white fir, squawcarpet, whitethorn and manzanita.
DISTRIBUTION AND EXTENT: Northern California, Eastern Plumas and Western Lassen counties. The soils of this series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Plumas County, California. Susanville Area, California, Parts of Lassen and Plumas Counties, Soil Survey Area; 1985.
REMARKS: This series was classified as loamy-skeletal, mixed,frigid Ultic Haploxeralfs. With the addition of the Andisol order, the classification is changed.
Lab characterization samples S84-CA-063-02-1 through 6, August 1984. Diagnostic horizons and features recognized in this pedon:
Ochric epipedon-zone from the soil surface to a depth of 18 inches (A, AB horizons).
Andic Soil Properties-zone from the soil surface to a depth of 18 inches (A, AB horizons).
Argillic horizon-zone from 18 to 35 inches. (2Bt1, 2Bt2 horizons).
Paralithic contact-44 inches (2Cr horizon).
Andic property data definitions:
P-ret: phosphate retention of the less than 2mm fraction.
B.D.: bulk density of the less than 2mm fraction measured at 33kPa water retention.
pH NaF: pH of soil mixed with saturated sodium floride solution.
Glass: percent volcanic glass.
Alo: acid-oxalate-extractable aluminum of the less than 2mm fraction.
Feo: acid-oxalate-extractable iron of the less than 2mm fraction.
15 bar H20: dried 1500 kPa water retention as a percent.
Data elements with a * are estimated.
NC: not calculated.
ND: not done.