LOCATION CORDER ID

Established Series
Rev. DJT/ALH/RWL
07/2012

CORDER SERIES

The Corder series consists of shallow to a duripan, well drained soils with moderate permeability that formed in loess and weathered volcanic ash mixed with colluvium from basalt. Slopes range from 0 to 25 percent on plains. The average annual precipitation is about 7 inches and the average annual temperature is about 53 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Typic Argidurids

TYPICAL PEDON: Corder silt loam -- on a nearly level lava flow lobe, at 3,200 feet elevation in rangeland. When described on May 13, 1999, the soil was dry throughout. (Colors are for air-dry soil unless otherwise noted.)

A1--0 to 2 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many very fine irregular pores; 5 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.4); clear smooth boundary.

A2--2 to 4 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak thin and very fine platy structure; soft, very friable, slightly sticky and slightly plastic; common very fine, few fine and medium roots; many very fine, few fine tubular pores; slightly alkaline (pH 7.5); clear wavy boundary. (combined A horizon - 2 to 7 inches thick)

Bt--4 to 11 inches; brown (10YR 5/3) silt loam, brown (10YR 4/3) moist; moderate coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine, few fine and medium roots; common very fine, fine and medium tubular pores; common faint clay films on faces of peds and in pores; slightly alkaline (pH 7.6); clear smooth boundary. (5 to 10 inches thick)

Bkq--11 to 16 inches; pale brown (10YR 6/3) gravelly silt loam, brown (10YR 4/3) moist; slightly hard, friable, slightly sticky and nonplastic; few very fine, fine and medium roots; few very fine tubular pores; 10 percent gravel and 5 percent cobbles coated with calcium carbonates and silica; violently effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary. (3 to 10 inches thick)

Bkqm--16 to 24 inches; very pale brown (10YR 7/3) continuous indurated siliceous laminae 2 to 4 mm thick over light gray (10YR 7/2) very strongly cemented duripan, light brownish gray (10YR 6/2) moist; massive; 40 percent rock fragments; violently effervescent; clear wavy boundary. (2 to 10 inches thick)

2R--24 inches; basalt.

TYPE LOCATION: Ada County, Idaho; about 15 miles northwest of Grandview; 1,000 feet north and 400 feet east of the southwest corner of section 3, T.2 S., R.3 E.; USGS Big Foot Butte Quadrangle; (Latitude - 47 degrees, 11 minutes, 16 seconds N. and Longitude - 116 degrees, 12 minutes, 49 seconds W.).

RANGE IN CHARACTERISTICS:
Average annual soil temperature - 53 to 56 degrees F.
Depth to duripan - 10 to 20 inches
Depth to bedrock - 20 to 30 inches
Depth to calcium carbonate - 10 to 15 inches
Particle-size control section - 18 to 27 percent clay; 5 to 35 percent rock fragments
Volcanic glass - 5 to 15 percent
Acid oxalate extract Al + 1/2 Fe - less than 0.2 percent
Moisture control section - dry for more than 180 days when the soil temperature is greater than 41 degrees F.

A horizon
Value - 5 or 6 dry, 4 or 5 moist
Clay content - 10 to 18 percent
Rock fragments - 0 to 5 percent stones, 0 to 15 percent cobbles, 0 to 20 percent gravel and 0 to 35 percent total
Reaction - neutral or slightly alkaline

Bt horizon
Value - 5 through 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Clay content - 18 to 27 percent
Rock fragments - 0 to 5 percent stones, 0 to 10 percent cobbles, 0 to 20 percent gravel and 0 to 35 percent total
Reaction - slightly alkaline or moderately alkaline

Bkq horizon
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - SIL, L or VFSL
Clay content - 10 to 18 percent
Calcium carbonate content - 10 to 15 percent
Rock fragments - 0 to 5 percent stones, 0 to 10 percent cobbles, 10 to 40 percent gravel and 10 to 45 percent total
Reaction - slightly alkaline or moderately alkaline

COMPETING SERIES: These are the Cleaver, Dobel, Laped, Shoofly, Silent, Spanel and Tumtum series. The Cleaver, Dobel, Shoofly, Silent, Spanel and Tumtum soils do not have a lithic contact within 60 inches. The Laped soils have soil temperatures of 47 to 52 F. and have particle-size control sections that contain 27 to 35 percent clay.

GEOGRAPHIC SETTING: Corder soils are on plug domes, lava flow lobes, pressure ridges and tumuli on shield volcanoes of plains. Elevations are 2,800 to 3,550 feet. Slopes range from 0 to 25 percent. These soils formed in loess and weathered volcanic ash mixed with colluvium from basalt. Average annual precipitation is 6 to 8 inches. Average annual temperature is 51 to 54 degrees F. Frost-free period is 130 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chattin, Strike, and Tadpole soils. Chattin, Strike and Tadpole soils are very deep to bedrock. Landscape positions are similar.

DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; moderate permeability.

USE AND VEGETATION: Corder soils are used mainly for rangeland. Natural vegetation is shadscale saltbush, bud sagebrush, Indian ricegrass and Thurber needlegrass.

DISTRIBUTION AND EXTENT: Ada and Elmore Counties, Idaho. MLRA 11. These soils are of limited extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Ada County, Idaho, 2012.

REMARKS: Diagnostic horizons and features recognized in this pedon:

Ochric epipedon - zone from the surface to 4 inches (A1 and A2 horizons)

Argillic horizon - zone from 4 to 11 inches (Bt horizon)

Particle-size control section - zone from 4 to 11 inches

Soil moisture regime - aridic

National Cooperative Soil Survey
U.S.A.