LOCATION LANYON IAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Endoaquolls
TYPICAL PEDON: Lanyon silty clay, in a large depression, in a cultivated field, at an elevation of about 346 meters above sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 18 centimeters; black (N 2/0) silty clay, very dark gray (10YR 3/1) dry; weak and moderate fine granular and very fine subangular blocky structure; friable; neutral; abrupt smooth boundary.
A--18 to 33 centimeters; black (5Y 2/1) silty clay, dark gray (10YR 4/1) dry; moderate very fine subangular blocky structure; firm; few fine faint very dark grayish brown (2.5Y 3/2) redoximorphic concentrations; few fine faint dark gray (N 4/0) redoximorphic depletions; slightly alkaline; abrupt smooth boundary. (Combined thickness of the A horizon is 20 to 40 centimeters.)
BA--33 to 41 centimeters; very dark gray (5Y 3/1) and dark grayish brown (2.5Y 4/2) silty clay, olive gray (5Y 5/2) dry; weak medium prismatic structure parting to weak fine subangular blocky; firm; common medium distinct olive (5Y 4/3) redoximorphic concentrations; many very fine snail shell fragments; strongly effervescent; moderately alkaline; clear smooth boundary. (0 to 10 centimeters thick)
Bg1--41 to 51 centimeters; olive gray (5Y 4/2), very dark gray (5Y 3/1), and dark gray (5Y 4/1) silty clay; weak medium prismatic structure parting to weak fine subangular blocky; firm; few coarse distinct light olive brown (2.5Y 5/4) redoximorphic concentrations; common snail shell fragments; strongly effervescent; moderately alkaline; gradual smooth boundary.
Bg2--51 to 64 centimeters; dark gray (5Y 4/1) and olive gray (5Y 4/2) silty clay; weak fine and medium prismatic structure parting to weak fine subangular blocky; firm; few medium prominent brown (7.5YR 4/4) redoximorphic concentrations; strongly effervescent; moderately alkaline; gradual smooth boundary. (Combined thickness of the Bg horizon is 15 to 40 centimeters.)
Bkg1--64 to 117 centimeters; dark gray (5Y 4/1) silty clay; weak fine and medium prismatic structure parting to weak fine subangular blocky; firm; few fine prominent black (10YR 2/1) iron-manganese concretions; few coarse prominent white (10YR 8/1) masses of calcium carbonate; common fine distinct olive (5Y 4/3) redoximorphic concentrations; common snail shell fragments; strongly effervescent; moderately alkaline; gradual smooth boundary.
Bkg2--117 to 132 centimeters; dark gray (5Y 4/1) silty clay loam; weak fine and medium prismatic structure; friable; few fine prominent black (10YR 2/1) iron-manganese concretions; few medium prominent gray (10YR 6/1) calcium carbonate concretions; common medium prominent light olive brown (2.5Y 5/4) redoximorphic concentrations; strongly effervescent; moderately alkaline; abrupt smooth boundary. (Combined thickness of the Bkg horizon is 45 to 100 centimeters.)
2Bkg3--132 to 152 centimeters; dark gray (5Y 4/1) clay loam; weak medium prismatic structure; friable; few thin strata of sand; common fine prominent black (10YR 2/1) iron-manganese concretions; many medium prominent light olive brown (2.5Y 5/4) redoximorphic concentrations; about 5 percent rock fragments; strongly effervescent; moderately alkaline; gradual smooth boundary. (10 to 30 centimeters thick)
2BCg--152 to 200 centimeters; dark gray (5Y 4/1) loam; weak coarse prismatic structure; firm; many prominent red (2.5YR 4/6) iron coats, and common prominent black (10YR 2/1) iron-manganese coats on faces of peds; common medium prominent reddish brown (5YR 5/4) redoximorphic concentrations; about 6 percent rock fragments; slightly effervescent; slightly alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 103-Central Iowa and Minnesota Till Prairies, Webster County, Iowa subset; about 2 miles east and 3 miles south of Harcourt; located about 15 feet west and 1,120 feet south of the northeast corner of section 31, T. 86 N., R. 28 W.; USGS Lanyon topographic quadrangle; lat. 42 degrees 13 minutes 22 seconds N. and long. 94 degrees 8 minutes 44 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon--20 to 50 centimeters
Depth to carbonates--30 to 50 centimeters
Depth to till--100 to 150 centimeters
Clay content of the particle-size control section (weighted average)--38 to 45 percent
Sand content of the particle-size control section (weighted average)--less than 15 percent
Ap or A horizon:
Hue--10YR to 5Y or is neutral
Value--2
Chroma--0 or 1
Texture--silty clay or silty clay loam
Clay content--30 to 45 percent
Sand content--less than 15 percent
Rock fragment content--0 percent
Reaction--neutral or slightly alkaline
AB or BA horizon (if present):
