LOCATION GRASSYHOLLOW WY
Tentative Series
Rev. TAG-DMM-RJS
05/2011
GRASSYHOLLOW SERIES
The Grassyhollow series consists of moderately deep, well drained soils that formed in slope alluvium or colluvium over residuum weathered from conglomerate. These soils are on escarpments and mountain slopes. Slopes are 15 to 50 percent. Mean annual precipitation is about 430 mm, and mean annual air temperature is about 1 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Calcic Argicryolls
TYPICAL PEDON: Grassyhollow very gravelly loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 8 cm; reddish brown (5YR 4/3) very gravelly loam, dark reddish brown (5YR 3/3) moist; moderate fine subangular blocky structure; soft, friable, nonsticky and nonplastic; many fine roots; many fine interstitial pores; 35 percent gravel and 2 percent cobbles; finely disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (6 to 15 cm thick)
Btk1--8 to 32 cm; reddish brown (5YR 4/3) very gravelly loam, dark reddish brown (5YR 3/3) moist; moderate medium subangular blocky structure; moderately hard, firm, slightly sticky and slightly plastic; many fine roots; many fine tubular pores; 5 percent faint clay films on all faces of peds; 35 percent gravel and 2 percent cobbles; 25 percent calcium carbonate masses on bottom of rock fragments and finely disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (15 to 30 cm thick)
Btk2--32 to 54 cm; red (2.5YR 4/6) very gravelly clay loam, dark red (2.5YR 3/6) moist; moderate medium subangular blocky structure; moderately hard, firm, slightly sticky and slightly plastic; few very fine roots; many fine tubular pores; 5 percent faint clay films on all faces of peds; 40 percent gravel and 5 percent cobbles; 10 percent calcium carbonate masses throughout and 20 percent calcium carbonate masses on bottom of rock fragments; violently effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (15 to 30 cm thick)
R--54 cm; strongly cemented conglomerate bedrock.
TYPE LOCATION: Sublette County, Wyoming; located approximately 1,450 feet south and 595 feet east from the northwest corner of the section of section 26, T. 27N, R. 114W; USGS The Hogsback, Wyoming topographic quadrangle; 42 degrees 18 minutes 5.00 seconds north latitude and 110 degrees 21 minutes 45.00 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil temperature - 1.5 to 3.5 degrees C.
Mollic epipedon thickness - 25 to 40 cm
Depth to argillic horizon - 8 to 13 cm
Depth to calcic horizon - 25 to 40 cm
Depth to lithic contact - 50 to 100 cm
Particle-size control section (weighted average) - greater than 35 percent rock fragments
A horizon
Hue: 2.5YR or 5YR; dry or moist
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Clay content: 15 to 25 percent
Rock Fragments: 35 to 45 percent--30 to 45 percent gravel, 0 to 5 percent cobbles
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
Btk1 horizon
Hue: 2.5YR or 5YR; dry or moist
Value: 3 or 4; dry
Texture: clay loam, loam
Clay content: 20 to 30 percent
Rock Fragments: 35 to 50 percent--30 to 45 percent gravel, 0 to 5 percent cobbles
Calcium carbonate equivalent: 10 to 15 percent
Reaction: pH 7.9 to 8.4
Btk2 horizon
Hue: 2.5YR or 5YR; dry or moist
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 4 or 6; dry or moist
Clay content: 30 to 38 percent
Carbonate clay content: 5 to 7 percent
Rock Fragments: 35 to 55 percent--30 to 50 percent gravel, 0 to 10 percent cobbles
Calcium carbonate equivalent: 20 to 25 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Brodie (WY) - have a paralithic contact at depths of 150 to 200 cm
Cavemountain (NV) - have a xeric soil moisture regime
Daisypeak (MT) - do not have hues of 2.5YR or 5YR
Hodden (CO) - are very deep
Hoodling (CO) - are very deep
Latigo (ID) - are very deep
Maciver (MT) - are very deep
Nurkey (ID) - are very deep
Teeler (WY) - are very deep
Wilhelm (WY) - are very deep
GEOGRAPHIC SETTING:
Landform - escarpments, mountain slopes
Elevation - 2375 to 2565 meters
Slope - 15 to 50 percent
Parent Material - slope alluvium or colluvium over residuum weathered from conglomerate
Climate - long, cold winters; cool, moist springs; short, cool summers.
Mean annual precipitation - 380 to 485 mm with peak periods of precipitation occurring during the spring
Mean annual air temperature - 0.5 to 2.0 degrees C.
Frost-free period - 25 to 45 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Grassyhollow soils are primarily used for rangeland. The potential native vegetation is mainly mountain big sagebrush, Idaho fescue, spike fescue, bluebunch wheatgrass, and antelope bitterbrush.
DISTRIBUTION AND EXTENT: Grassyhollow soils are of small extent in southwestern Wyoming. MLRA - 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES PROPOSED: Sublette County, Wyoming, 2011. The series name is derived from a local landmark.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 32 cm (A, Btk1 horizons)
Argillic horizon - 8 to 54 cm (Btk1, Btk2 horizons)
Calcic horizon - from 32 to 54 cm (Btk2 horizon)
Lithic contact - at 54 cm (R horizon)
Particle-size control section - from 8 to 54 cm (Btk1, Btk2 horizons)
Grassyhollow soils have a cryic temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.