LOCATION LOGAN UT+ID NVEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Calciaquolls
TYPICAL PEDON: Logan silty clay loam, 0 to 1 percent slope-rangeland. (Colors are for air-dry soil unless otherwise stated.)
Oe--0 to 2 inches; matted roots and plant remains. (0 to 12 inches thick)
A--2 to 15 inches; very dark gray (10YR 3/1) silty clay loam, black (10YR 2/1) moist; moderate medium granular structure; slightly hard, friable, moderately sticky and moderately plastic; many fine and medium roots; common fine pores; strongly effervescent, 12 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); gradual smooth boundary. (10 to 16 inches thick)
Bkg--15 to 28 inches; gray (2.5Y 6/1) silty clay loam, dark gray (2.5Y 4/1) moist; massive; hard, firm, moderately sticky and moderately plastic; many fine and few medium roots; many fine and medium pores; violently effervescent, 45 percent calcium carbonate equivalent; moderately alkaline (pH 8.4); clear smooth boundary. (5 to 45 inches thick)
Cg1--28 to 47 inches; light gray (5Y 7/1) silty clay loam, gray (5Y 6/1) moist; massive; extremely hard, very firm, very sticky and very plastic; few fine and medium roots; common fine pores; violently effervescent, 34 percent calcium carbonate equivalent; strongly alkaline (pH 8.8); gradual wavy boundary. (0 to 37 inches thick)
Cg2--47 to 62 inches; light gray (5Y 7/1) silty clay loam, gray (5Y 6/1) moist, common medium distinct, grayish brown (10YR 5/2) redoximorphic depletions; massive; extremely hard, very firm, very sticky and very plastic; few fine and medium roots; common fine pores; violently , 24 percent calcium carbonate equivalent; strongly alkaline (pH 8.8); gradual wavy boundary.
TYPE LOCATION: Cache County, Utah: one mile south and 1 mile east of Mendon Post Office, 1,100 feet south and 500 feet east of the northwest corner of the northeast 1/4, sec. 12, T. 11 N., R. 1 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 47 to 52 degrees F.
The particle-size control section ranges from 25 to 35 percent clay with textures of silt loam or silty clay loam. The Logan soils are generally free from salts and alkali, but are moderately affected in some areas. Depth to a seasonal high water table is from the soil surface to 20 inches. The calcium carbonate equivalent averages from 15 to 40 percent in the particle-size control section. Electrical conductivity of the saturation extract is 0 to 4 throughout. Thickness of the mollic epipedon and depth to calcic horizon is 10 to 25 inches. Reaction is moderately alkaline or strongly alkaline.
The Oe horizon where present is peaty in places and ranges to 12 inches thick.
The A horizon has hue of 10YR or 2.5Y, values of 3 to 5 dry, 2 or 3 moist and chroma of 1 or 2. Texture is silt loam or silty clay loam. Clay content is 18 to 35 percent. Organic matter content is most commonly 6 to 10 percent but ranges from 4 to 20 percent. The calcium carbonate equivalent ranges from 3 to 25 percent.
The Bkg horizon has hues of 2.5Y, 5Y, 5GY or neutral, value of 5 to 8 dry, 4 to 7 moist and chroma of 1 or less. Structure is lacking to weak subangular blocky or is weak to moderate prismatic parting to angular blocky. It is weakly cemented in places. The consistence is friable or firm moist and slightly hard or hard dry. The calcium carbonate equivalent is 15 to 60 percent. Textures are silt loam and silty clay loam. Reaction is moderately or strongly alkaline. Some pedons have organic stains on faces of peds and lining pores. Carbonates are in nodules, soft masses or are disseminated.
The Cg horizon has hues of 2.5Y, 5Y or neutral, value of 5 to 8 dry, 4 to 7 moist and chroma of less than 2 where the soil is not mottled. The lower C horizon consists of stratified coarse to fine textured mixed lacustrine sediments and alluvium. Textures are silt loam, silty clay loam, silty clay and fine sandy loam. Structure is massive or prismatic parting to angular blocky. Consistence is hard to extremely hard dry and firm to very firm moist. Some pedons have carbonates as fine filaments.
COMPETING SERIES: These are the Chipman(UT), Harpster(IL), Prophetstown(IL) and Provo Bay(UT) series. The Chipman soils have a dominant hue of 10YR above 30 inches. Harpster soils have a mean annual soil temperature of 53 to 57 degrees F. and receive more than 32 inches of precipitation. Prophetstown soils have 18 to 27 percent clay in the control section and receive more than 32 inches of precipitation. The Provo Bay soils have more than 40 percent carbonates in the particle-size control section.
GEOGRAPHIC SETTING: The Logan soils are on smooth to undulating stream terraces, lake terraces, and flood plains. Slopes are 0 to 3 percent. These soils have formed in moderately fine textured alluvium and reworked lake sediments from many kinds of rocks, but dominantly from quartzite, sandstone, limestone and gneiss. The climate is dry subhumid or dry semi-arid in Nevada. The average annual precipitation is 8 to 18 inches. Elevation ranges from 4,200 to 6,100 feet. The mean annual air temperature is 45 to 51 degrees F, the average summer temperature is 65 to 73 degrees F, and the freeze-free period is 90 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Airport, Bramwell, Cudahy, Ironton, Kirkham, Roshe Springs, and Woods Cross soils. Airport soils have horizons of clay accumulation that are high in exchangeable sodium. Bramwell and Kirkham soils are somewhat poorly drained and Bramwell lacks a mollic epipedon. Cudahy soils have a petrocalcic horizon. Ironton soils have a mollic epipedon more than 16 inches thick and are in a coarse loamy family. Roshe Springs soils have more than 40 percent carbonates in the particle-size control section. Woods Cross soils are noncalcareous throughout.
DRAINAGE AND PERMEABILITY: Poorly and very poorly drained; negligible to low runoff; permeability is dominantly very slow but it ranges to moderately slow.
USE AND VEGETATION: Used for meadow hay and pasture. The native vegetation is mainly saltgrass, rushes, bluegrass, and meadow foxtail.
DISTRIBUTION AND EXTENT: Central and northern Utah, southern Idaho, and northeastern Nevada. MLRA 28A. The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cache County (Cache Valley Area), Utah, 1913.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone of dark colored soil material from the surface of the mineral soil to a depth of 15 inches. (A horizon)
Calcic horizon - the zone of calcium carbonate accumulation from a depth of 15 inches to a depth of 28 inches. (Bkg horizon)
Particle-size control section - the zone from 10 to 40 inches.
The classification is based on the "Keys to Soil Taxonomy, Eighth Edition, 1998". Superactive cation exchange activity class is based on NSSL data.