LOCATION SNILLOC WYEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Aridic Calciustepts
TYPICAL PEDON: Snilloc very fine sandy loam -- on a north facing slope of one percent, in a cultivated field. (Colors are for dry soil unless otherwise stated.)
Ap1--0 to 5 (0 to 2 inches); pale brown (10YR 6/3) very fine sandy loam, brown (10YR 4/3) moist; moderate very fine and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and few fine continuous irregularly shaped pores; violently effervescent; calcium carbonate disseminated; moderately alkaline (pH 8.2); abrupt smooth boundary.
Ap2--5 to 20 centimeters (2 to 8 inches); pale brown (10YR 6/3) very fine sandy loam, brown (10YR 4/3) moist; weak medium and coarse subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and few fine continuous irregularly shaped pores; violently effervescent; calcium carbonate disseminated; moderately alkaline (pH 8.2); abrupt smooth boundary. (Combined thickness of the A horizon is 13 to 30 centimeters (5 to 12 inches) thick)
Bk1--20 to 43 centimeters (8 to 17 inches); very pale brown (10YR 7/3) loam, yellowish brown (10YR 5/4) moist; weak very coarse prismatic structure; very hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; few very fine and fine continuous irregularly shaped pores; 16 percent calcium carbonate equivalent; violently effervescent; calcium carbonate disseminated and as few soft masses and seams; moderately alkaline (pH 8.2); gradual wavy boundary.
Bk2--43 to 76 centimeters (17 to 30 inches); very pale brown (10YR 8/2) loam, very pale brown (10YR 7/4) moist; massive; hard, very friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine and fine continuous irregularly shaped pores; 39 percent calcium carbonate equivalent; 5 percent gravel; violently effervescent; calcium carbonate disseminated and as common soft masses and seams; strongly alkaline (pH 8.6); gradual wavy boundary.
Bk3--76 to 152 centimeters (30 to 60 inches); very pale brown (10YR 8/3) sandy loam, light yellowish brown (10YR 6/4) moist; massive; hard, very friable, slightly sticky and nonplastic; few very fine and fine roots; common very fine and fine continuous irregularly shaped pores; 25 percent calcium carbonate equivalent; 5 percent gravel; violently effervescent; calcium carbonate disseminated and as common soft masses and seams; strongly alkaline (pH 8.6). (Combined Bk horizon is 25 to 127 centimeters (10 to 50 inches) thick)
TYPE LOCATION: Platte County, Wyoming; 1.6 kilometers (1 mile) north of Chugwater, about 198 meters (650 feet) west and 610 meters (2000 feet) north of the southeast corner of Section 24, T. 21 N., R. 67 W. 41 degrees 46 minutes and 32 seconds north latitude and 104 degrees 49 minutes 46 seconds west longitude.
RANGE IN CHARACTERISTICS:
Rock fragments: typically 0 to 20 percent throughout the profile
Calcic horizon: 5 to 40 percent calcium carbonate equivalent
Depth to the calcic horizon: less than 51 centimeters (20 inches)
Moisture control section: dry more than half the time cumulative that the soil temperature at a depth of 51 centimeters (20 inches) is 5 degrees C. (41 degrees F.) or warmer, but is dry at least 60 consecutive days from July 1 to October 15 and for 90 cumulative days during this period
Mean annual soil temperature: 8 to 11 degrees C. (47 to 51 degrees F.)
A horizon:
Hue: 10YR or 7.5YR:
Value: 5 or 6, and 3 to 5 moist
Chroma: 2 to 4
Textures: fine sandy loam or very fine sandy loam
Reaction: slightly alkaline or moderately alkaline
Bk horizon:
Hue: 10YR or 7.5YR
Value: 5 to 8, and 4 to 7 moist
Chroma: 2 to 4
Textures: commonly loam or fine sandy loam and include sandy loam or very fine sandy loam
Reaction: moderately or strongly alkaline
Calcium carbonate equivalent: 5 to 40 percent and decreases with depth
Coarse fragments: 0 to 20 percent
C horizon: (when present)
Hue: 10YR or 7.5YR
Value: 6 or 7, and 5 or 6 moist
Chroma: 3 or 4
Texture: sandy loam, or fine sandy loam
Coarse fragments: 0 to 20 percent
COMPETING SERIES: These are the
Sweatbee and
Tanoan series.
The Sweatbee soils have more than 15 percent rock fragments in the particle size control section.
Tanoan soils have a calcic horizon at 5 to 10 centimeters (2 to 4 inches).
GEOGRAPHIC SETTING:
Landform: structural benches, terraces, and hillslopes
Parent material: alluvium and eolian deposits derived from mixed sources
Slopes: 0 to 6 percent
Elevations: 1311 to 1737 meters (4300 to 5700 feet)
Mean annual precipitation: 30 to 38 centimeters (12 to 15 inches)
Mean annual temperature: 8 to 12 degrees C. (46 to 53 degrees F.)
Frost-free season: 110 to 130 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Chugcity,
Clapper,
Keeline, and
Recluse soils.
Chugcity soils have bedrock between 51 to 102 centimeters (20 and 40 inches)
Clapper soils have a particle-size control section that averages more than 35 percent rock fragments.
Keeline soils lack a calcic horizon.
Recluse soils have a mollic epipedon, an argillic horizon and have a fine-loamy particle-size control section.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: well drained
Runoff: slow to medium
Saturated Hydraulic Conductivity: very high
USE AND VEGETATION: These soils are utilized for grazing by domestic livestock, wildlife habitat, and for dry-fallow and irrigated cropland and hayland.
The native vegetation is needleandthread, prairie sandreed, western wheatgrass, blue grama, prairie junegrass, threadleaf sedge, and silver sagebrush.
Wheat, oats, alfalfa, and short season corn are the principle crops grown under cultivation.
DISTRIBUTION AND EXTENT: Snilloc soils occur in eastern Wyoming. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Platte County, Wyoming, 1989.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 41 centimeters (0 to 8 inches) (Ap1,Ap2)
Calcic horizon: 20 to 152 centimeters (8 to 60 inches) (Bk1,Bk2,Bk3)
SIR- WY1016
LRR=G
Modified format by LRM in 3/2006 to include metric conversion and change permeability to saturated hydraulic conductivity.