LOCATION GAASTRA MI+WIEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, active, frigid Argic Endoaquods
TYPICAL PEDON: Gaastra silt loam - with a southeast-facing convex slope of 2 percent - forested. (Colors are for moist soil unless otherwise stated.)
Oa--0 to 1 inch; black (N 2/0) well decomposed leaf litter; weak fine granular structure; very friable; abrupt smooth boundary. (1 to 2 inches thick)
A--1 to 4 inches; dark brown (7.5YR 3/2) silt loam, brown (7.5YR 4/2) dry; moderate medium granular structure; friable; many fine and medium roots; about 2 percent gravel; moderately acid; abrupt smooth boundary. (2 to 4 inches thick)
E--4 to 6 inches; brown (7.5YR 5/2) silt loam, pinkish gray (7.5YR 6/2) dry; common fine distinct strong brown (7.5YR 4/6) mottles; moderate medium subangular blocky structure parting to weak thin platy; friable; common fine vesicular pores; common fine and medium roots; about 2 percent gravel; moderately acid; clear wavy boundary. (0 to 4 inches thick)
Bs--6 to 14 inches; dark brown (7.5YR 4/4) silt loam; common fine prominent yellowish red (5YR 4/6) and common medium prominent dark grayish brown (10YR 4/2) mottles; weak medium subangular blocky structure; friable; common fine vesicular pores; common fine and medium roots; about 2 percent gravel; moderately acid; clear smooth boundary. (5 to 8 inches thick)
E'--14 to 22 inches; brown (10YR 5/3) silt loam, light gray (10YR 7/2) dry; many coarse distinct brown (7.5YR 5/2) and many medium distinct yellowish brown (10YR 5/6) mottles; moderate thick platy structure; slightly compact in place; friable; common fine vesicular pores; few fine roots; about 2 percent gravel; moderately acid; clear wavy boundary. (2 to 8 inches thick)
Bt--22 to 37 inches; dark yellowish brown (10YR 4/4) silt loam; many coarse prominent brown (7.5YR 5/2) and few medium prominent yellowish red (5YR 4/6) mottles; weak coarse subangular blocky structure parting to weak thick platy; slightly compact in place; friable; common fine vesicular pores; common distinct reddish brown (5YR 4/4) clay films in pores and on faces of peds; about 2 percent gravel; moderately acid; gradual wavy boundary. (10 to 16 inches thick)
BC--37 to 51 inches; dark brown (7.5YR 4/4) silt loam; many medium distinct brown (7.5YR 5/2) and common medium distinct strong brown (7.5YR 4/6) mottles; weak coarse subangular blocky structure; slightly compact in place; friable; common fine vesicular pores; about 2 percent gravel; moderately acid; gradual wavy boundary. (0 to 15 inches thick)
C--51 to 60 inches; reddish brown (5YR 4/4) silt loam; common medium distinct strong brown (7.5YR 4/6) and few fine distinct brown (7.5YR 5/2) mottles; massive; slightly compact in place; friable; common fine vesicular pores; about 2 percent gravel; moderately acid.
TYPE LOCATION: Iron County, Michigan; about 1 mile west of the village of Gaastra; 1,650 feet east and 2,050 feet north of the southwest corner of sec. 11, T. 42 N., R. 35 W.
RANGE IN CHARACTERISTICS: Unless otherwise stated depth ranges in this paragraph are measured from the mineral surface. Solum thickness ranges from 26 to 55 inches. Rock fragments range from 0 to 5 percent throughout the profile. Stones covering the surface range from less than 0.01 to 0.1 percent.
The A horizon has hue of 10YR to 5YR ; value of 2 or 3; and chroma of 1 or 2. Where present, the Ap horizon has 10YR or 7.5YR hue; value of 3 to 5; and chroma of 2 or 3.
The E horizon has hue of 10YR to 5YR; value of 4 to 6, and chroma of 1 or 2. The A and E horizons are dominantly silt loam but include very fine sandy loam and loamy very fine sand. Reaction of the A and E horizon ranges from very strongly acid to slightly acid.
