LOCATION BRISLAWN WYEstablished Series
TAXONOMIC CLASS: fine, smectitic, mesic Aridic Paleustalfs
TYPICAL PEDON: Brislawn loam - on a north facing slope of 1 percent, in native rangeland. (Colors are for dry soil unless otherwise stated)
E--0 to 6 inches; brown (7.5YR 5/3) loam, dark brown (7.5YR 3/3) moist; weak thin platy structure parting to weak fine granular; soft, friable, slightly sticky and slightly plastic; common very fine and fine roots throughout; common fine pores; 2 percent subangular porcelanite channers; neutral; (pH 6.6); abrupt smooth boundary. (2 to 6 inches thick)
Bt1--6 to 14 inches; reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; strong medium and coarse prismatic structure parting to strong fine and medium angular blocky; hard, firm, very sticky and very plastic; common very fine and fine roots throughout; common fine pore; many distinct discontinuous dark reddish brown (5YR 3/3) clay films on faces of peds; 5 percent subangular porcelanite channers; neutral; (pH 7.2); clear wavy boundary.
Bt2--14 to 21 inches; brown (7.5YR 4/3) clay, dark brown (7.5YR 3/3) moist; strong medium and coarse prismatic structure parting to moderate fine and medium blocky; hard, firm, very sticky and very plastic; common very fine and fine roots throughout; common fine pores; many distinct discontinuous dark brown (7.5YR 3/2) clay films on faces of peds; 5 percent subangular poecelanite channers; slightly alkaline; (pH 7.6); clear wavy boundary. (Combined Bt horizons 8 to 20 inches thick)
2Btk--21 to 31 inches; brown (7.5YR 4/4) channery clay loam, dark brown (7.5YR 3/4) moist; moderate fine and medium angular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine and fine roots throughout; common fine pores; common distinct discontinuous dark brown (7.5YR 3/3) clay films on faces of peds; few fine irregular light gray (10YR 7/2) carbonate threads throughout; 15 percent subangular porcelanite channers; strongly effervescent; moderately alkaline; (pH 8.0); gradual wavy boundary. (0 to 10 inches thick)
2Bk--31 to 37 inches; brown (7.5YR 5/4) very channery clay loam, brown (7.5YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine and fine roots throughout; few fine pores; few distinct discontinuous light gray (10YR 7/2) carbonate coats on bottom surfaces of rock fragments; few fine irregular light gray (10YR 7/2) carbonate threads; carbonates disseminated throughout; strongly effervescent; 40 percent subangular porcelanite channers; moderately alkaline; (pH 8.2); clear wavy boundary. (6 to 19 inches thick)
3C--37 to 60 inches; fractured porcelanite with 8 percent interstices or voids filled with light brown (7.5YR 6/4) sandy loam, brown (7.5YR 5/4) moist; common distinct discontinuous light gray (10YR 7/2) carbonate coats on bottom surfaces of rock fragments; slightly effervescent, fine earth material has variable effervescence; 70 percent subangular porcelanite channers, 17 percent subangular flagstones and 5 percent subrounded stones; slightly alkaline.
TYPE LOCATION: Campbell County, Wyoming; about 1100 feet east and 400 feet south of the northwest corner of Sec. 18, T 56 N, R 71 W.; USGS Rocky Butte SW, WY topographic quadrangle; lat. 44 degrees 50 minutes 35 seconds N. and long. 105 degrees 26 minutes 56 seconds W.
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon ranges from 14 to 31 inches. Depth to continuous accumulations of carbonates ranges from 15 to 28 inches. Depth to fragmental material is 20 to 40 inches.
E horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6, 3 or 4 moist
Chroma: 3 or 4
Texture: loam, very fine sandy loam or fine sandy loam
Clay content: 10 to 20 percent
Rock fragments: 0 to 14 percent
Reaction: slight acid or neutral
Bt horizon:
Hue: 5YR, 7.5YR or 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 or 4
Textures: clay or clay loam
Clay content: 35 to 50 percent
Rock fragments: 0 to 14 percent porcelanite channers
Reaction: neutral or slightly alkaline.
2Btk horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6, 3 to 6 moist
Chroma: 3 or 4
Textures: clay or clay loam
Clay content: 35 to 50 percent
Rock fragments: 15 to 50 percent porcelanite channers
Reaction: slightly alkaline or moderately alkaline.
Calcium carbonate equivalent: 3 to 12 percent.
2Bk horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6, 3 to 6 moist
Chroma: 3 or 4
Textures: loam or clay loam
Clay content: 15 to 35 percent clay
Rock fragments: 25 to 65 percent porcelanite channers, and 0 to 10 percent flagstones
Reaction: moderately alkaline or strongly alkaline.
Calcium carbonate equivalent: 3 to 12 percent
3C horizon:
Hue: 2.5YR, 5YR or 7.5YR
Value: 5 or 6, 4 or 5 moist
Chroma: 3 to 4
Textures: fractured porcelanite with less than 10 percent of interstices or voids filled with loam, sandy loam or loamy sand
Rock fragments: 70 to 95 percent channers, 0 to 15 percent flagstones, and 0 to 5 percent stones
Reaction: slightly acid to slightly alkaline.
COMPETING SERIES: These are the Bleumont, Jaywest and Spottedhorse series. These soils do not have fragmental material within depths of 40 inches.
GEOGRAPHIC SETTING: Brislawn soils are on fans remnants, terraces, broad ridges and plateaus. They formed in alluvium or eolian deposits over weathered porcelanite or very channery slopewash derived from porcelanite. Slopes are 0 to 15 percent. Elevations are 3,800 to 5,300 feet. The mean annual precipitation ranges from 15 to 17 inches, half of which falls as rain or snow from late March through June. The mean annual air temperature ranges from 46 to 50 degrees F. The frost-free season is about 105 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Deekay, Ironbutte, Moorhead and Muleherder soils. Deekay soils are fine-loamy and do not have fragmental material within depths of 40 inches. Ironbutte soils do not have argillic horizons and are shallow to fragmental material consisting of porcelanite. Moorhead soils are fine and do not have fragmental material within depths of 40 inches. Muleherder soils do not have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; runoff is negligible to high depending on slope; moderately slow or slow over rapid permeability.
USE AND VEGETATION: These soils are utilized for rangeland and wildlife habitat. The native vegetation is mainly western wheatgrass, needleandthread, blue grama and green needlegrass.
DISTRIBUTION AND EXTENT: Northeastern Wyoming. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado.
SERIES ESTABLISHED: Campbell County, Wyoming, Southern Part; 2001.
REMARKS: Diagnostic horizons and features recognized in this pedon are: Ochric epipedon - the zone from the surface of the soil to a depth of 6 inches (E horizon); Argillic horizon - the zone from 6 to 31 inches (Bt1, Bt2 and 2Btk horizons); particle size control section - the zone from 6 to 26 inches (Bt1, Bt2 and 2Btk horizons); Paleustalf great group criteria - An absolute increase in clay of more than 15 percent within a vertical distance of 1 inch at the upper boundary of the Bt horizon.
LRR- G
The Brislawn series have previously been correlated as a moist phase of the Lawver series.