LOCATION AUXVASSE MOEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aeric Albaqualfs
TYPICAL PEDON: Auxvasse silt loam - on a 2 percent slope in unimproved pasture. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; dark brown (10YR 4/3) silt loam, pale brown (10YR 6/3) dry; weak very fine granular structure; very friable; common fine roots; many fine concretions (oxides); slightly acid; clear smooth boundary. (6 to 10 inches thick)
E--9 to 18 inches; pale brown (10YR 6/3) silt loam; moderate thin platy structure; friable; common fine roots; many fine pores and vesicles; common fine distinct yellowish brown (10YR 5/4) masses of iron accumulation in the matrix; many fine concretions (oxides); moderately acid; abrupt smooth boundary. (6 to 12 inches thick)
B/E--18 to 21 inches; yellowish brown (10YR 5/6) silty clay (Bt); strong fine subangular blocky structure; friable; many prominent light brownish gray (2.5Y 6/2) clay depletions (E) on faces of peds and as fillings in vertical cracks; common fine roots; many very fine distinct strong brown (7.5YR 5/8) masses of iron accumulation in the matrix of the Bt part; very strongly acid; abrupt smooth boundary. (0 to 3 inches thick)
Btg--21 to 31 inches; grayish brown (2.5Y 5/2) silty clay; dark yellowish brown (10YR 4/4) to yellowish brown (10YR 5/4) kneaded; moderate fine angular blocky structure; very firm; few fine roots; many faint clay films on faces of peds; many fine prominent dark yellowish brown (10YR 4/4) masses of iron accumulation in the matrix; many fine concretions (oxides); very strongly acid; clear smooth boundary. (8 to 16 inches thick)
Cg--31 to 60 inches; grayish brown (2.5Y 5/2) silty clay loam; massive; very firm; many fine prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; many fine concretions (oxides); very strongly acid.
TYPE LOCATION: Callaway County, Missouri; about 3/4 mile southwest of the town of Auxvasse, approximately 1,220 feet east and 1,940 feet north of the southwest corner, Sec. 22, T. 49 N., R. 9 W.
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon ranges from about 24 to 40 inches. The A horizon and E horizon are very strongly acid to slightly acid unless limed. The upper part of the B horizon is moderately acid to very strongly acid and the lower part of the B horizon and C horizon is very strongly acid to slightly alkaline.
The Ap horizon has color value of 4 or 5 and chroma of 2 or 3.
The E horizon has hue of 10YR or 2.5Y, value of 5 or 6 and chroma of 2 or 3. The B/E or E/B horizon has properties like the E and the Bt horizons except the chroma of the Bt part ranges from 3 to 8.
The Btg horizon has hue of 10YR or 2.5Y, value of 4 to 6 and chroma of 1 or 2. It is clay or silty clay in the upper part and ranges to silty clay loam in the lower part. Clay content averages between 40 and 60 percent. There are common to many redox features with value of 4 or 5 and chroma of 3 to 8.
The Cg horizon has hue of 10YR to 5Y, value of 4 to 6, and chroma of 1 or 2. It is silt loam or silty clay loam.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Auxvasse soils occupy nearly level stream terraces and flood plains with slope gradients of 0 to 3 percent. The soil formed in alluvium. The mean annual temperature varies from about 54 to 59 degrees F, and the mean annual precipitation varies from about 35 to 45 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Belknap, Moniteau, Racoon, Sharon and Westerville series. The poorly drained Moniteau and Racoon soils do not have abrupt textural changes between their A and B horizons and have fine-silty argillic horizons. The somewhat poorly drained Westerville and Belknap, and the well and moderately well drained Sharon soils do not have argillic horizons. All of the associated soils are on stream terrace or flood plain positions and have less clay in the series control section.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Runoff potential is low. Permeability is very slow.
USE AND VEGETATION: Most areas are used for cultivated crops, small grain or pasture. Native vegetation is mixed hardwoods.
DISTRIBUTION AND EXTENT: Central and northeast Missouri. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Knox, Monroe, and Shelby Counties, Missouri, 1973.
REMARKS: Diagnostic horizons and features recognized in this series are: ochric epipedon - the zone from the surface of the soil to about 19 inches (Ap, E, and part of B/E horizons); albic horizon - the zone from approximately 9 to 19 inches (E and part of B/E horizons); argillic horizon - the zone from approximately 19 to 31 inches (part of B/E and Btg horizons).