LOCATION SYENITE MO
Established Series
Rev. BLB-KDV-RLT
12/2021
SYENITE SERIES
The Syenite series consists of moderately deep, well drained. soils formed in loess and the underlying loamy residuum from granite. Permeability is moderately slow. These soils are on mountain sides ranging from 8 to 35 percent. Mean annual temperature is 57 degrees F, and mean annual precipitation is 42 inches.
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Hapludults
TYPICAL PEDON: Syenite silt loam, very bouldery - on a 14 percent northeast-facing convex slope under mixed hardwoods at 975 feet elevation. (Colors are for moist conditions unless otherwise stated.)
A--0 to 4 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; strong medium and fine granular structure; very friable; many fine and medium roots; approximately 4 percent of the surface area is covered with granite boulders; slightly acid; abrupt wavy boundary. (2 to 5 inches thick)
E--4 to 8 inches; yellowish brown (10YR 5/4) silt loam; weak medium granular structure; very friable; many fine and medium roots; moderately acid; clear smooth boundary. (0 to 10 inches thick)
Bt1--8 to 13 inches; brown (7.5YR 5/4) silt loam; moderate fine subangular blocky structure; friable; few faint dark brown clay films on faces of peds; common medium roots; very strongly acid; clear smooth boundary. (4 to 10 inches thick)
2Bt2--13 to 21 inches; brown (7.5YR 4/4) clay loam; moderate fine subangular blocky structure; firm; few distinct reddish brown clay films on faces of peds; common medium roots; l0 percent gravel; extremely acid; abrupt smooth boundary. (6 to 18 inches thick)
2BC--21 to 30 inches; brown (7.5YR 5/4) gravelly loam; many medium and coarse distinct pale brown (10YR 6/3) mottles; weak fine and very fine subangular blocky structure; firm; few medium and fine roots; 15 percent gravel; extremely acid; abrupt wavy boundary. (0 to 12 inches thick)
2R--30 inches; hard red granite.
TYPE LOCATION: St. Francois County, Missouri; about 7 miles south of Farmington; 250 feet south and 50 feet west of northeast corner of sec. 10, T.34 N., R. 5 E; Wachita Mountain, lat. 37 degrees 40 minutes 17 seconds N. and long. 90 degrees 27 minutes 36 seconds W.
RANGE IN CHARACTERISTICS: The thickness of the solum and the depth to bedrock are 20 to 40 inches. Granite boulders, stones and cobbles are prevalent and occupy from 3 to 15 percent of the land surface. The gravel content by volume of the A horizon and Bt horizon ranges from 0 to 10 percent and the gravel content of the 2Bt and 2BC horizons ranges from 5 to 30 percent. Approximately 60 percent of the coarse fragments smaller than 3 inches in diameter is less than 1/4 inch in size.
The A horizon has hue of 10YR or 7.5YR, value of 3 or 4, and chroma of 2 or 3. The E horizon has hue of 10YR or 7.5YR, value of 4 or 5 and chroma of 3 or 4. The texture of the A and E horizons is silt loam or loam and commonly is very bouldery or very stony on the surface. Reaction is slightly acid to very strongly acid.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 to 6 and chroma of 3 to 6. It is silt loam, loam, clay loam, or silty clay loam, and is strongly acid to extremely acid.
The 2Bt and 2BC horizons have hue of 10YR or 7.5YR, value of 4 to 6 and chroma of 3 or 4. Texture is sandy clay loam, clay loam, loam or their gravelly analogues. Reaction is very strongly acid or extremely acid.
A 2Cr horizon is present in some places with 5YR or 7.5YR hue, value of 3 to 8 and chroma of 4 or 5. It is compact and hard with coarse platy strata.
COMPETING SERIES: The are the
Albemarle,
Allegheny,
Allenwood,
Arendtsville,
Bedington,
Brasstown,
Bucks,
Butano,
Chester,
Chilmark,
Clymer,
Collington,
Edgemont,
Edneytown,
Elsinboro,
Eubanks,
Frankstown,
Freehold,
Gladstone,
Glenelg,
Leck Kill, Mataeke,
Meadowville,
Millstone,
Murrill,
Nixon, Pegeonroost,
Pineville,
Quakertown,
Rayne,
Shelocta,
Shouns,
Thurmont,
Ungers, and
Whiteford soils.
Pigeonroost soils have a paralithic contact at a depth of 20 to 40 inches. The rest of these soils except Quakertown and Whiteford have solum thickness or depth to bedrock or both that are greater than 40 inches. Quakertown soils have formed in residuum weathered from fine grained sandstone, sandy siltstone, and thin bedded argillite. Whiteford soils have coarse fragments of black or nearly black, very hard slate in the control section.
GEOGRAPHIC SETTING: Syenite soils are strongly sloping to steep soils on mountain sides. Slopes range from 8 to 35 percent. The soils formed in residuum from granite and possibly a thin loess deposit. Boulders and stones are characteristics of the series. Mean annual air temperature ranges from 55 to 57 degrees F, and the mean annual precipitation ranges from 40 to 45 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Irondale,
Delassus and
Loughboro soils. Irondale soils formed in very stony residuum from felsite rock and occur on foot slopes at higher elevations. Delassus soils have fragipans and formed in loess and the underlying residuum from granite. Loughboro soils are deep, poorly drained upland soils. Delassus and Loughboro soils occur on smooth to undulating ridges and divides.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is rapid. Permeability is moderately slow.
USE AND VEGETATION: These soils are in native forest of mixed hardwoods of mainly oak and small brushy prairie glades. Some areas are used for woodland grazing or cleared pasture.
DISTRIBUTION AND EXTENT: The St. Francois Mountain Area of the Eastern Ozarks, Missouri (MLRA 116C). The series is moderate in extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: INDIANAPOLIS, INDIANA
SERIES ESTABLISHED: St. Francois County, Missouri; 1979.
REMARKS: Diagnostic horizons and features recognized in this series are: ochric epipedon - the zone from the surface of the soil to a depth of 13 inches (A, E and BE horizons);
argillic horizon - the zone from approximately 13 inches to 21 inches (Bt horizon);
lithic contact - 30 inches;
udic moisture regime.
National Cooperative Soil Survey
U.S.A.