Soil Survey of McHenry County, Illinois Part I - Soil Data Mart

46 Soil Survey of
Taxonomic classification: Fine-silty, mixed, mesic
Typic Endoaquolls
Typical Pedon for MLRA 95B
Typical pedon of Dunham silty clay loam, 0 to 2
percent slopes, 939 feet south and 81 feet west of the
center of sec. 15, T. 45 N., R. 5 E.
Ap—0 to 6 inches; black (N 2.5/0) silty clay loam, dark
gray (10YR 4/1) dry; weak fine subangular blocky
structure parting to moderate fine and medium
granular; friable; common very fine roots; neutral;
clear smooth boundary.
A—6 to 12 inches; black (N 2.5/0) silty clay loam, dark
grayish brown (10YR 4/2) dry; weak medium
subangular blocky structure parting to moderate
fine and medium granular; friable; common very
fine roots; moderately acid; abrupt smooth
boundary.
BAg—12 to 15 inches; dark grayish brown (2.5Y 4/2)
silty clay loam; weak fine and medium subangular
blocky structure; friable; common very fine roots;
common distinct very dark gray (2.5Y 3/1) organic
coatings on faces of peds and in pores; few fine
strong brown (7.5YR 5/6) very weakly cemented
iron oxide concretions throughout; common fine
distinct olive brown (2.5Y 4/4) masses of iron
accumulation in the matrix; moderately acid; clear
smooth boundary.
Btg1—15 to 24 inches; grayish brown (2.5Y 5/2) silty
clay loam; weak medium prismatic structure
parting to moderate fine and medium subangular
blocky; firm; common very fine roots; common
distinct dark grayish brown (2.5Y 4/2) clay films on
faces of peds; very few distinct very dark gray
(2.5Y 3/1) organic coatings in root channels and in
pores; common fine black (10YR 2/1) very weakly
cemented iron and manganese oxide concretions
throughout; few fine strong brown (7.5YR 5/6)
very weakly cemented iron oxide concretions
throughout; common medium prominent yellowish
brown (10YR 5/6) and common fine and medium
distinct light olive brown (2.5Y 5/4) masses of iron
accumulation in the matrix; slightly acid; gradual
smooth boundary.
Btg2—24 to 31 inches; grayish brown (2.5Y 5/2) silty
clay loam; moderate medium prismatic structure
parting to moderate medium angular blocky; firm;
few very fine roots; few distinct dark grayish
brown (2.5Y 4/2) clay films on faces of peds; very
few distinct very dark grayish brown (2.5Y 3/2)
organic coatings in root channels and in pores;
few fine dark brown (7.5YR 3/4) very weakly
cemented iron oxide concretions throughout;
common medium prominent strong brown (7.5YR
5/6) masses of iron accumulation in the matrix;
slightly acid; clear smooth boundary.
Btg3—31 to 35 inches; grayish brown (2.5Y 5/2) silty
clay loam; weak medium prismatic structure
parting to moderate medium subangular blocky;
firm; few very fine roots; few distinct dark grayish
brown (2.5Y 4/2) clay films on faces of peds; very
few distinct very dark grayish brown (2.5Y 3/2)
organic coatings in root channels and in pores;
many medium and coarse prominent strong brown
(7.5YR 5/6) masses of iron accumulation in the
matrix; 1 percent gravel; neutral; clear smooth
boundary.
2Btg4—35 to 39 inches; olive gray (5Y 4/2) clay loam;
weak medium subangular blocky structure; friable;
few very fine roots; few distinct olive gray (5Y 4/2)
clay films on faces of peds; very few distinct dark
olive gray (5Y 3/2) organic coatings in root
channels and in pores; many medium and coarse
prominent strong brown (7.5YR 5/6) masses of
iron accumulation in the matrix; 3 percent gravel;
neutral; abrupt smooth boundary.
3Cg—39 to 44 inches; olive gray (5Y 5/2) gravelly
sandy loam; massive; very friable; few very fine
roots; common fine prominent strong brown
(7.5YR 4/6) masses of iron accumulation in the
matrix; common fine faint light olive gray (5Y 6/2)
iron depletions in the matrix; 25 percent gravel;
strongly effervescent; slightly alkaline; clear
smooth boundary.
3C—44 to 60 inches; brown (10YR 5/3) gravelly loamy
sand and gravelly loamy fine sand; single grain;
loose; few very fine roots; common fine and
medium distinct yellowish brown (10YR 5/6)
masses of iron accumulation in the matrix;
common fine and medium faint grayish brown
(10YR 5/2) iron depletions in the matrix; 25
percent gravel; strongly effervescent; slightly
alkaline.
MLRA Series Range in Characteristics
Thickness of the mollic epipedon: 10 to 20 inches
Thickness of silty material: 24 to 50 inches
Depth to sandy and gravelly deposits: 32 to 55 inches
Depth to carbonates: 30 to 50 inches
Thickness of the solum: 36 to 55 inches
Ap or A horizon:
Hue—10YR, 2.5Y, or N
Value—2 or 3
Chroma—0 to 2
Texture—silty clay loam or silt loam
Btg horizon:
Hue—10YR, 2.5Y, 5Y, or N