LOCATION ROCHEPORT MOEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Oxyaquic Hapludalfs
TYPICAL PEDON: Rocheport silt loam - on a 17 percent slope with a northeastern aspect in a mixed forest of deciduous hardwoods and cedars. (Colors are for moist soil unless otherwise stated.)
Oi--0.5 to 0 inches; 100% undecomposed leaf litter cover.
A--0 to 1 inch; finely mixed black (10YR 2/1) and dark brown (10YR 3/3) silt loam; moderate very fine granular and moderate very fine subangular blocky structure; very friable; many very fine and fine and few medium roots; slightly acid; abrupt wavy boundary. (1 to 5 inches thick)
E--1 to 5 inches; brown (10YR 5/3) silt loam; common faint yellowish brown (10YR 5/6) mottles of B horizon material and few faint dark brown (10YR 3/3) mottles of A horizon material; moderate thin platy structure parting to weak very fine subangular blocky; very friable; many very fine, fine, and medium and common coarse roots; moderately acid; clear smooth boundary. (0 to 10 inches thick)
Bt1--5 to 12 inches; yellowish brown (10YR 5/6) silty clay loam; moderate fine and very fine subangular blocky structure; friable; few very fine, common fine, many medium and coarse roots; many faint yellowish brown (10YR 5/4) clay films on faces of peds; very strongly acid; diffuse wavy boundary.
Bt2--12 to 18 inches; yellowish brown (10YR 5/6) silty clay loam; moderate fine subangular blocky structure; firm; few very fine, common fine, few medium and coarse roots; common distinct yellowish brown (10YR 5/4) and few distinct brown (10YR 5/3) clay films on faces of peds; few fine distinct brown (10YR 5/3) iron depletions in the matrix, increasing with depth; many fine iron and manganese stains; few fine iron and manganese concretions; very strongly acid; gradual smooth boundary.
Bt3--18 to 30 inches; yellowish brown (10YR 5/6) silty clay loam; weak fine subangular blocky structure; firm; few very fine, fine, and medium roots; many faint clay films on faces of peds; many fine light brownish gray (10YR 6/2) and pale brown (10YR 6/3) iron depletions in matrix and along root and pore channels; few coarse gray (10YR 5/1) iron depletions along pores containing dead roots; many fine iron and manganese stains; common fine iron and manganese concretions; strongly acid; gradual wavy boundary. (The combined thickness of the Bt horizon is 15 to 40 inches.)
2Bt4--30 to 39 inches; pale brown (10YR 6/3) silty clay; moderate fine prismatic structure parting to moderate fine and very fine subangular blocky; firm; few very fine and fine roots; many faint and distinct clay films on faces of peds; many faint pressure faces, some angled; many fine prominent yellowish brown (10YR 5/6) iron accumulations and common fine faint light brownish gray (10YR 6/2) iron depletions in the matrix; common fine iron and manganese stains; common fine and medium iron and manganese concretions; neutral; clear wavy boundary.
2Bt5--39 to 48 inches; yellowish brown (10YR 5/8) and brownish yellow (10YR 6/8) clay; weak fine prismatic structure parting to moderate fine subangular blocky; firm; few very fine and fine roots; common faint clay films on faces of peds; few distinct and prominent yellowish brown (10YR 5/6) clay films on faces of peds; many medium and coarse prominent pale brown (10YR 6/3) and many coarse faint light brownish gray (10YR 6/2) iron depletions in the matrix; few fine iron and manganese stains; few chert pebbles; neutral; abrupt smooth boundary. (The combined thickness of the 2Bt horizon is 5 to 20 inches.)
