LOCATION CRYDESTON SD+WY
Established Series
JWW,DJB
09/2011
CRYDESTON SERIES
The Crydeston series consists of very deep, well drained soils that formed in alluvium derived primarily from sedimentary sources. Crydeston soils are in mountain valleys. Slopes range from 0 to 10 percent. Mean annual precipitation is about 710 millimeters and the mean annual temperature is about 7.0 degrees C.
TAXONOMIC CLASS: Fine-silty, mixed, superactive Pachic Palecryolls
TYPICAL PEDON: Crydeston silt loam, on a northwest facing, slightly concave slope of 1 percent in grassland at an elevation of 1,913 meters. (Colors are for moist soil unless otherwise noted.) When described on July 9, 2004 the soil was moist.
A1--0 to 9 cm; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; strong very fine and fine and moderate medium granular structure; soft, friable, nonsticky and slightly plastic; many very fine and few fine roots throughout; strongly acid; clear wavy boundary.
A2--9 to 34 cm; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; weak fine and medium subangular blocky structure parting to moderate fine granular; slightly hard, friable, nonsticky and slightly plastic; many very fine and few fine roots throughout; few very fine and fine continuous tubular pores; common medium faint black (10YR 2/1) moist irregularly shaped worm casts throughout; moderately acid; clear smooth boundary. (Combined thickness of the A horizon is 23 to 41 cm)
AB--34 to 56 cm; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; weak medium subangular blocky structure parting to moderate fine subangular blocky; slightly hard, very friable, nonsticky and slightly plastic; many very fine and few fine roots throughout; many very fine and few fine continuous tubular pores; few medium faint black (10YR 2/1) moist irregularly shaped worm casts throughout; slightly acid; clear wavy boundary. (0 to 25 cm thick)
Bw1--56 to 94 cm; very dark grayish brown (10YR 3/2) silt loam, dark grayish brown (10YR 4/2) dry; weak medium prismatic structure parting to moderate medium and coarse angular blocky; slightly hard, very friable, nonsticky and slightly plastic; common very fine and few fine roots throughout; many very fine and few fine continuous tubular pores; slightly acid; clear wavy boundary.
Bw2--94 to 108 cm; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine and medium subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; common very fine and few fine roots throughout; common very fine and few fine continuous tubular pores; slightly acid; clear wavy boundary. (Combined thickness of the Bw horizon is 30 to 71 cm)
2A/Btb--108 to 125 cm; about 80 percent very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry, and 20 percent brown (7.5YR 4/4) silty clay loam, brown (7.5YR 5/4) dry; weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots throughout; common very fine and few fine discontinuous tubular pores; about 20 percent prominent very dark gray (10YR 3/1) organoargillans on surfaces along pores and root channels (Btb part); about 10 percent fine and medium subrounded limestone gravel; slightly alkaline; clear irregular boundary. (0 to 17 cm thick)
2Btb--125 to 192 centimeters; about 60 percent dark brown (7.5YR 3/4) very gravelly clay loam, brown (7.5YR 4/4) dry, and 40 percent very dark gray (10YR 3/1) very gravelly silt loam, gray (10YR 5/1) dry; weak medium subangular blocky structure; very hard, firm, slightly sticky and moderately plastic; few fine and very fine roots throughout; few very fine discontinuous pores; about 20 percent faint brown (7.5YR 4/3) clay films on surfaces along pores and root channels; about 55 percent limestone rock fragments, including 40 percent subangular, subrounded, and rounded gravel and 15 percent subrounded cobbles; disseminated calcium carbonate throughout; very slightly effervescent; moderately alkaline; gradual irregular boundary. (46 to 71 cm thick)
3Cr--192 to 203 centimeters; very pale brown (10YR 7/3), light gray (10YR 7/2) and white (10YR 8/1) very slightly effervescent; weakly cemented limestone.