Hue--10YR to 5Y
Value--3 or 4
Chroma--1 or 2
Texture--silty clay or silty clay loam
Clay content--35 to 60 percent
Sand content--less than 15 percent
Rock fragment content--0 percent
Reaction--slightly alkaline or moderately alkaline
Bg and Bkg horizon:
Hue--2.5Y or 5Y
Value--3 to 6
Chroma--1 or 2
Texture--silty clay or silty clay loam
Clay content--35 to 60 percent
Sand content--less than 15 percent
Rock fragment content--0 percent
Reaction--slightly alkaline or moderately alkaline
2Bkg, 2BCg or 2Cg (when present) horizon:
Hue--5Y
Value--4 or 5
Chroma--1 or 2
Texture--loam or clay loam
Clay content--10 to 38 percent
Sand content--30 to 45 percent
Rock fragment content--2 to 10 percent
Reaction--slightly alkaline or moderately alkaline
Moist bulk density--1.60 to 1.75 g/cc
COMPETING SERIES: These are the
Carlow,
Chequest,
Cove,
Fults,
Kalona,
Kings,
Mackerlake,
Marna,
Moline,
Rosedell,
Streator,
Titus,
Waldorf, and
Woodbury series.
Carlow--do not have carbonates within a depth of 150 centimeters
Chequest--do not have carbonates within a depth of 150 centimeters
Cove--have a clay content that averages 50 to 60 percent in the particle-size control section
Fults--do not have carbonates within a depth of 150 centimeters
Kalona--do not have rock fragments in the series control section
Kings--do not have rock fragments in the series control section
Mackerlake--do not have rock fragments in the series control section
Marna--do not have carbonates within a depth of 66 centimeters
Moline--have a clay content that averages 45 to 60 percent in the particle-size control section
Rosedell--do not have rock fragments in the lower third of the series control section
Streator--do not have carbonates within a depth of 89 centimeters
Titus--do not have carbonates in the upper third of the series control section
Waldorf--do not have carbonates within a depth of 66 centimeters
Woodbury--do not have carbonates within a depth of 90 centimeters
GEOGRAPHIC SETTING:
Parent material--100 to 150 centimeters of lacustrine sediments and in the underlying till
Landform--broad depressions within the late Wisconsin glacial drift plain
Slope--0 to 1 percent
Elevation--300 to 400 meters above sea level
Mean annual air temperature--6 to 10 degrees C
Mean annual precipitation--585 to 890 millimeters
Frost-free period--155 to 200 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Brownton,
Guckeen,
Marna, and
Wacousta soils.
Brownton--are at slightly higher landscape positions and are calcareous in all parts between depths of 25 and 50 centimeters
Guckeen--are at slightly higher landscape positions and have a sand content that averages 15 to 35 percent in the particle-size control section
Marna--are at slightly higher landscape positions and do not have carbonates within a depth of 66 centimeters
Wacousta--are in landscape positions similar to those of the Lanyon soils and have a clay content that averages 24 to 35 percent in the particle-size control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--very poorly drained--in an undrained condition, a frequently saturated zone occurs at the surface to a depth of 0.3 meters during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Saturated hydraulic conductivity--0.10 to 10.00 micrometers per second in the lacustrine sediments and 1.00 to 14.00 micrometers per second in the underlying till
Ponding--frequently ponded for long duration
USE AND VEGETATION:
Where drained, Lanyon soils are cultivated. The principal crops are corn, soybeans, oats, and legume hay. The natural vegetation is marsh grasses, sedges, and other grasses tolerant of excessive wetness.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Western lake section
MLRA--Central Iowa and Minnesota Till Prairies (103)
LRR M; north-central Iowa
Extent--small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Webster County, Iowa, 1969.
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters;
series control section--the zone from the surface to a depth of 150 centimeters.
Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 41 centimeters (Ap, A, and BA horizons);
cambic horizon--the zone from a depth of 41 to 200 centimeters (Bg1, Bg2, Bkg1, Bkg2, 2Bkg3, and 2BCg horizons);
aquic moisture regime.
With carbonates so significant in this soil, the question arises about calcareous class, but carbonates are not present in all parts between depths of 25 and 50 centimeters.
Classification was changed from Typic Endoaquolls to Vertic Endoaquolls in 3/2004, based on linear extensibility of 6.0 to 8.9 percent within a depth of 100 centimeters.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.