LOCATION GRAYSTONE WYEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Aridic Calciustolls
TYPICAL PEDON: Graystone very fine sandy loam--on a north facing slope of two percent, utilized as dry cropland.
(Colors are for dry soil unless otherwise stated.)
Ap--0 to 9 inches; brown (10YR 4/3) very fine sandy loam, dark brown (10YR 3/3) moist; strong medium and coarse clods; slightly hard, friable, slightly sticky and slightly plastic; many very fine and few fine roots; strongly effervescent; calcium carbonate disseminated; moderately alkaline (pH 8.2); abrupt smooth boundary. (7 to 10 inches thick).
Bk1--9 to 16 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; strong fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and few fine roots; violently effervescent; calcium carbonate disseminated and as few distinct soft masses, seams and streaks; 20 percent calcium carbonate equivalent; moderately alkaline (pH 8.4); gradual smooth boundary.
Bk2--16 to 44 inches; very pale brown (10YR 7/3) very fine sandy loam, brown (10YR 4/3) moist; massive; soft, friable, slightly sticky and slightly plastic; common very fine and few fine roots; violently effervescent; calcium carbonate disseminated and as few distinct soft masses, seams and streaks; 9 percent calcium carbonate equivalent; strongly alkaline (pH 8.6); gradual wavy boundary. (Combined thickness of Bk horizon is 12 to 50 inches)
C--44 to 60 inches; very pale brown (10YR 7/3) very fine sandy loam, yellowish brown (10YR 5/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine and fine roots; violently effervescent; calcium carbonate disseminated; strongly alkaline (pH 8.6). (0 to 40 inches thick).
TYPE LOCATION: Platte County, Wyoming; 5 miles east of Chugwater, about 2530 feet south and 350 feet east of the northwest corner of Section 24, T.21N., R.66W. 41 degrees 46 minutes 41 seconds north latitude and 104 degrees 43 minutes 44 seconds west longitude.
RANGE OF CHARACTERISTICS: Graystone soils typically effervesce throughout but some pedons may be leached in the A horizon where it is not cultivated. The depth to the calcic horizon ranges from 8 to 20 inches. The mollic epipedon is 7 to 10 inches thick. The soil is usually 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. It is dry for 60 consecutive days between July 1 and October 15 in most years. 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 value of 4 or 5 dry and chroma of 2 or 3. It is slightly alkaline or moderately alkaline. Texture is very fine sandy loam or fine sandy loam.
The Bk horizon has value of 5 through 8 dry and 4 through 6 moist, and chroma of 2 through 4. Texture is loam, very fine sandy loam, fine sandy loam or occasionally sandy loam with 6 to 18 percent clay. The range of fine and coarser sand is 15 to 35 percent. The calcic horizon averages 10 to 25 percent calcium carbonate equivalent. The reaction is slightly alkaline to strongly alkaline.
The C horizon, if present, has hue of 2.5YR or 10YR, value of 6 or 7 dry and 5 or 6 moist, and chroma of 2 through 4. Texture is very fine sandy loam or fine sandy loam. Calcium carbonate equivalent ranges from 5 to 20 percent. The reaction is slightly alkaline through strongly alkaline.
COMPETING SERIES: These are the Guy and Laird series. Guy soils have more than 15 percent rock fragments in the control section. Both Guy and Laird soils are intermittently moist in some or all parts of the moisture control section in July through September.
GEOGRAPHIC SETTING: Graystone soils are on hillslopes, terraces and fans. They formed in alluvium and eolian deposits derived from mixed sources. Slopes are 0 to 10 percent. Elevations are 4300 to 5800 feet. The average annual precipitation is 12 to 16 inches and the average annual air temperature is 46 to 48 degrees F. The frost-free season is 110 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alice, Bayard, Manter, Recluse and Treon soils. Alice soils have a cambic horizon, and are not calcareous to the surface. Bayard soils lack a calcic horizon. Manter and Recluse soils have an argillic horizon. Treon soils have bedrock at less than 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability.
USE AND VEGETATION: These soils are utilized for domestic livestock grazing, for wildlife habitat and for dryland cropland. The native vegetation is needleandthread, western wheatgrass, blue grama, threadleaf sedge, prairie junegrass, penstemon and prairie clovers. Wheat and oats are the primary crops under cultivation.
DISTRIBUTION AND EXTENT: Graystone soils occur in eastern Wyoming. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES PROPOSED: Platte County, Wyoming, 1987.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 9 inches (Ap)
Calcic horizon - 9 to 44 inches (Bk1, Bk2)
Aridic subgroup - Moisture control section usually dry in most years.
SIR- WY1013
LRR-G