LOCATION RAPIDCREEK SD+WY
Established Series
JWW/DJB
09/2011
RAPIDCREEK SERIES
The Rapidcreek series consists of very deep, well or somewhat excessively drained soils that formed in mixed alluvium derived from sedimentary and igneous sources. Rapidcreek soils are on flood plains and terraces. Slopes range from 1 to 10 percent. Mean annual precipitation is about 560 mm and the mean annual temperature is about 6 degrees C.
TAXONOMIC CLASS: Loamy-skeletal over sandy or sandy-skeletal, mixed, superactive, calcareous, frigid Typic Udifluvents
TYPICAL PEDON: Rapidcreek gravelly loam, on a southwest facing, linear slope of 2 percent in mixed forest-grassland vegetation at an elevation of about 1,345 meters. (Colors are for moist soil unless otherwise noted.) When described on July 9, 2004 the soil was moist throughout.
A--0 to 4 cm; very dark grayish brown (10YR 3/2) gravelly loam, dark grayish brown (10YR 4/2) dry; weak medium and moderate fine granular structure; soft, very friable, slightly sticky; many very fine, common fine and medium roots; about 15 percent subrounded limestone gravel and subangular channers; slight effervescence; slightly alkaline; abrupt smooth boundary. (2 to 15 cm thick)
C1--4 to 20 cm; about 80 percent stratified dark grayish brown (10YR 4/2) very gravelly loam, light brownish gray (10YR 6/2) dry, and 20 percent grayish brown (10YR 5/2) fine sandy loam, light brownish gray (10YR 6/2) dry; weak medium platy structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine, common fine and medium roots; about 40 percent subangular and subrounded gravel, 2 percent subrounded cobble; strong effervescence; moderately alkaline; clear wavy boundary.
C2--20 to 38 cm; about 80 percent brown (10YR 4/3), pale brown (10YR 6/3) dry, and 20 percent dark brown (10YR 3/3), brown (10YR 5/3) dry very gravelly fine sandy loam; massive; slightly hard, friable, slightly sticky and slightly plastic; many very fine, common fine and medium roots; about 43 percent subangular and subrounded gravel and 2 percent subrounded cobbles; strong effervescence; moderately alkaline; clear wavy boundary. (Combined thickness of the C horizon is 25 to 51 cm)
2C3--38 to 53 cm; dark grayish brown (10YR 4/2) very gravelly loamy coarse sand, light brownish gray (10YR 6/2) dry; massive; soft, very friable, nonsticky and nonplastic; common very fine and finea and few medium roots; about 50 percent subangular and subrounded gravel; violent effervescence; moderately alkaline; clear wavy boundary.
2C4--53 to 157 cm; brown (10YR 4/3) extremely cobbly loamy coarse sand, pale brown (10YR 6/3) dry; single grain; loose; common very fine and few fine and medium roots; about 70 percent mixed sedimentary fragments, of which 35 percent are rounded cobbles, 30 percent subrounded and rounded gravel,and 5 percent rounded stones; strong effervescence; moderately alkaline; clear wavy boundary.
3C5--157 to 173 cm; 60 percent dark grayish brown (10YR 4/2) gravelly fine sandy loam, grayish brown (10YR 5/2) dry, and 40 percent very dark grayish brown (10YR 3/2) gravelly very fine sandy loam, dark grayish brown (10YR 4/2) dry; massive; soft, very friable; few very fine and fine roots; 30 percent mixed sedimentary fragments, of which 20 percent are subrounded gravel and 10 percent rounded cobble; violent effervescence; moderately alkaline; clear wavy boundary. (0 to 20 cm thick)
2C4'--173 to 200 cm (68 to 80 inches); brown (10YR 4/3) extremely cobbly loamy coarse sand, pale brown (10YR 6/3) dry; single grain; loose; few very fine roots; 60 percent mixed sedimentary fragments, of which 40 percent are rounded cobble and 20 percent rounded gravel; strong effervescence; moderately alkaline. (Combined thickness of the 2C horizon is 102 to 171 cm)
TYPE LOCATION: Lawrence County, South Dakota; about 0.5 miles north of Maurice, between Highway 14A and Spearfish Creek; about 1,000 feet north and 1,700 feet west of the southeast corner of Sec. 8, T. 5 N., R. 2 E.; Maurice USGS topographic quadrangle, South Dakota; GPS 44 degrees 24 minutes 20.3 seconds north latitude and 103 degrees 53 minutes 53.2 seconds west longitude; NAD 83.
