LOCATION PASTOLLA CAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Cumulic Endoaquolls
TYPICAL PEDON: Pastolla muck on a north-facing 1 percent slope under a cover of bluegrass, rushes, carex and forbs at an elevation of 3100 feet. (Colors are for moist soil unless otherwise stated. Also crushed and uncrashed are stated for moist colors where different. All dry colors are uncrushed. When described August 28, 1984, the soil was moist below 38 inches.)
Oa--0 to 5 inches; black (N 2/0) crushed, muck, very dark gray (10YR 3/1) dry; strong fine granular structure; soft, very friable, moderately smeary, nonsticky and nonplastic; many very fine roots; many very fine tubular pores; slightly alkaline (pH 7.8); abrupt smooth boundary. (0 to 9 inches thick.)
A1--5 to 10 inches; black (N 2/0) uncrushed and black (10YR 2/1) mucky silt loam, dark gray (10YR 4/1), light gray to gray (10YR 6/1), and black (10YR 2/1) crushed dry; moderate medium subangular blocky structure; slightly hard, friable, moderately smeary, slightly sticky and slightly plastic; common very fine pores; moderately alkaline (pH 8.2); abrupt smooth boundary.
A2--10 to 11 inches; black (N 2/0) , mucky silt loam, very dark gray (10YR 3/1) dry; moderate fine subangular blocky structure; slightly hard, friable, moderately smeary, slightly sticky and slightly plastic; common very fine roots and few fine roots; many very fine tubular pores; slightly effervescent; moderately alkaline (pH 8.3); abrupt smooth boundary.
A3--11 to 19 inches; black (10YR 2/1), and dark grayish brown (10YR 4/2) uncrushed, and black (10YR 2/1) crushed, mucky silt loam, gray (10YR 5/1) and light gray (10YR 6/1) dry; moderate fine subangular blocky structure; slightly hard, friable, weakly smeary, slightly sticky and slightly plastic; common very fine roots and few fine roots; many very fine tubular pores; thin strata 1/4 to 1/2 inch ashy material; strongly alkaline (pH 8.5); abrupt smooth boundary. (Combined thickness of the A horizon is 10 to 19 inches)
C1--19 to 22 inches; yellowish brown (10YR 5/4), and strong brown (7.5YR 4/6) uncrushed, and brown (7.5YR 4/4) crushed, stratified silt loam, pale brown (10YR 6/3) and yellow (10YR 7/6) dry; moderate very fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; few very fine roots and fine roots; many very fine and common fine tubular pores; strongly alkaline (pH 8.5); abrupt smooth boundary. (2 to 4 inches thick)
C2--22 to 29 inches; very dark gray (10YR 3/1) silty clay, light gray to gray (10YR 6/1) and light gray (10YR 7/1) dry; moderate medium subangular blocky structure; hard, friable, moderately smeary, slightly sticky and slightly plastic; few very fine roots; many very fine and fine tubular pores; small pieces of obsidian and fibers of organic matter; moderately alkaline (pH 8.3); abrupt smooth boundary. (6 to 8 inches thick)
C3--29 to 38 inches; dark grayish brown (10YR 4/2) loam, light gray (10YR 7/1) dry; massive; hard, friable, moderately smeary, slightly sticky and plastic; few very fine roots; many very fine and fine tubular pores; moderately alkaline (pH 8.3); abrupt smooth boundary. (7 to 10 inches thick)
C4--38 to 47 inches; grayish brown (10YR 5/2) clay, gray (10YR 5/1) dry; massive; very hard, friable, sticky and plastic; few very fine roots; few very fine and fine tubular pores; slightly effervescent; slightly alkaline (pH 7.5);
abrupt smooth boundary. (7 to 9 inches thick)
C5--47 to 55 inches; yellowish brown (10YR 5/4) loam, light gray (10YR 7/2) dry; moderate fine subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; few very fine roots; few very fine and fine tubular pores; moderately alkaline (pH 8.1); abrupt smooth boundary. (6 to 9 inches thick)
2Btq--55 to 64 inches; dark yellowish brown (10YR 4/4), brown (7.5YR 4/4) uncrushed, and brown (7.5YR 5/4) crushed, coarse sandy loam, light gray (10YR 7/1) and brownish yellow (10YR 6/6) dry; many fine distinct reddish yellow (7.5YR 6/6) mottles; strong fine angular blocky structure; hard, very friable, slightly brittle, nonsticky and nonplastic; many clay films in pores; few very fine tubular pores; violently effervescent, desseminated; moderately alkaline (pH 8.1). (Combined thickness of the C horizons is 34 to 45 inches)
TYPE LOCATION: Shasta County, California; about 6 miles north of Fall River Mills; 900 feet south and 300 feet west of the northeast corner of the projected sec. 29, T. 38 N., R. 5 E., Fall River Mills NE (Timbered Crater) quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Depth of soil is greater than 60 inches. The mean annual soil temperature is 48 to 54 degrees F. The soil temperature exceeds 41 degrees F. from mid February to mid December (about 300 days) and exceeds 47 degrees F. from mid April to mid November. The soil moisture control section is always moist unless drained. Calcium carbonate equivalent ranges to 2 percent in calcareous horizons.
