LOCATION ERIN MNInactive Series
TAXONOMIC CLASS: Fine, smectitic, mesic Glossic Hapludalfs
TYPICAL PEDON: Erin silt loam on a 12 percent convex shaped north to northwest facing wooded slope. (Colors are for moist soil unless otherwise stated.)
A--0 to 3 inches; very dark gray (10YR 3/1) silt loam; gray (10YR 5/1) dry; weak fine granular structure; very friable; slightly acid; abrupt smooth boundary. (2 to 5 inches)
E1--3 to 9 inches; dark grayish brown (10YR 4/2) silt loam; light brownish gray (10YR 6/2) dry; weak and moderate medium platy structure; very friable; medium acid; abrupt smooth boundary.
E2--9 to 12 inches; dark gray (10YR 4/1) silt loam; light gray
(10YR 6/1) dry; weak fine and medium subangular blocky structure; friable; medium acid; clear wavy boundary. (Combined thickness of E horizons is 0 to 10 inches.)
B/E--12 to 22 inches; dark grayish brown (10YR 4/2) clay loam (Bt); light brownish gray (10YR 6/2) silt coatings on peds (E); moderate and strong fine and medium subangular structure; about 3 percent coarse
fragments, mostly shale; strongly acid; clear smooth boundary. (4 to 12 inches thick)
Bt1--22 to 33 inches; olive brown (2.5Y 4/4) clay; few fine
prominent reddish brown (5YR 4/4) mottles; strong medium prismatic structure parting to strong fine and medium angular and subangular blocky; very firm; many distinct very dark grayish brown (10YR 3/2) clay films on faces of peds; about 3 percent coarse fragments, mostly shale; very strongly acid; gradual wavy boundary.
Bt2--33 to 44 inches; light olive brown (2.5Y 5/4 and 5/6) clay
loam; few fine prominent reddish brown (5YR 4/4) mottles; strong coarse prismatic structure parting to strong medium angular blocky; firm; many distinct very dark grayish brown (10YR 3/2) clay films on faces of peds; about 8 percent coarse fragments, mostly shale; very strongly acid; gradual wavy boundary.
Bt3--44 to 57 inches; light olive brown (2.5Y 5/4 and 5/6) clay
loam; common medium distinct light brownish gray (2.5Y 6/2) mottles and a few fine prominent reddish brown (5YR 4/4) mottles; strong coarse prismatic structure parting to strong medium angular blocky; firm; many distinct very dark brown (10YR 2/2) and dark grayish brown (10YR 4/2) clay films on faces of peds; about 3 percent coarse fragments, mostly shale; many fine old root channel fillings of black clayey-organic material; strongly acid; gradual wavy boundary. (Combined thickness of Bt horizons is 15 to 40 inches.)
BC--57 to 65 inches; light olive brown (2.5Y 5/4) clay loam; common medium distinct light brownish gray (2.5Y 6/2) and few fine prominent reddish brown (5YR 4/4) mottles; massive, some vertical fractures; firm; few distinct very dark brown (10YR 2/2) and dark grayish brown (10YR 4/2) clay films on faces of vertical fractures; about 3 percent coarse fragments, mostly shale; few iron and manganese oxide concretions; common old root channel fillings of black clayey-organic material; neutral; clear wavy boundary. (0 to 12 inches thick)
C--65 to 71 inches; light olive brown (2.5Y 5/4) clay loam; common fine faint light olive brown (2.5Y 5/6) and few fine prominent reddish brown (5YR 4/4) mottles; massive; some vertical fractures; firm; about 4 percent fragments, mostly shale; slightly effervescent; mildly alkaline.
TYPE LOCATION: Rice County, Minnesota; approximately 11 miles west of Faribault, Minnesota, 1320 feet south and 620 feet west of the northeast corner of section 17, T. 110 N., R. 22 W.
RANGE IN CHARACTERISTICS: The thickness of the solum and depth to lime ranges from 40 to 75 inches. The solum contains up to 10 percent coarse fragments, however, a dominant portion of this is shale that may not make the definition of a fragment. The upper 12 inches is free of coarse fragments and contains a high content of silt in some pedons.
The A horizon is typically silt loam or loam but ranges to clay loam in eroded areas. The A has value of 2 through 4 moist and 4 through 6 dry. The Ap has value of 3 or 4 moist and 6 dry.
The E has value of 4 or 5 moist and 6 or 7 dry. It is silt loam or loam.
The B/E horizon has up to 15 percent of coatings of E as interfingering into the Bt horizon. The Bt portion has properties similar to the Bt horizon.
The Bt horizon has hue of 2.5Y or 10YR value or 4 or 5 and chroma of 3 through 6. Subhorizons with high chroma mottles are not considered outside the range. Content of clay ranges from 35 to 45 percent. Textures included are clay loam, silty clay loam, clay or silty clay.
The C horizon has hue of 10YR or 2.5Y, value or 4 through 8 and chroma of 2 through 6. Texture is loam or clay loam. It contains 2 through 10 percent coarse fragments with some parts of it dominated by shale fragments.
COMPETING SERIES: No known competing series in this taxonomic class. Selected similar soils are Hortonville, Kilkenny, Lerdal, Marlette, Perrington and Shorewood series. Hortonville and Marlette series lack the clay to quality for the fine particle size class. Kilkenny and Shorewood soils lack quantative interfingering of E horizon in to the B horizon. Also, Shorewood soils lack fragments in the solum. Lerdal soils have lower chroma colors in the upper solum and are wet for longer periods. Perrington soils have thinner sola and are of mixed minerology.
GEOGRAPHIC SETTING: Erin soils are on gently sloping to very steep terrain within the end moraines of the Des Moines lobe of the late Wisconsinan glaciation. Slopes are short and are plane or convex, and have gradients of 2 to 35 percent. The regolith in the upper 3 to 10 feet is rich in shale minerals, especially in the sand to pebble sized fraction. This shale is softened and difficult to separate by particle class separates. Mean annual temperature ranges from 45 to 48 degrees F., and mean annual precipitation is about 27 to 30 inches.
DRAINAGE AND PERMEABILITY: Well drained and moderately well drained. Runoff is medium and rapid. Permeability is moderately slow.
USE AND VEGETATION: It is used for growing small grains, corn and hay. Many areas are under native deciduous forest.
DISTRIBUTION AND EXTENT: South central Minnesota. Moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Hennepin County, Minnesota, December, 1969.
REMARKS: Diagnostic horizons and features recognized are: Ochric epipedon-the zone from the surface of the soil to a depth of 13 inches (A horizons); Albic horizon - the zone from 3 to 12 inches (E1 and E2 horizons); argillic horizon-the zone from 12 inches to 57 inches (B/E, Bt1, Bt2, and Bt3 horizons); Glossoboric subgroup based on interfingering of E into Bt horizon.
ADDITIONAL DATA: Refer to S60 MINN-66-2 for data on the typifying pedon.