LOCATION THENARROWS OREstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, calcareous, frigid Typic Halaquepts
TYPICAL PEDON: Thenarrows sandy loam - rangeland, on a 1 percent slope at an elevation of 4096 feet. (When described on October 7, 1994 the soil was dry 0 to 3 inches and moist to very moist 3 to 60 inches. Colors are for moist soil unless otherwise stated.)
A1--0 to 3 inches; dark gray (5Y 4/1) sandy loam, light brownish gray (2.5Y 6/2) dry; moderate coarse platy structure; hard, firm, slightly sticky and nonplastic; many very fine, fine and medium roots; common very fine and fine tubular pores; common snail shells; strongly effervescent with disseminated lime; very strongly alkaline (pH 9.2); clear smooth boundary. (1 to 4 inches thick)
A2--3 to 14 inches; dark gray (5Y 4/1); sandy loam, light brownish gray (2.5Y 6/2) dry; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine and fine, common medium roots; many very fine, fine, and medium irregular pores, common very fine tubular; strongly effervescent with disseminated lime; SAR of 24, EC of 3, CaCO3 of 10 percent; very strongly alkaline (pH 9.2); gradual wavy boundary. (7 to 14 inches thick)
A/Bw--14 to 22 inches; A material: dark grayish brown (2.5Y 4/2) loamy sand, light brownish gray (2.5Y 6/2) dry; weak medium subangular blocky structure; loose nonsticky, nonsticky; B material: light brownish gray (2.5Y 6/2) sandy loam, white (10YR 8/1) dry; weak medium subangular blocky structure; hard, friable, slightly sticky and nonplastic; common very fine and fine roots; common very fine and fine tubular pores; horizon is 50 percent A material and 50 percent B material; SAR of 19, EC of 2 CaCO3 of 21 percent; strongly effervescent with disseminated lime; very strongly alkaline (pH 9.4); clear wavy boundary. (6 to 10 inches thick)
Bw--22 to 31 inches; light brownish gray (2.5Y 6/2) sandy loam, white (10YR 8/1) dry; weak coarse and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; strongly effervescent; SAR of 19, EC of 2, CaCO3 of 17 percent; very strongly alkaline (pH 9.4); gradual wavy boundary. (9 to 27 inches thick)
Bw/C--31 to 54 inches; B material: light brownish gray (2.5Y 6/2) sandy loam, white (10YR 8/1) dry; weak medium subangular blocky structure; hard, firm and brittle, slightly plastic and nonplastic; strongly effervescent with disseminated carbonates; C material: grayish brown (10YR 5/2) loamy sand, light brownish gray (2.5Y 6/2) dry; massive; loose, nonsticky and nonplastic; strongly effervescent in spots; common very fine and fine roots; common fine and very fine tubular pores; 80 percent B material, 20 percent C material; strongly alkaline (pH 8.8); gradual wavy boundary. (15 to 25 inches thick)
C--54 to 60 inches; grayish brown (10YR 5/2) loamy sand, light brownish gray (2.5Y 6/2) dry; massive; loose, nonsticky and nonplastic; few fine roots; common very fine and fine tubular pores; 10 percent parts of B material; strongly effervescent with disseminated lime; very strongly alkaline (pH 9.5).
TYPE LOCATION: Harney County, Oregon, about 3 miles northeast of The Narrows townsite, about 700 feet east and 3300 feet south of the northwest corner section 4, T. 26 S. R 32 E. (Latitude 43 degrees 20 minutes 34 seconds N, Longitude 118 degrees 53 minutes 42 seconds W)
RANGE IN CHARACTERISTICS: The soils are ponded 6 inches deep or saturated to the surface during the months of March through June. The mean annual soil temperature is 45 to 46 degrees F. Depth to bedrock is greater than 60 inches. The particle-size control section averages 10 to 18 percent clay. Redoximorphic iron concentrations and depletions are present throughout the profile in some pedons. The soil is calcareous throughout the profile and all carbonates are disseminated.
The A horizon has a hue of 2.5Y, 5Y, or 10YR; a value of 4 through 6 dry, 3 or 4 moist. Reaction is strongly or very strongly alkaline. SAR is 13 to 25 and EC is 2 to 5.
The B horizon has a value of 6 through 8 dry, 4 through 6 moist. Reaction is strongly or very strongly alkaline. SAR is 10 to 20 and EC is 1 to 3. The percent calcium carbonate is 10 to 20 percent.
The C horizon has a value of 6 or 7 dry, 3 through 5 moist, and a chroma of 1 or 2. Reaction is moderately to very strongly alkaline. Effervescence is slightly to strongly effervescent. SAR is 2 to 5 and EC is 0 to 2.
COMPETING SERIES: No other soils are listed in this family.
GEOGRAPHIC SETTING: Thenarrows soils are on lake terraces and have slopes of 0 to 2 percent. The soils formed in lacustrine sediments. Elevations are 4090 to 4105 feet. The climate is characterized by cold, moist winters and hot, dry summers. The mean annual precipitation is 8 to 10 inches. The mean annual temperature is 43 to 45 degrees F. The frost free period is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ausmus, Duckclub and Sandgap soils. Ausmus soils are on higher lake terraces and have a natric horizon. Duckclub soils are on slightly higher terraces and are somewhat poorly drained. Sandgap soils are on sand dunes.
DRAINAGE AND PERMEABILITY: Poorly drained, ponded; moderately rapid permeability. Apparent water table is at a depth of +0.5 to 3.0 feet from March to June. Ponding is frequent and occasional.
USE AND VEGETATION: The soils are used for livestock grazing and wildlife habitat. Potential native vegetation is alkali sacaton, alkali bluegrass, and inland saltgrass.
DISTRIBUTION AND EXTENT: Lake basins of southeast Oregon; MLRA 23 and 24. Series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Harney County, Oregon, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
- Ochric epipedon
- Some pedons have a calcic horizon. The type pedon has a decrease of 4 percent (absolute) of calcium carbonate between the A/Bw and Bw horizon; thus type pedon lacks a calcic horizon, criteria 3a for calcic horizon. All carbonates are disseminated throughout the profile; thus criteria 3c3 is not met.
ADDITIONAL DATA: Reference samples S95OR-025-001; data from type location.