LOCATION BONNEFEMME MOEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Hapludalfs
TYPICAL PEDON: Bonnefemme silt loam - on a 22 percent slope with a west aspect in a mixed forest of deciduous hardwoods and cedars. (Colors are for moist soil unless otherwise stated.)
Oi--0 to 0.5 inches; 95 percent cover of undecomposed and partially decomposed leaf litter.
A--0.5 to 1.5 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; moderate very fine subangular blocky structure; very friable; many very fine and few fine roots; slightly acid; abrupt wavy boundary.
(1 to 5 inches thick)
E--1.5 to 7 inches; light yellowish brown (10YR 6/4) silt loam, brown (10YR 5/3) near upper boundary; weak fine subangular blocky structure; very friable; many very fine and fine, common medium, and few coarse roots; very strongly acid; clear smooth boundary. (0 to 12 inches thick)
BE--7 to 10 inches; yellowish brown (10YR 5/6) silt loam; weak fine subangular blocky structure; very friable; common very fine, fine, and medium, and few coarse roots; very strongly acid; clear smooth boundary. (0 to 5 inches thick)
Bt1--10 to 17 inches; yellowish brown (10YR 5/6) silty clay loam; weak medium prismatic structure parting to moderate fine subangular blocky; friable; few very fine, common fine and medium, and few coarse roots; common faint silt coats and common faint clay films on faces of peds; very strongly acid; clear smooth boundary. (5 to 30 inches thick)
2Bt2--17 to 28 inches; strong brown (7.5YR 5/6) silty clay; weak medium prismatic structure parting to moderate fine and very fine subangular blocky; firm; few very fine, common fine, and few medium and coarse roots; common distinct clay films on faces of peds; common medium distinct brown (7.5YR 5/3) iron depletions; 5 percent limestone and chert gravel; very strongly acid. (5 to 15 inches thick)
2R--28 inches; fractured, limestone
TYPE LOCATION: Boone County, Missouri, 2,400 feet south and 200 feet east of the northwest corner of section 12, T.45 N., R. 12 W; Jefferson City NW quadrangle; lat. 38 degrees 41 minutes 41 seconds N. and long. 92 degrees 14 minutes 7 seconds W.
RANGE IN CHARACTERISTICS: Depth to a lithic contact is 20 to 40 inches. Depth to a horizon with more than 40 percent clay (lithologic discontinuity) ranges from 15 to 35 inches. Average clay content in the particle-size control section ranges from 35 to 50 percent.
The A horizon has color value of 2 to 4 and chroma of 1 to 3. Reaction is strongly acid to neutral.
The E horizon has color value of 5 or 6 and chroma of 3 or 4. Reaction is very strongly to moderately acid.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5 and chroma of 4 to 6. It is silty clay loam or silty clay. Reaction is very strongly to moderately acid.
The 2Bt horizon has hue of 10YR to 5YR, value of 4 to 6 and chroma of 3 to 8. It is silty clay or clay. Rock fragment content ranges from 0 to 15 percent. Reaction is very strongly acid to neutral.
COMPETING SERIES: These are the Ainsworth, Brevator, Haymarket, Lunt, Mirerock (T) and Welda series. All of these soils are deeper than 40 inches to a lithic contact.
GEOGRAPHIC SETTING: Bonnefemme soils are on moderately steep to steep shoulders, lower back slopes, and nose slopes of hills. They have formed in Holocene loess and residuum from limestone or dolomite that is low in chert content. Slopes range from 14 to 40 percent, and are generally plane or convex. 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 Rocheport, Clinkenbeard, Menfro, Bardley, and Winfield series. Rocheport, Winfield and Menfro soils are generally up slope from the Bonnefemme soils, are fine-silty and are deeper to a lithic contact. Clinkenbeard soils are generally down slope, have a mollic epipedon and are skeletal throughout. Bardley soils have more clay in the upper Bt horizon.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately slow and surface runoff potential is high.
USE AND VEGETATION: Most areas are in mixed forest of deciduous hardwoods, cedars, and shrubs, 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 SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Boone County, Missouri, 1998. Source of the name is Bonne Femme Creek in southern 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 7 inches (A and E horizons); argillic horizon - the zone from approximately 12 to 28 inches (Bt and 2Bt horizons).
ADDITIONAL DATA; Six pedons have been described and sampled for lab analysis at UMSCL. This pedon has sample number M9201968.