LOCATION MARIPOSA CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, semiactive, mesic Typic Haploxerults
TYPICAL PEDON: Mariposa gravelly silt loam, second growth timber. (Colors are for dry soil unless otherwise noted).
0--1 to 0 inches; pine needles, duff and partly decomposed litter.
A--0 to 8 inches; pink (7.5YR 7/4) gravelly silt loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine, common fine and medium roots; many very fine and common fine pores; 20 percent pebbles; moderately acid (pH 6.0); clear smooth boundary. (2 to 12 inches thick)
Bt1--8 to 15 inches; reddish yellow (7.5YR 7/6) gravelly silt loam, yellowish red (5YR 4/6) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky, slightly plastic; common very fine, fine and medium roots; many very fine, common fine, few medium pores; few thin discontinuous clay films line pores; moderately acid (pH 5.6); clear smooth boundary. (3 to 9 inches thick)
Bt2--15 to 26 inches; reddish yellow (7.5YR 6/6) gravelly heavy silt loam, yellowish red (5YR 4/6) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky, slightly plastic; common very fine and fine, few medium roots; common very fine, few fine pores; common thin continuous clay films lining pores and ped faces; strongly acid (pH 5.5); abrupt irregular boundary. (5 to 14 inches thick)
R--26; yellow (10YR 7/6) weathered slate, yellowish brown moist with nearly vertical cleavage planes.
TYPE LOCATION: El Dorado County, California; 3/4 mile southeast of Kelsey; 1,000 feet northwest of center of section 24, T.11 N., R.10 E.
RANGE IN CHARACTERISTICS: Depth to tilted schist or slate is 20 to 35 inches. The mean annual soil temperature is 47 to 59 degrees F. The soil between depths of about 5 to 15 inches is dry in all parts from the latter part of May until some time in October and moist in some or all parts the rest of the year. Rock fragments throughout the profile are 15 to 35 percent by volume. They consist of gravel, cobbles and/or stones. The argillic horizon is interrupted by bedrock within a horizontal distance of 40 to 140 inches. Where the bedrock is within 20 inches the agrillic horizon is absent. Soil colors are variable and are generally related to rock type.
The A horizon has dry colors of 10YR or 7.5YR 4/4, 5/2, 5/4, 5/6, 6/2, 6/4, 6/6, 7/2, 7/4, or 7/6 and 10YR 5/3, 5/5, 6/3, 6/5, 7/3 or 7/5. Moist colors are 5YR3/4 or have values of 2, 3 or 4 with similar chromas as dry colors. It is loam, silt loam or very fine sandy loam modified by gravel, cobbles or stones. Organic matter in the upper 1 to 2 inches is 3 to 10 percent. It is neutral to strongly acid.
In portions of the pedon less than 20 inches deep, a cambic horizon will be present in place of the argillic horizon.
The Bt horizon when present has dry colors of 7.5YR or 5YR 4/4, 4/6, 5/4, 5/6, 5/8, 6/4, 6/6, 6/8, 7/4, 7/6, 7/8, 8/4, 8/6 or 8/8. Moist colors may be one hue redder and are typically one or two units of value lower. It is loam, silt loam, clay loam or silty clay loam modified by gravel, cobbles or stones. Clay content is 20 to 35 percent. It is moderately through very strongly acid. Base saturation is about 8 to 35 percent by sum of the cations.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: These soils are on undulating to steep mountains at elevations of 1,600 to 5,600 feet. Slope ranges from 2 to 75 percent. They formed in material from metamorphosed sedimentary rocks. The climate is moist subhumid with annual precipitation of 30 to 85 inches, warm dry summers and cool moist winters. Mean annual temperature is 50 to 57 degrees F, average January temperature is about 40 degrees F, average July temperature is about 75 degrees F. The frost-free season is about 140 to 235 days.
GEOGRAPHICALLY ASSOCIATED SOILS: Mariposa soils occur in the same general area with Aiken, Cohasset, Jocal, Laughlin, Maymen, McCarthy, Musick and Sites soils. Aiken, Jocal and Sites soils lack a lithic contact in any part above 40 inches. Cohasset and Musick soils have a base saturation of more than 35 percent and have no part less than 20 inches deep. Laughlin, Mayman and McCarthy soils lack argillic horizons.
DRAINAGE AND PERMEABILITY: Well-drained; slow to very rapid runoff; moderate permeability.
USE AND VEGETATION: Timber production is predominant, with some grazing and deciduous fruit orchards. Vegetation is typically mixed coniferous forest-shrub, with Douglas fir, white fir, ponderosa pine, sugar pine, California Black oak, Tanoak, Whiteleaf, manzanita and poison oak.
DISTRIBUTION AND EXTENT: The central and southern Sierra Nevada of California. The series is extensive.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Sacramento Valley Area Reconnaissance, California, 1913.
REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as fine-loamy, mixed, mesic Ruptic-Lithic-Xerochreptic Haploxerults. Competing series were not checked at that time. This series should not be in Lithic subgroup. Type location is not lithic and that concept has been carried to other counties.
ADDITIONAL DATA: Two non-lithic pedons sampled in Amador County: NSSL Pedon S60CA-005-0025 and S60CA-005-026.one of which is the modal for Amador published soil survey as Mariposa.