LOCATION CITADEL SD+WYEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Typic Hapludalfs
TYPICAL PEDON: Citadel silt loam, on a northeast facing, linear slope of 4 percent, under ponderosa pine forest at an elevation of about 1470 meters. When described on July 15, 1999 the soil was slightly moist to moist throughout. (Colors are for moist soil unless otherwise stated.)
0i--0 to 4 cm; slightly decomposed pine forest litter; abrupt smooth boundary. (0.5 to 7 cm thick)
A--4 to 7 cm; black (10YR 2/1) silt loam, very dark gray (10YR 3/1) dry; moderate very fine and fine granular structure; slightly hard, very friable, nonsticky and nonplastic; common very fine, few fine and medium roots; common fine irregular pores; strongly acid; abrupt smooth boundary. (0 to 16 cm thick)
E--7 to 21 cm; brown (10YR 5/3) silt loam, pale brown (10YR 6/3) dry; moderate medium and fine platy structure parting to weak medium and coarse subangular blocky; moderately hard, very friable, nonsticky and nonplastic; common very fine, few fine, medium and coarse, roots; few very fine tubular pores throughout; common (3 percent) black (10YR 2/1) medium worm casts throughout; moderately acid; abrupt wavy boundary. (8 to 30 cm thick)
Bt/E--21 to 35 cm; about 65 percent brown (7.5YR 4/3) silty clay loam, brown (7.5YR 5/3) dry (Bt part), and 35 percent brown (10YR 5/3) silt loam, pale brown (10YR 6/3) dry (E part); strong fine and medium angular blocky structure; moderately hard, firm, slightly sticky and moderately plastic; common very fine, few fine, medium and coarse roots; few fine and very fine tubular pores throughout; many (75 percent) faint brown (7.5YR 4/3) continuous clay films on vertical faces of peds, and common (10 percent) distinct very dark gray (7.5YR 3/1) organoargillans on vertical faces of peds; slightly acid; clear wavy boundary. (0 to 15 cm thick)
Bt1--35 to 57 cm; brown (7.5YR 4/3) silty clay, brown (7.5YR 5/3) dry; strong medium prismatic structure parting to strong fine and medium angular blocky; hard, very firm, moderately sticky and very plastic; few very fine, fine, medium, and coarse roots; common very fine tubular pores throughout; many (75 percent) faint brown (7.5YR 4/3) continuous clay films on vertical faces of peds, and common (10 percent) distinct very dark gray (7.5YR 3/1) organoargillans on vertical faces of peds; slightly acid; gradual wavy boundary.
Bt2--57 to 76 cm; brown (10YR 4/3) silty clay loam, brown (10YR 5/3) dry; moderate medium prismatic structure parting to strong medium subangular blocky; hard, firm, moderately sticky and moderately plastic; few very fine, fine, medium and coarse roots; common very fine tubular pores throughout; 3 percent subrounded limestone and calcareous sandstone gravel; common (20 percent) distinct brown (7.5YR 4/3) continuous clay films on vertical faces of peds, and common (10 percent) prominent very dark gray (7.5YR 3/1) organoargillans on vertical faces of peds; neutral; clear wavy boundary. (Combined thickness of the Bt horizon is 25 to 90 cm)
Btk1--76 to 88 cm (30 to 34.5 inches); olive brown (2.5Y 4/3) clay loam, brown (10YR 5/3) dry; moderate medium and coarse subangular blocky structure; very hard, firm, slightly sticky and moderately plastic; 3 percent subrounded limestone and calcareous sandstone gravel, 1 percent cobble; common (30 percent) distinct brown (7.5YR 4/3) continuous clay films on vertical faces of peds, and few (5 percent) prominent very dark gray (7.5YR 3/1) organoargillans on vertical faces of peds; common very fine tubular pores throughout; few coarse, medium, fine, and very fine roots; matrix is noneffervescent, but has common fine distinct white (10YR 8/1), very weakly cemented spherical masses and threads of calcium carbonate; slightly alkaline; clear wavy boundary.
Btk2--88 to 128 cm; light olive brown (2.5Y 5/3) silt loam, pale brown (10YR 6/3) dry; weak medium prismatic parting to moderate medium and coarse subangular blocky; very hard, firm, slightly sticky and moderately plastic; few coarse, medium, fine, and very fine roots; common very fine tubular pores throughout; 1 percent subrounded limestone gravel and 1 percent cobble; common (30 percent) distinct yellowish brown (10YR 5/4) continuous clay films on vertical faces of peds; many medium and coarse distinct very pale brown (10YR 8/2) very weakly cemented irregular threads of calcium carbonate in matrix, lining pores, and around rock fragments; violent effervescence; moderately alkaline; gradual wavy boundary. (Combined thickness of the Btk horizon is 0 to 50 cm)
Bk--128 to 203 cm; light olive brown (2.5Y 5/4) silt loam, light yellowish brown (10YR 6/4) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few fine and very fine roots; common very fine dendritic-tubular pores throughout; 6 percent rock fragments, of which 2 percent are subrounded limestone gravel, 3 percent cobble, and 1 percent stones; few (10 percent) distinct yellowish brown (10YR 5/4) continuous clay films on vertical faces of peds; many medium and coarse distinct very pale brown (10YR 8/2), very weakly cemented irregular threads of calcium carbonate in matrix, lining pores, and around rock fragments; strong effervescence; moderately alkaline. (20 to 75 cm thick)
TYPE LOCATION: Lawrence County, South Dakota; about 3.3 km (2 miles) northeast of Nemo, at the upper end of South Stagebarn Canyon; 280.4 meters (920 feet) south and 442 meters (1,450 feet) west of the northeast corner of Sec. 23, T. 3 N., R. 5 E.; Piedmont quadrangle; 44 degrees, 12 minutes, 33 seconds north latitude and 103 degrees, 28 minutes, 43 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Typic-udic soil moisture regime.