TYPE LOCATION: Lawrence County, South Dakota; about 20 miles southwest of Spearfish, South Dakota; about 1540 feet north and 2500 feet east of the southwest corner of Sec. 33, T. 4 N., R. 1 E.; Old Baldy Mountain USGS quad; 44 degrees 15 minutes 40.6 seconds N. latitude and 104 degrees 00 minutes 21.9 seconds W. longitude; NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon: greater than 76 cm
Particle-size control section (weighted average):
Clay content: 20 to 30 percent
Sand content: 5 to 15 percent
A horizon:
Hue: 10YR
Value: 2, 3 or 4 dry
Chroma: 1 or 2
Texture: SIL
Clay content: 18 to 27 percent
Rock fragments: 0 to 5 percent
Reaction: slightly acid to strongly acid
The AB horizon, when present, has physical and chemical properties similar to the respective A and Bw horizons.
Bw horizon:
Hue: 10YR
Value: 2 to 4, 4 to 6 dry
Chroma: 1 or 2
Texture: SIL, SICL
Clay content: 18 to 30 percent
Rock fragments: 0 to 5 percent
Pararock fragments: 0 to 5 percent
Reaction: slightly or moderately acid
The 2A/Btb horizon, when present, consists of a buried A horizon combined with a Bt horizon. Each component has properties similar to their respective parts.
2Btb horizon:
Hue: 7.5YR or 10YR
Value: 3 or 4, 4 or 5 dry
Chroma: 1 to 4
Texture: (ine-earth fraction): loam, silt loam or clay loam
Clay content: 20to 34percent
Rock fragments: 35 to 60 percent; fragments consist of 30 to 45 percent subangular, subrounded, and/or rounded limestone gravel and 5 to 15 percent subangular and subrounded limestone cobble
Pararock fragments: 5 to 10 percent very weakly or weakly cemented limestone gravel
Reaction: neutral to mildly alkaline
Cr horizon (when present):
Hue: 10YR
Value: 7 to 8
Chroma: 1 to 4
Texture: Unweathered limestone bedrock (weakly to moderately cemented)
COMPETING SERIES:
Robin - formed dominantly in loess deposits and have xeric moisture regime.
GEOGRAPHIC SETTING:
Parent material: Alluvium derived from sedimentary sources (primarily limestone and fine-grained sandstone)
Landform: footslopes in mountain valleys
Slopes: 0 to 10 percent
Elevation: 1,830 to 2,160 meters
Mean annual air temperature: 4 to 7 degrees C
Mean annual precipitation: 660 to 820 millimeters
Precipitation pattern: In most years, about half the annual precipitation occurs as snow or rain during the period March through mid-July.
Frost-free period: 60 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
Gillum (T) and
Jenksdraw (T) -have a mollic epipedon less than 41 centimeters thick; these soils occur on higher slopes than Crydeston soils
Marshbrook - are poorly and very poorly drained; they occur on toeslopes in lower drainageways
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately high to saturated hydraulic conductivity.
USE AND VEGETATION: Crydeston soils are in grassland and utilized for livestock grazing and wildlife habitat. Most areas are dominated by timothy, smooth bromegrass, and minor remnant native species. The native vegetation includes
several species of wheatgrass, needlegrass, and bluegrass.
DISTRIBUTION AND EXTENT: Crydeston soils occur in the High Limestone Plateau physiographic area of the Black Hills of South Dakota and Wyoming; LRR G, MLRA 62; the series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES PROPOSED: Extension revision of the Soil Survey of Lawrence County, South Dakota. 2007. The name is a derivative of the similar Cordeston soil, found at lower elevations in the Black Hills.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Soil moisture: Typic-udic.
Particle-size control section: The zone from 25 to 100 cm (AB, Bw1, and Bw2 horizons)
Mollic epipedon: The zone from 0 to 125 cm (A1, A2, AB, Bw1, Bw2, 2A/Btb horizons)
Argillic horizon: The zone from 125 to 192 cm (Btb horizon)
Paralithic contact: The contact with weakly cemented limestone at 192 cm (Cr horizon)
Lithologic discontinuity: At the upper boundary of the 2A/Btb horizon.
Other features: A buried A horizon typically occurs between depths of 96 and 114 cm
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Keys to Soil Taxonomy, Eleventh Ed., 2010
ADDITIONAL DATA:
National Cooperative Soil Survey
U.S.A.