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

McHenry County, Illinois—Part I 27
gray (10YR 4/1) dry; weak fine granular structure;
friable; common very fine roots; neutral; abrupt
smooth boundary.
A—8 to 13 inches; black (10YR 2/1) silt loam, dark
gray (10YR 4/1) dry; moderate fine and medium
granular structure; friable; common very fine roots;
neutral; clear smooth boundary.
Bt1—13 to 18 inches; dark grayish brown (10YR 4/2)
silty clay loam; moderate fine subangular blocky
structure; friable; common very fine roots; many
distinct very dark gray (10YR 3/1) organic
coatings on faces of peds; few distinct dark
grayish brown (10YR 4/2) clay films on faces of
peds; common fine very dark gray (10YR 3/1) iron
and manganese oxide concretions throughout;
common fine distinct yellowish brown (10YR 5/6)
masses of iron accumulation in the matrix; neutral;
clear smooth boundary.
Bt2—18 to 25 inches; light olive brown (2.5Y 5/3) silty
clay loam; weak medium prismatic structure
parting to moderate fine and medium subangular
blocky; friable; common very fine roots; many
distinct dark grayish brown (10YR 4/2) clay films
on faces of peds; few distinct very dark gray
(10YR 3/1) organic coatings in root channels and
in pores; common fine very dark gray (10YR 3/1)
iron and manganese oxide concretions
throughout; common fine distinct yellowish brown
(10YR 5/6) masses of iron accumulation and gray
(10YR 6/1) iron depletions in the matrix; neutral;
clear smooth boundary.
Bt3—25 to 35 inches; light olive brown (2.5Y 5/3) silty
clay loam; moderate medium prismatic structure
parting to moderate medium subangular blocky;
friable; few very fine roots; common distinct dark
grayish brown (10YR 4/2) clay films on faces of
peds; common fine very dark gray (10YR 3/1) iron
and manganese oxide concretions throughout;
many fine distinct yellowish brown (10YR 5/6)
masses of iron accumulation in the matrix;
common fine distinct gray (10YR 6/1) iron
depletions in the matrix; neutral; clear smooth
boundary.
2Btg—35 to 43 inches; grayish brown (2.5Y 5/2) loam;
moderate medium prismatic structure; friable; few
very fine roots; few distinct dark grayish brown
(10YR 4/2) clay films on faces of peds; common
fine and medium very dark gray (10YR 3/1) iron
and manganese oxide concretions throughout;
many fine and medium prominent yellowish brown
(10YR 5/6) masses of iron accumulation in the
matrix; common fine distinct gray (10YR 6/1) iron
depletions in the matrix; slightly alkaline; clear
smooth boundary.
2Cg—43 to 60 inches; 60 percent grayish brown (2.5Y
5/2), 30 percent yellowish brown (10YR 5/6), and
10 percent gray (10YR 6/1), stratified loam and silt
loam; massive; friable; few fine very dark gray
(10YR 3/1) iron and manganese oxide concretions
throughout; 1 percent gravel; slightly effervescent;
moderately alkaline.
MLRA Series Range in Characteristics
Thickness of the mollic epipedon: 10 to 20 inches
Thickness of silty material: 24 to 40 inches
Depth to carbonates: Greater than 40 inches
Thickness of the solum: 40 to 55 inches
Ap or A horizon:
Hue—10YR
Value—2 or 3
Chroma—1 or 2
Texture—silt loam
Bt horizon:
Hue—10YR or 2.5Y
Value—4 to 6
Chroma—2 to 4
Texture—silty clay loam or silt loam
2Btg horizon:
Hue—7.5YR, 10YR, or 2.5Y
Value—4 to 6
Chroma—2 to 6
Texture—silt loam, sandy loam, loam, or clay loam
2Cg horizon:
Hue—7.5YR, 10YR, or 2.5Y
Value—4 to 6
Chroma—2 to 6
Texture—silt loam, sandy loam, loam, clay loam,
or loamy sand
149A—Brenton silt loam, 0 to 2 percent
slopes
Setting
Landform: Outwash plains, stream terraces, and till
plains
Position on the landform: Footslopes
Slope range: 0 to 2 percent
A typical soil series description with range in
characteristics is included, in alphabetical order, in this
section. Additional information specific to this map
unit, such as horizon depth and textures, is available
in the “Soil Properties” section in Part II of this
publication.