Mean annual soil temperature: 4 to 8 degrees C
Mean summer soil temperature: 10 to 14 degrees C
Particle-size control section (weighted average):
Clay content: 35 to 45 percent
Sand content: 5 to 15 percent fine and coarser sand
A horizon:
Hue: 5YR, 7.5YR, or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 or 2
Texture: L, SIL, FSL, VFSL
Clay content: 10 to 25 percent
Reaction: strongly acid to neutral
E horizon:
Hue: 5YR, 7.5YR, or 10YR
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 2 or 3
Texture: L, SIL, FSL, VFSL
Clay content: 10 to 20 percent
Reaction: strongly acid to neutral
The Bt/E horizon has the combined properties of the Bt and E horizons.
Bt horizon:
Hue: 5YR, 7.5YR, 10YR, or 2.5Y
Value: 4 to 6 dry, 4 or 5 moist
Chroma: 3 to 6
Texture: CL, C, SICL, SIC
Clay content: 35 to 45 percent
Rock fragments: 0 to 20 percent limestone and/or calcareous sandstone gravel
Reaction: strongly acid to neutral (pH 5.1 to 7.3)
Btk horizon:
Hue: 5YR, 7.5YR, 10YR, or 2.5Y
Value: 4 to 6 dry, 4 or 5 moist
Chroma: 3 to 6
Texture: SIL, CL, SICL
Clay content: 25 to 40 percent
Rock fragments: 0 to 20 percent limestone and/or calcareous sandstone gravel
Reaction: slightly alkaline or moderately alkaline (pH 7.4 to 8.4)
Bk horizon:
Hue: 5YR, 7.5YR, 10YR, or 2.5Y
Value: 4 to 7 dry, 4 or 5 moist
Chroma: 3 to 6
Texture: L, CL, SIL, or SICL
Clay content: 20 to 35 percent
Rock fragments: 0 to 35 percent angular and subangular limestone and/or calcareous sandstone fragments. Reaction: slightly alkaline or moderately alkaline
A C horizon is present in some pedons. Where present, the C horizon can have 5 to 60 percent angular and subangular limestone and/or calcareous sandstone fragments.
COMPETING SERIES: There are no other series in this taxonomic family.
GEOGRAPHIC SETTING:
Parent material: residuum, local alluvium, or colluvium derived from limestone, calcareous sandstone, or soft shale
Landform: ridges, ridge shoulders, and hillslopes of mountains
Slopes: 2 to 50 percent
Elevation: 1,158 to 1,890 meters
Mean annual temperature: 4 to 7 degrees C
Mean annual precipitation: 508 to 762 mm
Precipitation pattern: over one-half the mean annual precipitation falls as snow and rain during the period March through July
Frost-free season: 60 to 110 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Paunsaugunt - are shallow to a lithic contact; generally they occur or rises and ridges above the Citadel
Tollflat (T) - have greater than 15 percent fine and coarser sand in the particle-size control section; they occur on similar landscape positions as Citadel
Vanocker - are loamy-skeletal; generally the occur on rises and ridges above Citadel
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to very high runoff, depending on slope; moderately low or moderately high saturated hydraulic conductivity
USE AND VEGETATION: Used for timber production, recreation and wildlife, homesite and urban development, and for grazing. Native vegetation is dominantly ponderosa pine with lesser amounts of Black Hills spruce, aspen, birch, and bur oak. Understory species include prairie dropseed, needlegrass, western wheatgrass, roughleaf ricegrass, and little bluestem. Shrubs include bearberry, oregon-grape, common juniper, hophorn bean, and snowberry.
DISTRIBUTION AND EXTENT: Low Limestone Plateau physiographic area of the Black Hills in western South Dakota and northeastern Wyoming; LRR G, MLRA 62. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Meade County, Southern Part, South Dakota, 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 4 to 21 cm; (A and E horizons)
Argillic horizon - 21 to 128 cm; (Bt/E, Bt1, Bt2, Btk1, and Btk2 horizons)
The typical pedon for the series is changed to one which was sampled for complete characterization and meets the current classification. The classification of the series is changed from Glossic Hapludalfs to Typic Hapludalfs because the color requirements for an albic horizon were not previously met.
Taxonomic Version: Keys to Soil Taxonomy, Tenth Ed., 2006
ADDITIONAL DATA: