LOCATION CLARKSVILLE MO+AL AR GA IL KS KY OK TN VAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, siliceous, semiactive, mesic Typic Paleudults
TYPICAL PEDON: Clarksville gravelly silt loam - in a hardwood forest. (Colors are for moist soil unless otherwise stated.)
0i--0 to 1 inch; partly decomposed organic matter; abrupt smooth boundary. (1/2 to 2 inches thick)
A--1 to 5 inches; dark grayish brown (10YR 4/2) gravelly silt loam; moderate fine granular structure; friable; common fine and few medium and coarse roots; many fine interstitial and tubular pores; 2 percent chert cobbles and 30 percent chert gravel; very strongly acid; clear smooth boundary. (1 to 4 inches thick)
E--5 to 12 inches; 60 percent light yellowish brown (10YR 6/4) and 40 percent brown (10YR 5/3) gravelly silt loam; weak fine subangular blocky structure; friable; few fine to coarse roots; few fine tubular pores; few distinct dark grayish brown (10YR 4/2) organic stains in root channels and/or pores and few prominent black (N 2/0) manganese or iron-manganese stains on rock fragments; 20 percent chert gravel; very strongly acid; clear smooth boundary. (6 to 27 inches thick)
Bt1--12 to 18 inches; light yellowish brown (10YR 6/4) gravelly silt loam; moderate fine subangular blocky structure; friable; few fine to coarse roots; common fine vesicular and tubular pores; few faint dark yellowish brown (10YR 4/4) clay films on faces of peds and few prominent black (N 2/0) manganese or iron-manganese stains on faces of peds; 20 percent chert gravel; strongly acid; clear smooth boundary. (0 to 9 inches thick)
Bt2--18 to 29 inches; yellowish brown (10YR 5/6) very gravelly loam; weak fine subangular blocky structure; firm; common fine and medium roots; common fine tubular pores; many distinct light brownish gray (10YR 6/2) silt coats on faces of peds and few distinct strong brown(7.5YR 4/6) clay films on faces of peds; 3 percent chert cobbles and 45 percent chert gravel; strongly acid; clear smooth boundary.
2Bt3--29 to 41 inches; yellowish brown (10YR 5/6) extremely gravelly clay loam; moderate fine subangular blocky structure; firm; few fine and medium roots; common fine tubular pores; common distint reddish brown (5YR 4/4) clay films on faces of peds and common prominent very pale brown (10YR 7/3) silt coats throughout; 15 percent chert cobbles and 55 percent chert gravel; strongly acid; clear wavy boundary.
2Bt4--41 to 52 inches; strong brown (7.5YR 5/6) very gravelly clay loam; moderate fine subangular blocky structure; firm; few fine to coarse roots; common fine tubular pores; common distinct red (2.5YR 4/6) clay films on faces of peds and few faint pale brown (10YR 6/3) silt coats on rock fragments; 10 percent chert cobbles and 40 percent chert gravel; strongly acid; gradual wavy boundary.
3Bt5--52 to 60 inches; red (2.5YR 4/6) cobbly clay; moderate fine angular blocky structure; very firm; few fine roots; few fine vesicular and few fine interstitial and tubular pores; common distinct strong brown (7.5YR 4/6) clay films on rock fragments and common prominent red (2.5YR 4/8) clay films on faces of peds and common distinct light brown (7.5YR 6/4) silt coats on faces of peds; 10 percent chert cobbles and 10 percent chert gravel; strongly acid. (Combined thickness of the Bt, 2Bt, and 3Bt horizons is 24 to 88 inches.)
TYPE LOCATION: Shannon County, Missouri; 75 feet east and 640 feet south of the northeast corner, sec. 33, T. 29 N., R. 1 W.; USGS Exchange, Missouri quadrangle; Latitude 37 degrees 8 minutes 32.4 seconds north and Longitude 91 degrees 4 minutes 12.8 seconds west, NAD 83; UTM coordinates 4,112,195 meters N. and 671,410 meters E., Zone 15, NAD27.