RANGE IN CHARACTERISTICS:
Depth to effervescence: 0 to 15 cm
Depth to contrasting particle-size class or lithologic discontinuity: 30 to 60 cm
A horizon:
Hue: 5YR to 10YR
Value: 3 or 4, 4 to 6 dry
Chroma: 2 to 4
Texture: GR-L, CB-L
Clay content: 18 to 27 percent
Rock fragments: 15 to 35 percent gravel and/or cobble
Reaction: neutral or slightly alkaline
C horizon:
Hue: 5YR to 10YR
Value: 3 to 6, 5 to 7 dry
Chroma: 2 to 6
Texture: stratified LS, SL, FSL, VFSL, L, SIL, CL (fine-earth fraction)
Clay content: 15 to 27 percent horizon average; individual strata may contain more or less
Rock fragments: 35 to 60 percent rounded and subrounded, mixed sedimentary and igneous fragments; 20 to 45 percent gravel and 2 to 40 percent cobble
Calcium carbonate equivalent: 2 to 15 percent
Reaction: slightly alkaline or moderately alkaline
2C horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5, 5 or 6 dry
Chroma: 2 to 4
Texture: stratified LS, S, LCOS, COS (fine-earth fraction)
Clay content: 3 to 10 percent horizon average
Rock fragments: 50 to 80 percent rounded and subrounded, mixed sedimentary and igneous fragments; 20 to 50 percent cobble, 10 to 40 percent gravel, and 0 to 10 percent stones
Calcium carbonate equivalent: 1 to 5 percent
Reaction: slightly alkaline to moderately alkaline
3C horizon (when present):
Hue: 10YR
Value: 3 or 4, 4 or 5 dry
Chroma: 2 or 3
Texture: L, FSL, VFSL (fine-earth fraction)
Clay content: 15 to 25 percent
Rock fragments: 15 to 35 percent rounded and subrounded gravel and/or cobble
Calcium carbonate equivalent: 2 to 10 percent
Reaction: moderately alkaline or strongly alkaline
COMPETING SERIES: There are no competing series in this taxonomic class.
GEOGRAPHIC SETTING:
Parent material: Alluvium derived primarily from mixed sedimentary sources, but also including minor components of igneous- and metamorphic-derived material
Landform: flood plains and low terraces in mountain valleys and canyon floors
Slopes: 1 to 10 percent
Elevation: 1,158 to 1,830 meters
Mean annual air temperature: 6 to 9 degrees C
Mean annual precipitation: 455 to 710 mm
Precipitation pattern: Over half of the average annual precipitation falls as rain and snow from March through July
Frost-free period: 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
Bullflat,
Cordeston, and
Marshbrook - have mollic epipedons and are fine-loamy. In addition, Bullflat soils have an argillic horizon, Cordeston soils have a cumulic mollic epipedon, and Marshbrook soils have a aquic moisture regime. Bullflat soils occur on higher landscape positions and Cordeston soils occur on slightly higher and Marshbrook soils on slightly lower landscape positions than Rapidcreek soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well to somewhat excessively drained; saturated hydraulic conductivity is high over very high; low to medium runoff; rarely to occasionally flooded for very brief to brief periods during the months of April through August.
USE AND VEGETATION: Rapidcreek soils have a riparian or mixed woodland and grassland ecological community and are utilized for livestock grazing, wildlife habitat, recreation, and limited homesite development. Common vegetation present on most areas includes Timothy, Kentucky bluegrass, smooth brome, sedges, cottonwood, boxelder, green ash, and occasional ponderosa pine and Black Hills spruce.
DISTRIBUTION AND EXTENT: Rapidcreek soils occur in valleys and canyons on the Limestone Plateau physiographic area in 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: Update Soil Survey of Lawrence County, South Dakota, 2006. The name is taken from Rapid Creek.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 25 to 100 cm (C2, C3, and 2C4 horizons)
Ochric epipedon: The zone from 0 to 4 cm (A horizon)
Strongly contrasting particle-size classes: At the lower boundary of the C2 horizon
Lithologic discontinuity: At the upper boundary of the 2C3 horizon and at the upper boundary of the 3C5 horizon.
Other features: Fluventic suborder, an irregular decrease in organic matter
The assignment of the cation-exchange activity class is derived from lab data from the typical pedon.
Taxonomic Version: Keys to Soil Taxonomy, Eleventh Edition, 2010
ADDITIONAL DATA:
National Cooperative Soil Survey
U.S.A.