LOCATION MUDPOT OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Chromic Endoaquerts
TYPICAL PEDON: Mudpot silty clay, rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 5 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; weak medium prismatic and moderate fine platy structure; slightly hard, very friable, sticky and slightly plastic; few very fine roots; common very fine and many fine vesicular pores; moderately alkaline (pH 8.0); gradual smooth boundary. (3 to 15 inches thick)
Bw--5 to 14 inches; light brownish gray (2.5Y 6/2) silty clay, grayish brown (2.5Y 5/2) moist; few fine prominent dark reddish brown (5YR 3/3) mottles; weak fine subangular blocky structure; hard, firm, sticky and plastic; few very fine and fine roots; few very fine vesicular pores; few slickensides; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 20 inches thick)
Bkss--14 to 49 inches; light brownish gray (2.5Y 6/2) silty clay, grayish brown (2.5Y 5/2) moist; moderate coarse subangular blocky structure; hard, firm, sticky and plastic; few very fine roots; few very fine tubular pores; many slickensides; slightly effervescent; lime segregated in common rounded medium sized soft masses; moderately alkaline (pH 8.4) clear smooth boundary. (10 to 40 inches thick)
Bk--49 to 60 inches; light gray (2.5Y 7/2) silty clay, grayish brown (2.5Y 5/2) moist; massive; hard, firm, sticky and plastic; few very fine roots; common very fine tubular pores; strongly effervescent; lime segregated in common rounded medium sized soft masses; moderately alkaline (pH 8.4).
TYPE LOCATION: Lake County, Oregon; about 1,200 feet east of BLM road 6106, in the north end of Guano Lake, in the SE1/4SW1/4 of sec. 15, T. 39 S., R. 27 E.
RANGE IN CHARACTERISTICS: The soil is inundated with water during the winter and early spring. The mean annual soil temperature is 45 to 47 degrees F. Depth to mottles is 3 to 15 inches. Depth to carbonates is 10 to 30 inches. The subsoil cracks and develops slickensides; cracks extend upward to the base of the A horizon. The cracks are open from about mid-August through mid-November. The particle-size control section averages 0 to 5 percent gravel and 40 to 60 percent clay. Hue is 2.5Y or 5Y.
The A horizon has value of 5 to 7 dry, 3 or 4 moist, and chroma of 1 or 2 dry, 2 moist.
The Bw horizon is clay, silty clay, or silty clay loam. It has value of 6 or 7 dry, 4 or 5 moist, and chroma of 1 or 2 dry and moist.
The Bk horizon is silty clay or clay. It has value of 6 or 7 dry, 4 or 5 moist, and chroma of 1 or 2 dry and moist.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Mudpot soils are in lake basins. Slopes are 0 to 2 percent. Elevations range from 4,900 to 5,200 feet. The soils formed in lacustrine sediments derived primarily from basalt and tuff. Water ponds in winter and spring after snow melt and heavy rains. The mean annual precipitation is 8 to 12 inches. The mean annual temperature is 43 to 45 degrees F. The frost-free period is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boulder Lake, Langslet, Spangenburg, and Swalesilver soils. Boulder Lake soils crack to the surface. Langslet soils are somewhat poorly drained, have an aridic soil moisture regime, and are on the adjacent higher terrace. Spangenburg and Swalesilver soils have an argillic horizon and are on the higher terraces.
DRAINAGE AND PERMEABILITY: Poorly drained; ponded; slow permeability. A water table is at plus 1 to 1.0 feet from January to July.
USE AND VEGETATION: The soils are used for wildlife habitat and limited livestock grazing. The present vegetation is mainly foxtail barley and curly dock.
DISTRIBUTION AND EXTENT: Basin areas of southeastern Oregon, MLRA 24. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, Oregon, Southern Part; 1991.
REMARKS: This series is not presently classified as a vertisol because the cracks do not extend through the A horizon to the surface. The proposed changes to Soil Taxonomy will probably place this series as Aquerts
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - moist value of 4 and 5 to a depth of 14 inches.
Cambic horizon - the zone from 4 to 60 inches.
Aquic soil moisture regime - mottling with chroma of 2 or less from 5 to 14 inches.
Typic subgroup of Haplaquepts - moist chroma of 2 or less throughout the profile.