LOCATION LAWVER WYEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Ustic Paleargids
TYPICAL PEDON: Lawver loam -- on a northwest facing slope of 4 percent, utilized as rangeland. (Colors are for dry soil unless otherwise stated)
E--0 to 4 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak thick platy structure parting to weak fine and medium granular; soft, very friable, nonsticky and nonplastic; many very fine and fine roots throughout; 5 percent angular porcelanite channers; neutral; abrupt smooth boundary. (2 to 6 inches thick)
Bt1--4 to 10 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; moderate medium prismatic structure parting to strong fine and medium subangular blocky; hard, friable, moderately sticky and moderately plastic; many very fine and fine roots throughout; few distinct discontinuous dark brown (10YR 3/3) clay films on faces of peds; 5 percent angular porcelanite channers; neutral; clear smooth boundary.
Bt2--10 to 20 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; strong fine and medium prismatic structure parting to strong fine and medium angular blocky; hard, firm, moderately sticky and moderately plastic; many very fine and fine roots throughout; few distinct discontinuous dark brown (10YR 3/3) clay films on faces of peds; 8 percent angular porcelanite channers; neutral; clear wavy boundary. (Combined Bt horizons 8 to 20 inches thick)
Btk--20 to 27 inches; pinkish gray (7.5YR 6/2) channery clay loam, brown (7.5YR 5/4) moist; strong fine and medium angular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine and fine roots throughout; few distinct discontinuous dark brown (7.5YR 3/4) clay films on faces of peds; strongly effervescent; carbonates are disseminated throughout; 20 percent angular porcelanite channers; slightly alkaline; gradual wavy boundary. (0 to 7 inches thick)
Bk--27 to 38 inches; light brown (7.5YR 6/4) very channery clay loam, brown (7.5YR 5/4) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots throughout; strongly effervescent; carbonates are disseminated throughout; 40 percent angular porcelanite channers and 10 percent subrounded mixed cobbles; strongly alkaline; clear wavy boundary. (6 to 19 inches thick)
2C--38 to 60 inches; fractured porcelanite with 8 percent partly filled interstices of light reddish brown (2.5YR 6/4) sandy loam, reddish brown (2.5YR 4/4) moist; massive; soft, friable, nonsticky and nonplastic; common fine roots throughout; soil matrix is noneffervescent but thin coatings of carbonate occur on some rock fragments; 65 percent angular porcelanite channers and 20 percent subangular mixed flagstones and 7 percent subrounded mixed stones; neutral.
TYPE LOCATION: Campbell County, Wyoming; about 50 feet south and 1,900 feet east of the northwest corner of section 14, T. 43 N., R. 69 W. 43 degrees 42 minutes 33 seconds north latitude and 105 degrees 6 minutes 51 seconds west longitude.
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon ranges from 16 to 27 inches. Depth to continuous accumulations of calcium carbonate ranges from 12 to 22 inches. Depth to material with more than 50 percent porcelanite ranges from 20 to 40 inches. The soil is dry in the moisture control section more than half the time cumulative that the soil temperature at a depth of 20 inches is 41 degrees F., which occurs about April 22-28, and is dry in all parts of the moisture control section for at least 60 consecutive days between July 1 and October 25 and for at least 90 cumulative days during this period. The mean annual soil temperature is 47 to 51 degrees F., and the soil temperature at a depth of 20 inches is 41 degrees F. or more for 175 to 192 days.
The A horizon has hue of 7.5YR or 10YR, value of 4 to 6 dry and 3 or 4 moist, and chroma of 3 or 4.
The Bt horizon has hue of 7.5YR or 10YR, value of 5 or 6 dry and 4 or 5 moist, and chroma of 3 or 4. Textures are clay loam or clay with 35 to 50 percent clay. It averages 5 to 15 percent porcelanite channers, but some subhorizons may have up to 25 percent channers. It is neutral or slightly alkaline.
The Btk horizon has hue of 7.5YR or 10YR, value of 6 or 7 dry and 5 or 6 moist, and chroma of 2 to 4. Textures are clay loam or clay with 35 to 45 percent clay, and are modified by 5 to 25 percent porcelanite channers. Calcium carbonate equivalent ranges from 4 to 12 percent. It is slightly alkaline or moderately alkaline.
The Bk horizon has hue of 7.5YR or 10YR, value of 6 or 7 dry and 5 or 6 moist, and chroma of 3 or 4. Textures are typically very channery loam or very channery clay loam, but may include channery loam or channery clay loam. It has 25 to 35 percent clay, 20 to 50 percent porcelanite channers, and 0 to 10 percent cobbles. Calcium carbonate equivalent ranges from 4 to 12 percent. It is moderately alkaline or strongly alkaline.
The 2C horizon has hue of 2.5YR or 5YR, value of 5 or 6 dry and 4 or 5 moist, and chroma of 2 to 4. The fine-earth fraction typically is sandy loam. The horizon has 50 to 95 percent porcelanite fragments, of which 50 to 65 percent are channers, 10 to 20 percent cobbles, and 0 to 10 percent stones. It is slightly acid to slightly alkaline.
COMPETING SERIES: These are the Bidman, Big Horn, Briggsdale, Gibbler, Mughut and Parmleed series. Bidman and Big Horn soils do not have horizons with more than 50 percent porcelanite fragments within a depth of 40 inches. Briggsdale, Gibbler, Mughut and Parmleed soils have bedrock within depths of 40 inches.
GEOGRAPHIC SETTING: Lawver soils are on structural fans, terraces, broad ridges, and on mesas. They formed in alluvium or loess 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 10 to 17 inches, half of which falls as rain or snow from late March through June. The mean annual air temperature ranges from 44 to 50 degrees F. The frost-free season is about 105 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Teckla and Wibaux soils. Teckla soils are fine-loamy. Wibaux soils are loamy-skeletal over fragmental and lack argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; low to medium runoff; moderately slow to 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: Lawver soils occur in northeast Wyoming. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Campbell County, Wyoming, Southern Part; 1995.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 4 inches (A)
Argillic horizon - 4 to 27 inches (Bt1, Bt2, Btk)
An absolute increase in clay of greater than 15 percent within a vertical distance of 1 inch at the upper boundary of the Bt horizon.
SIR- WY1283
LRR- G