Some pedons have Bhs horizons with hue of 2.5YR to 7.5YR, with value and chroma of 3. The Bs horizon, or Bs1 horizon has hue of 2.5YR to 7.5YR; value of 3 or 4; and chroma of 4. Some pedons have Bs2 horizons with hue of 2.5YR to 10YR, value of 4 or 5 and chroma of 4.It is silt loam or very fine sandy loam. The Bhs and Bs horizons range from very strongly acid to moderately acid, and the Bs2 horizon ranges from very strongly acid to slightly acid.
The E' horizon has hue of 5YR to 10YR; value of 4 or 5; and chroma of 2 or 3. It is silt loam, very fine sandy loam, or sandy loam. Some pedons have E/B or B/E horizons or both. Reaction of the E', E/B or B/e horizon ranges from very strongly acid to slightly acid.
The Bt horizon has hue of 5YR to 10YR; value of 4 or 5; and chroma of 3 to 6. It is silt loam, very fine sandy loam, or fine sandy loam. Some pedons with B/E horizons do not have Bt horizons. Reaction of the Bt horizon ranges from strongly acid to slightly acid. In some pedons the lower part of the Bt horizon ranges to neutral.
The BC horizon has hue of 10YR to 5YR, value of 4 or 5 and chroma of 4 to 6. It is silt loam or very fine sandy loam. Reaction ranges from strongly acid to slightly acid, but in some pedons it ranges to neutral.
The C horizon has hue of 5YR to 10YR; value of 4 to 6; and chroma of 3 to 6. It is silt loam, very fine sandy loam, or fine sandy loam. Some pedons are stratified with thin strata of very fine sand or fine sand. The C horizon ranges from strongly acid to neutral.
COMPETING SERIES: These are the Assinins, Belding, Charlevoix, Coral, Richter, Riggsville, and Zeba series in the same family. Assinins and Riggsville soils have sand, loamy sand or loamy fine sand textures in the upper 20 inches of the solum. Belding, Charlevoix, Coral, and Richter, soils formed in calcareous materials and contain free carbonates within 60 inches. In addition, Belding soils contain more than 28 percent clay in the argillic and 2C horizons. Zeba soils have bedrock within depths of 20 to 40 inches.
GEOGRAPHIC SETTING: Gaastra soils formed in silty and loamy glaciofluvial deposits and are on level to gently sloping ground moraines and glacial lake basins. Slopes range from 0 to 4 percent. Mean annual precipitation is 26 to 33 inches; and the mean annual temperature is about 41 to 45 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the well drained or moderately well drained coarse-silty Fence soils and poorly drained fine-silty Auburndale soils. Other well drained soils include Goodman, Stambaugh, and Wabeno (T) soils. Goodman soils have a silty layer 24 to 40 inches thick overlying sandy loam till; and Stambaugh soils have a thin silty layer overlying outwash sand and gravel at depths between 20 to 40 inches. Wabeno soils formed primarily in sandy loam till.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Depth to an apparent seasonal high water table ranges from 1 to 2 feet. Runoff is slow. Permeability is moderately slow.
USE AND VEGETATION: Nearly all areas of Gaastra soils are wooded. Main species include red maple, American elm, quaking aspen, white ash, white spruce, and balsam fir. Other areas are used for hay or pasture.
DISTRIBUTION AND EXTENT: Upper Peninsula of Michigan and northern Wisconsin. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Iron County, Michigan, 1930.
REMARKS: Diagnostic horizons and features recognized in the pedon are: ochric epipedon - the zone from the surface to 3 inches (A horizon); albic horizon - the zone from 3 to 5 inches and from 13 to 21 inches (E and E' horizons); spodic horizon - the zone from 5 to 13 inches (Bs horizon); argillic horizon - the zone from 21 to 36 inches (Bt horizon).
ADDITIONAL DATA: Soil Interpretation Record No.: MI0069; MI0501 (STONY SURFACE).