The O horizon color is N 2/0; 10YR 5/1, 4/1, or 3/1 dry. Moist color is N2/0; 10YR 3/1, or 2/1. Organic matter ranges from 25 to 30 percent. Clay content ranges from 30 to 35 percent. Bulk density is 0.35 to 0.45 g/cc. Reaction is neutral to moderately alkaline.
The A horizon color is 10YR 2/1, 3/1, 4/1, 4/2, 5/1, 6/1 or N 2/0 dry. Moist color is 10YR 2/1, 3/1, 3/2, 4/1, or N 2/0. Mottles are 10YR 6/1, 2/1; 2.5YR 5/4 and 2.5Y 4/4; N 2/0 moist. Organic matter ranges from 8 to 20 percent. Texture is stratified silt loam or silty clay loam. Clay contents ranges from 25 to 35 percent. Bulk density is 0.45 to 0.50 g/cc. Reaction is moderately alkaline to very strongly alkaline.
The C horizon has color value of 5 to 8; chroma of 1 to 6; and hue of 10YR dry. Moist color has a value of 5 to 3; chroma of 4 to 6; and hue of 10YR and 7.5YR. Organic matter ranges from .2 to 10.0 and is percent usually less than 1 percent below 25 inches. Texture is stratified silt loam, loam, silty clay, and clay. Clay content ranges from 10 to 45 percent. Bulk density is 0.25 to 1.00 g/cc. Reaction is moderately alkaline to very strongly alkaline.
COMPETING SERIES: There are no competing.
GEOGRAPHIC SETTING: Pastolla soils are in basins and on low stream terraces. Slopes are 0 to 2 percent. These soils formed in stratified alluvium weathered from ash and lake sediments. Elevation is 3300 to 4180 feet. The climate is semiarid with warm dry summers and cold moist winters. Mean annual precipitation is 12 to 20 inches. Snowfall is 12 to 36 inches. The mean annual temperature is 48 to 52 degrees F. The mean January temperature is about 32 degrees F. The mean July temperature is about 68 degrees F. Frost-free season is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Henhill (T), Pit and Whipple (T) series. The Henhill soils are fine-loamy and on stream terraces. The Pit soils have a fine textured control section. The Whipple soils have a fine textured control section, a natric horizon, and are moderately deep.
DRAINAGE AND PERMEABILITY: Very poorly drained; ponded to slow runoff; slow permeability. Unless protected these soils are flooded for periods of many weeks in December to April. Unless drained, a water table occurs at depth of less than 12 inches from October through April and 12 to 40 inches May through September.
USE AND VEGETATION: This soil is mainly used for wildlife habitat and pasture. The existing vegetation is tules, carex, canary grass, and Kentucky bluegrass.
DISTRIBUTION AND EXTENT: Northeastern California. The soils are not extensive. MLRA is 21.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Shasta County, Intermountain Soil Survey Area, California 1994. Source of name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
The series was formerly classified as medial over loamy, mixed, mesic Histic Endoaquands. It was reclassified due to additional laboratory data. It was changed to the current classification because the Fe and Al oxalate values were very low and did not meet the andic soil properties for andisols or an andic subgroup. It did not have an Ap horizon and therefore did not meet the organic carbon and clay requirements for a histic epipedon.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.
ADDITIONAL DATA: This pedon was characterized by the NSSL in 1984. Pedon number is S 84CA-089-002 unpublished.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.