LOCATION FIREBAUGH MOEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Fragiaquic Paleudults
TYPICAL PEDON: Firebaugh silt - on a southeast facing slightly convex slope of 3 percent in a forested area at an elevation of 905 feet. (Colors are for moist soil unless otherwise stated.)
Oi--0 to 1 inch; partially decomposed leaves, twigs, and roots.
A--1 to 4 inches; brown (10YR 4/3) silt, pale brown (10YR 6/3) dry; moderate fine granular structure; very friable; common coarse and medium roots and many very fine and fine roots; 1 percent subangular chert gravel; very strongly acid (pH 4.8); clear smooth boundary. (2 to 4 inches thick)
E--4 to 8 inches; yellowish brown (10YR 5/4) silt, very pale brown (10YR 7/4) dry; weak fine subangular blocky structure; friable; common coarse and medium roots and many very fine and fine roots; very strongly acid (pH 4.8); clear smooth boundary. (0 to 7 inches thick)
Bt1--8 to 17 inches; strong brown (7.5YR 4/6) silty clay loam; moderate very fine and fine subangular blocky structure; friable; common medium roots and many very fine and fine roots; many faint clay films on faces of peds; very strongly acid (pH 4.8); clear wavy boundary.
Bt2--17 to 21 inches; strong brown (7.5YR 5/6) silty clay loam; common fine prominent pale brown (10YR 6/3) iron depletions; moderate very fine and fine subangular blocky structure; friable; common medium roots and common very fine and fine roots; many distinct clay films on faces of peds; 1 percent subangular chert cobbles and 5 percent subangular chert gravel; very strongly acid (pH 4.7); abrupt wavy boundary. (combined thickness of the Bt horizon is 6 to 16 inches)
2Btx--21 to 36 inches; yellowish brown (10YR 5/6) very gravelly silt loam; common fine prominent grayish brown (10YR 5/2) iron depletions; weak coarse prismatic structure parting to moderate very fine and fine subangular blocky; firm; 40 percent brittle; common fine roots; few distinct pale brown (10YR 6/3) and light brownish gray (10YR 6/2) clay depletions on faces of peds and few prominent clay films on vertical faces of peds; 5 percent subangular chert cobbles and 50 percent subangular chert gravel; very strongly acid (pH 4.8); clear wavy boundary. (6 to 27 inches thick)
3Bt3--36 to 52 inches; strong brown (7.5YR 4/6) and strong brown (7.5YR 5/6) very cobbly clay; common coarse prominent red (2.5YR 4/6) masses of iron accumulation; moderate very fine and fine subangular blocky structure; firm; common very fine roots; very few distinct light gray (10YR 7/2) clay depletions on faces of peds and common prominent clay films on vertical faces of peds; 10 percent angular chert stones and 15 percent angular chert cobbles and 22 percent subangular chert gravel; very strongly acid (pH 4.7); clear wavy boundary.
3Bt4--52 to 71 inches; red (2.5YR 4/6) and strong brown (7.5YR 5/6) extremely cobbly clay; common fine and medium prominent light gray (10YR 7/2) iron depletions; moderate fine subangular blocky structure; very firm; few very fine roots; common prominent clay films on faces of peds; 10 percent angular chert stones and 30 percent angular chert cobbles and 31 percent subangular chert gravel; very strongly acid (pH 4.7).
TYPE LOCATION: Madison County, Missouri; about 10 miles south of Fredericktown; 100 feet north and 2,810 feet east of the southwest corner of section 32, T.32N., R.6E.; Cherokee Pass USGS quadrangle; latitude 37 degrees 24 minutes 23 seconds N., longitude 90 degrees 18 minutes 0 seconds W..
RANGE IN CHARACTERISTICS: Depth to the 2Btx horizon ranges from 18 to 27 inches.
A or Ap horizon
Hue 10YR
Value: 3 to 5
Chroma: 2 or 3
Fine earth: silt, silt loam
Rock fragments: 0 to 10 percent
Reaction: very strongly acid to moderately acid
E horizon
Hue 10YR
Value: 4 to 8
Chroma: 3 to 6
Fine earth: silt, silt loam
Rock fragments: 0 to 10 percent
Reaction: very strongly acid to moderately acid
Bt horizon
Hue: 10YR to 5YR
Value: 4 to 6
Chroma: 4 to 8
Fine earth: silt loam, silty clay loam, clay loam
Rock fragments: 0 to 15 percent
Reaction: very strongly acid or strongly acid
2Btx horizon
Hue: 10YR or 7.5YR
Value: 4 to 7
Chroma: 4 to 8
Fine earth: loam, silt loam, silty clay loam,
Rock fragments: 20 to 60 percent
Reaction: very strongly acid or strongly acid
3Bt horizon:
Hue: 10YR to 2.5YR
Value: 3 to 7
Chroma: 4 to 8
Fine earth: clay loam, silty clay, clay
Rock fragments: 15 to 75 percent
Reaction: very strongly acid or strongly acid
3BC horizon (where present)
Hue: 10YR to 2.5YR
Value: 3 to 6
Chroma: 6 or 8
Fine earth: clay loam, clay
Rock fragments: 0 to 40 percent
Reaction: very strongly acid or strongly acid
COMPETING SERIES: This is the Aslinger series. Aslinger soils have a 3Bt horizon that formed in alluvium and are on terraces and footslopes.
GEOGRAPHIC SETTING: Firebaugh soils are on ridgetops and sideslopes. Slopes range from 3 to 15 percent. These soils formed in a thin mantle of loess or silty sediment and the underlying loamy and clayey material weathered from cherty dolostone. Mean annual temperature is about 54 to 58 degrees F., and the mean annual precipitation is about 38 to 48 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Captina and Clarksville series. Captina soils have a fragipan and are on broader ridgetop positions. Clarksville soils are loamy-skeletal and are on backslopes at lower elevations.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is moderate in the Bt horizon and slow in the 2Btx horizon. Runoff is medium to high. These soils have a perched high water table from 1.5 to 2.5 feet from the soil surface between December and April in most years. This saturated zone is typically a few inches thick and is present for a few days or more after heavy rainfall or snowmelt.
USE AND VEGETATION: Most areas are used for timber production. Some acreage is used for grass and legume pasture or hay crops. Native vegetation was hardwoods and shortleaf pine.
DISTRIBUTION AND EXTENT: The Ozarks Highland Area (MLRA 116A) of Missouri. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Madison County, Missouri 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1) Ochric epipedon - the zone from the surface of the soil to a depth of 10 inches (A and E horizons);
2) Argillic horizon - the zone from 7 to 70 inches (Bt and 2Btx and 3Bt horizons);
3) Fragic properties - 20 to 35 inches (2Btx horizon);
4) Ultisol feature - The typical pedon has a base saturation of 37 percent at the critical depth. This is within the margin of sampling or lab error for placement into the Ultisol order.
ADDITIONAL DATA: Missouri University soil characterization laboratory number M9412334. The 3Bt horizon was split for sampling purposes.