2Cr--48 to 52 inches; light gray (2.5Y 7/2) saprolite that crushes to silt loam, with residual gravel; few very fine roots in occasional fractures; very firm; many coarse prominent brownish yellow (10YR 6/6) iron accumulations in the matrix; iron and manganese stains on joints; slightly effervescent; moderately alkaline; abrupt smooth boundary. (0 to 5 inches thick)
2R--52 inches; smooth, white "cotton rock" dolostone
TYPE LOCATION: Boone County, Missouri, about 2 miles east-southeast of Hartsburg, 2300 feet due west of the southeast corner of section 10, T. 45 N., R. 12 W; Hartsburg quadrangle; lat. 38 degrees 41 minutes 14 seconds N. and long. 92 degrees 15 minutes 48 seconds W.
RANGE IN CHARACTERISTICS: Depth to a paralithic or lithic contact is 40 to 60 inches. Depth to horizons with more than 35 percent clay (2Bt) ranges from 30 to 45 inches. Average clay content in the particle-size control section ranges from 30 to 35 percent.
The A horizon has value of 2 to 4 and chroma of 1 to 3. Reaction is strongly acid to neutral.
The E horizon has value of 5 or 6 and chroma of 3 or 4. Reaction is very strongly to moderately acid.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 to 6 and chroma of 3 to 6. Redoximorphic features are in lower subhorizons. Texture is silt loam or silty clay loam. Reaction is very strongly to moderately acid.
The 2Bt horizon hue is typically 7.5YR or 10YR, but ranges to 5YR. Value is 4 to 6 and chroma is 3 to 8. Texture commonly is silty clay or clay and less commonly silty clay loam. Rock fragment content ranges from 0 to 15 percent. Reaction is strongly acid to neutral.
COMPETING SERIES: These are the Birkbeck, Cadiz, Campton, Elco, Eleroy, Hedrick, Homen, Inton, Iona, Libre, Mayville, Minnith, Morningsun (T), Newvienna, Redbud, Rockfield, Somonauk, Uniontown, Winfield, and Zurich soils. Birkbeck, Cadiz, Campton, Elco, Hedrick, Homen, Inton, Iona, Libre, Mayville, Minnith, Morningsun (T), Newvienna, Redbud, Rockfield, Somonauk, Uniontown, Winfield, and Zurich soils do not have a paralithic or lithic contact above a depth of 60 inches. Eleroy soils have a paralithic contact with calcareous, clayey shale at a depth of 40 to 60 inches.
GEOGRAPHIC SETTING: Rocheport soils are on moderately steep to steep side slopes, generally the upper parts, of hills in uplands. They have formed in loess, thought to be Holocene, and residuum from limestone or dolostone that is low in chert content. The underlying bedrock is thought to be primarily Ordovician or Mississippian in age. Slopes range from 14 to 40 percent. Mean annual temperature ranges from 54 to 57 degrees F., and mean annual precipitation ranges from 32 to 40 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the well drained Bonnefemme, Clinkenbeard, Menfro series and the moderately well drained Winfield series. Bonnefemme and Clinkenbeard soils are generally down slope from the Rocheport soils, are 20 to 40 inches deep to bedrock, and have a finer texture argillic horizon. Menfro and Winfield soils are generally up slope and are more than 60 inches to bedrock.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is moderately slow. Surface runoff potential is high. In undisturbed areas the upper depth of a perched water table is at 2.5 to 4 feet during November to April in most years.
USE AND VEGETATION: Most areas are in deciduous hardwood forests, and are used for timber production and wildlife habitat. A few areas are in pasture.
DISTRIBUTION AND EXTENT: Central Missouri uplands. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Boone County, Missouri, 1998. Source of the name is a small town in western Boone County.
REMARKS: Diagnostic horizons and features recognized in this series are: ochric epipedon - the zone from the surface of the soil to a depth of 5 inches (A and E horizons); argillic horizon - the zone from approximately 5 to 48 inches (Bt1, Bt2, Bt3, 2Bt4, and 2Bt5 horizons).
ADDITIONAL DATA: Four pedons have been described and sampled for lab analysis at the University of Missouri Soil Characterization Lab. The sample number of this pedon is M9201955.