LOCATION WOODROCK WY+CO MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Glossocryalfs
TYPICAL PEDON: Woodrock gravelly coarse sandy loam - forest (Colors are for dry 90il unless otherwise noted.)
0i--0 to 2 inches; Undecomposed organic material chiefly needles, bark, twigs, and leaves.
0e--2 to 3 inches; Partly decomposed organic material like the horizon above. Very strongly acid.
A--3 to 5 inches; brown (10YR 5/3) gravelly coarse sandy loam, dark brown (10YR 3/3) moist; strong fine crumb structure; soft, very friable; 15 percent fine angular gravel; strongly acid (pH 5.2); abrupt smooth boundary. (0 to 4 inches thick)
E--5 to 11 inches; light gray (10YR 7/2) gravelly coarse sandy loam, grayish brown (10YR 5/2) moist; moderate fine platy structure that parts to fine granules; soft, very friable, nonplastic; 20 percent fine angular gravel; strongly acid (pH 5.2); clear
wavy boundary. (3 to 10 inches thick)
E/B--11 to 16 inches; mixed colors including light gray (10YR 7/2) and brown (10YR 5/3) gravelly coarse sandy loam; grayish brown (10YR 5/2) and brown (10YR 4/3) moist; moderate fine subangular blocky structure; very hard, very friable, nonplastic, slightly sticky; 20 percent fine angular gravel; thin glossy patches on the faces of the more clayey peds; this horizon consists of seams and nodules of material like that of the underlying horizon embedded in a matrix like that of the overlying horizon; strongly acid (pH 5.3); gradual wavy boundary. (4 to 10 inches thick)
Bt--16 to 29 inches; brown (10YR 5/3) gravelly coarse sandy clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; extremely hard, friable, slightly plastic, slightly sticky; 25 percent fine angular gravel; thin wax-like coatings on faces of peds, in root channels and pores, and on faces of pebbles; strongly acid (pH 5.4); gradual smooth boundary. (9 to 34 inches thick)
BC--29 to 33inches; light yellowish brown (10YR 6/4) gravelly coarse sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; extremely hard, friable, nonplastic, slightly sticky; thin wax-like patches on faces of peds, and in some root channels; glossy coatings on some faces of pebbles; 25 percent fine angular gravel; strongly acid (pH 5.4); clear wavy boundary. (0 to 6 inches thick)
R--33 inches; unweathered granite bedrock.
TYPE LOCATION: Sheridan County, Wyoming; approximately 1,250 feet west of the SE corner sec. 24, T.54N., R.85W.
RANGE IN CHARACTERISTICS: In undisturbed areas, these soils usually have 0i, 0e, and A horizons but these horizons are very thin or absent or may have been destroyed or mixed in some pedons. In severely truncated areas the E, E/B, and a portion of the Bt horizon has been destroyed but enough of the Bt horizon remains to be clearly identifiable. Thickness of the solum in undisturbed areas ranges from 15 to 40 inches and depth to bedrock ranges from 20 to 40 inches. The top of the argillic horizon occurs above 24 inches and textures are finer than loamy fine sand in some subhorizon above this depth. These soils are moderately to very strongly acid and base saturation is less than 60 percent in at least a part of the solum. Organic carbon is at a maximum in the surface horizons and decreases uniformly with depth. The argillic horizon averages 18 to 35 percent clay. Content of fine or coarser sand exceeds 35 percent and a significant proportion of the sand fraction is medium and coarse angular sand. Packing patterns of sand grains within the matrix tend to be cubical with bearing surfaces between sand grains relatively flat. Horizons of low organic matter content have a greater than normal differential in consistence between moist and dry conditions. Content of coarse fragments usually exceeds 15 percent and ranges up to 35 percent and these are mostly fine and very fine angular gravel. Mean annual soil temperature ranges from 32 degrees to 46 degrees F. and mean summer soil temperature ranges from 40 degrees to 58 degrees F. if 0 horizons are thin and timber cover open, or 36 degrees to 46 degrees F. if 0 horizons are thick and timber stands are dense.
The E horizon has hue of 2.5Y through 7.5YR, value of 5 through 8 dry and 4 through 7 moist, and chroma of 1 through 4. It is very strongly acid to moderately acid (pH 4.5 to 6.0). This horizon usually has platy primary structure but it has granular or crumb structure in some pedons. It is soft to slightly hard.
The Bt horizon has hue of 2.5Y through 5YR, value of 5 through 7 dry and 4 through 6 moist, and chroma of 2 through 6. When hue is redder than 7.5YR, the coloration is inconsistent and limited to horizons of maximum weathering. This horizon is typically sandy clay loam but clay ranges from 18 to 35 percent, silt from 15 to 35 percent and sand from 40 to 75 percent with more than 35 percent fine or coarser sand and with significant amounts of medium and coarse sand. It is strongly acid to moderately acid pH 4.5 to 6.0). The Bt horizon usually has subangular blocky primary structure but has angular blocky structure in some pedons. It has oriented clay films in some parts, and weak skeletons are present on faces of peds in the upper part of the horizon in some pedons.
COMPETING SERIES: These are the Perceton, Schofield, and Shule series. Perceton soils are more than 40 inches deep.Schofield and Shule soils are slightly acid to neutral with more than 60 percent base saturation in all parts of the solum.
GEOGRAPHIC SETTING: Woodrock soils are on moderately to steeply sloping hills, ridges, and mountainsides. Slopes typically range from 3 percent to about 60 percent. The soil formed in moderately thin, noncalcareous, coarse sandy materials weathered residually from granite bedrock or on locally transported materials. At the type location the average annual precipitation is 24 inches with peak periods of precipitation in the spring and early summer months. Mean annual temperature is 32 degrees F., mean summer temperature is 48 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Burgess soils and the competing Schofield soils. Burgess soils have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well-drained; slow or medium runoff; moderate to rapid permeability.
USE AND VEGETATION: Native pastureland, recreation, and forestry. Native vegetation is spruce, fir, and a thin understory of shrubs.
DISTRIBUTION AND EXTENT: Mountainous areas of Colorado, Montana, and Wyoming. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Sheridan County, Wyoming, 1932.