LOCATION LONGBARN ORTentative Series
TAXONOMIC CLASS: fine, smectitic, frigid Vertic Palexerolls
TYPICAL PEDON: Longbarn very cobbly ashy loam, on a 15 percent slope, rangeland. (Colors are for moist soils unless otherwise noted.)
A1--0 to 2 inches; very dark grayish brown (10YR 3/2) very cobbly ashy loam, grayish brown (10YR 5/2) dry; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine interstitial pores; 20 percent gravel and 20 percent cobbles; neutral (pH 6.8); clear wavy boundary.
A2--2 to 6 inches; very dark grayish brown (10YR 3/2) very gravelly ashy sandy loam, grayish brown (10YR 5/2) dry; weak very fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine interstitial pores; 30 percent gravel and 15 percent cobbles; neutral (pH 7.0) clear wavy boundary. (Combined thickness of the A horizon is 3 or 7 inches thick)
2AB--6 to 11 inches; dark brown (10YR 3/3) very cobbly clay loam, dark grayish brown (10YR 4/2) dry; moderate very fine subangular blocky structure; slightly hard, friable, very sticky and moderately plastic; few very fine and fine roots; common very fine tubular pores; 20 percent gravel and 20 percent cobbles; neutral (pH 7.2); abrupt wavy boundary. (4 to 7 inches thick)
2Bt1--11 to 16 inches; dark brown (7.5YR 3/3) cobbly clay, brown (7.5YR 5/3) dry; strong fine prismatic structure parting to strong medium subangular blocky; extremely hard, extremely firm, very sticky and very plastic; few medium roots; common fine tubular pores; many prominent continuous clay films on faces of peds and in pores; 3/8 inch vertical cracks in matrix; 10 percent gravel and 10 percent cobbles; neutral (pH 7.2); clear wavy boundary. (4 to 8 inches thick)
2Bt2--16 to 26 inches; brown (7.5YR 4/3) cobbly clay, brown (7.5YR 5/4) dry; moderate fine subangular blocky structure; very hard, very firm, moderately sticky and very plastic; few fine roots; few very fine tubular pores; common distinct discontinuous clay films on faces of peds; 1/4 inch vertical cracks in matrix; 10 percent gravel and 10 percent cobbles; neutral (pH 7.2); clear wavy boundary. (8 to 12 inches thick)
2Bt3--26 to 38 inches; brown (7.5YR 4/4) cobbly clay loam, strong brown (7.5YR 5/6) dry; weak very fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few faint discontinuous clay films on faces of peds; 10 percent gravel and 20 percent cobbles; neutral (pH 7.2); clear wavy boundary. (10 to 14 inches thick)
3C--38 to 51 inches; dark yellowish brown (10YR 4/4) gravelly sandy loam, yellowish brown (10YR 5/6) dry; massive; soft, very friable, nonsticky and nonplastic; 15 percent gravel and 5 percent cobbles; neutral (pH 7.2); clear wavy boundary. (11 to 18 inches thick)
3R--51 inches; tuff
TYPE LOCATION: Crook County, Oregon; About 3 1/2 miles south of Gerry Mountain, Oregon; 1,300 feet east and 1,100 feet south of the NW corner of section 23. T.20S., R.21E. Latitude 43 degrees, 49 minutes, 30.1 seconds North; Longitude 120 degrees, 10 minutes, 20.6 seconds West, NAD 83.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in the moisture control section for 70 to 90 days following the summer solstice. The mean annual soil temperature is 42 to 47 degrees F.. Depth to lithic contact is 40 to 60 inches. The weighted average clay content of the particle-size control section is 40 to 50 percent. The weighted average rock fragment content of the particle size control section is 5 to 25 percent. The soil has a linear extensibility of 6.0 to 8.0 cm in the upper meter. There is an absolute clay increase of 15 to 25 percent between the 2AB and 2Bt horizons.
The A horizon has value of 3 or 2 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It has 5 to 30 percent glass with acid oxalate aluminum plus one-half the iron of 0.2 to 0.5.
The 2AB horizon has hue of 10YR or 7.5YR, value of 3 or 2 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It is loam or clay loam with 20 to 30 percent clay.
The 2Bt horizon has hue of 7.5YR to 2.5Y moist or dry and value of 3 or 4 moist, 5 or 6 dry and chroma of 3 or 4 moist or dry. It is clay or cly loam with 35 to 55 percent clay.
The 3C horizon has a hue of 7.5YR to 2.5Y moist or dry and value of 4 or 5 moist, 5 or 6 dry and chroma of 4 or 5 moist and 6 or 7 dry. It is loam or sandy loam.
COMPETING SERIES: These are the Booth, Campcreek, Carryback, Crowcamp, Golars, Hankins, Jesh, Joenchris, Lacrol, Tippett, Warpaint and Zumwalt series. Booth and Carryback soils are moderately deep. Campcreek soils are very deep and formed in mixed alluvium. Crowcamp soils are somewhat poorly drained. Golars soils are moderately deep and have an O horizon. Hankins soils have an O horizon and a vitrandic feature in the surface horizons. Jesh and Joenchris soils are very deep. Lacrol soils are very deep and moderately well drained. Tippett soils have a vitrandic feature in the surface horizons and are formed in loess over clayey alluvium or lacustrine deposits. Warpaint soils are very deep and have a vitrandic feature in the surface horizons. Zumwalt soils are moderately deep and have a vitrandic feature in the surface horizons.
GEOGRAPHIC SETTING: Longbarn soils are on mountain slopes at elevations of 4,000 to 5,000 feet. These soils formed in residuum from John Day Formation tuffaceous sediments and colluvium from welded tuff with an influence of volcanic ash. The climate is characterized by cool, moist winters and hot, dry summers. The mean annual precipitation is 12 to 16 inches, the mean annual temperature is 40 to 46 degrees F.,and the frost-free period is 40 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ateron, Canest, Erakatak, Ginserly, Polkbutte and Powellbutte soils. Ateron soils are lithic and are on adjacent south slopes. Canest soils are clayey-skeletal and lithic on ridges and low rolling hills. Erakatak soils are moderately deep and are on adjacent south slopes. Ginserly soils are loamy-skeletal and vitrandic on north facing slopes. Polkbutte soils are very deep and vitrandic on north facing slopes. Powellbutte soils are vitrandic and moderately deep on low rolling hills.
DRAINAGE AND PERMEABILITY: Well drained; permeability is slow.
USE AND VEGETATION: Longbarn soils are used for livestock grazing and wildlife habitat. The native vegetation is low sagebrush, Idaho fescue, bluebunch wheatgrass and Sandbergs bluegrass.
DISTRIBUTION AND EXTENT: Central Oregon; MLRA10. This series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Crook County Area, Oregon; 2005
REMARKS: Diagnostic horizons and other features in this pedon include:
Mollic epipedon - 0 to 16 inches. (A1,A2,2AB,2Bt1 horizons)
Argillic horizon - 11 to 38 inches. (2Bt1,2Bt2,2Bt3 horizons)
Pale feature - an absolute clay increase of 90 percent between the 2AB and 2Bt1 horizons.