RANGE IN CHARACTERISTICS:
Depth to Bedrock: greater than 80 inches
Depth to argillic horizon: 7 to 40 inches
Depth to horizons with more than 40 percent clay: 36 to 54 inches
Note: The particle size control section averages 18 to 35 percent clay, 5 to 40 percent sand, and 35 to 70 percent rock fragments. Reaction ranges from moderately acid to extremely acid.
A horizon
Hue: 10YR
Value: 2 to 6
Chroma: 1 to 4
Fine-earth: silt loam or silt
Rock fragments: 10 to 80 percent gravel, 0 to 30 percent cobbles
Ap horizon
Hue: 10YR
Value: 4 to 6
Chroma: 2 to 4
Fine-earth: silt loam or silt
Rock fragments: 1 to 80 percent gravel
E horizon
Hue: 10YR
Value: 4 to 7
Chroma: 2 to 6
Fine-earth: silt loam, silt, or loam
Rock fragments: 20 to 80 percent
BE (where present) and Bt horizons
Hue: 2.5YR to 10YR
Value: 4 to 6
Chroma: 4 to 6
Fine-earth: silty clay loam, loam, or silt loam
Rock fragments: 20 to 80 percent
2Bt and 2C horizons
Hue: 2.5YR to 10YR
Value: 3 to 6
Chroma: 4 to 6
Fine-earth: loam, silt loam, clay loam, silty clay loam, silty clay, or clay
Rock fragments: 30 to 80 percent
3Bt horizon
Hue: 2.5YR to 10YR
Value: 3 to 6
Chroma: 4 to 6
Fine-earth: clay
Rock fragments 7 to 60 percent
COMPETING SERIES: These are the Bouldin and Coulstone series. Bouldin soils have 20 to 55 percent sand coarser than fine sand in the B horizons, contain sandstone fragments and no chert fragments, and loam, sandy loam, and clay loam textures. Coulstone soils contain more than 40 percent sand in the Bt horizon.
GEOGRAPHIC SETTING: Clarksville soils are on steep side slopes and narrow ridgetops. Slopes range from 1 to 70 percent. The soils formed in hillslope sediments and the underlying clayey residuum from cherty dolomite or cherty limestone. The mean annual temperature ranges from 54 to 57 degrees F, and the mean annual precipitation ranges from 40 to 46 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the competing Coulstone soils, these are the Captina, Hobson, Lebanon, Nixa, Noark, Poyner, and Wilderness soils. Captina, Hobson, Lebanon, Nixa, and Wilderness soils have fragipans and are on higher broad, nearly level to gently sloping ridgetops. Noark soils are clayey-skeletal and Poyner soils are loamy- skeletal over clayey. These soils are on similar landscape positions.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained. Runoff is medium to very high. Permeability is moderate. The saturated hydraulic conductivity is moderately high.
USE AND VEGETATION: Most areas are in second growth timber. Some areas are used for pasture or hayland, and small areas are cropped to corn, small grains, and sorghum. Native vegetation is mixed forest of black oak, white oak, blackjack oak, post oak, shortleaf pine, hickory, ash, sugar maple, and dogwood.
DISTRIBUTION AND EXTENT: Ozark region (MLRAs 116A and 116B) of Kansas, Missouri, Oklahoma, and Arkansas, and dissected cherty areas in other states of the southeastern United States. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Montgomery County, Tennessee, 1901.
REMARKS:The type location was moved to Shannon County, Missouri in 2002 because the original site is no longer accessable.
Diagnostic horizons and features recognized in this series are:
1) Ochric epipedon - the zone from the mineral surface of the soil to a depth of 12 inches (A and E horizons)
2) Argillic horizon - the zone from approximately 12 to 60 plus inches (Bt1, Bt2, 2Bt3, 2Bt4, and 3Bt5 horizons)
ADDITIONAL DATA: The Missouri Soil Characterization Laboratory reference number for this pedon is M9561364.