LOCATION GRATIOT MIEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Fragiaquods
TYPICAL PEDON: Gratiot very cobbly fine sandy loam, on a northwest-facing slope of 1 percent, in a forested area. (Colors are for moist soil unless otherwise stated.)
Oa--0 to 1 inch; dark reddish brown (5YR 3/3) well decomposed forest litter; strongly acid; abrupt smooth boundary. (0 to 2 inches thick)
A--1 to 4 inches; black (5YR 2.5/1) very cobbly fine sandy loam, dark reddish brown (5YR 3/2) dry; medium coarse granular structure; friable; many very fine to medium and common coarse and very coarse roots; 25 percent gravel, 15 percent cobbles, 2 percent stones; strongly acid; abrupt wavy boundary. (0 to 6 inches thick)
Bhs--4 to 7 inches; dark reddish brown (5YR 3/2) very cobbly loamy sand; moderate medium subangular blocky structure; friable; many very fine to medium and common coarse and very coarse roots; 34 percent gravel, 15 percent cobbles, 2 percent stones; strongly acid; clear wavy boundary. (0 to 6 inches thick)
Bs1--7 to 12 inches; dark reddish brown (5YR 3/4) very cobbly loamy sand; moderate medium subangular blocky structure; friable; many very fine, common fine and medium roots; few medium prominent yellowish red (5YR 4/6) masses of iron accumulation; 34 percent gravel, 15 percent cobbles, 2 percent stones; strongly acid; clear wavy boundary.
Bs2--12 to 20 inches; reddish brown (5YR 4/4) very cobbly fine sandy loam; weak medium platy parting to weak medium subangular blocky structure; friable; many very fine, common fine and medium roots; many medium prominent yellowish red (5YR 4/6) and yellowish red (5YR 5/8) masses of iron accumulation; 24 percent gravel, 13 percent cobbles, 2 percent stones; strongly acid; clear wavy boundary. (Combined thickness of the Bs horizon ranges from 6 to 18 inches.)
B/Ex--20 to 30 inches; about 75 percent reddish brown (5YR 4/4) cobbly fine sandy loam (Bt), surrounding reddish brown (5YR 5/3) cobbly loamy fine sand (E), reddish gray (5YR 5/2) dry; moderate thick platy structure; firm; few faint reddish brown (5YR 4/4) clay bridges between sand grains; few very fine and fine roots; many medium prominent yellowish red (5YR 4/6) and yellowish red (5YR 5/8) masses of iron accumulation; 21 percent gravel, 10 percent cobbles, 2 percent stones; slightly acid; clear wavy boundary. (10 to 22 inches thick)
C1--30 to 36 inches; reddish brown (5YR 4/3) cobbly fine sandy loam; massive; friable; few very fine and fine roots; common medium prominent yellowish red (5YR 4/6) and yellowish red (5YR 5/8) masses of iron accumulation; 10 percent gravel, 7 percent cobbles, 2 percent stones; neutral. (0 to 15 inches thick)
C2--36 to 80 inches; reddish brown (5YR 4/3) cobbly fine sandy loam; massive; friable; 10 percent gravel, 6 percent cobbles, 1 percent stones; strongly effervescent; strongly alkaline.
TYPE LOCATION: Keweenaw County, Michigan; located about 1,700 feet north and 2,200 feet east of the southwest corner of section 35, T. 58 N., R. 31 W.; USGS Eagle Harbor topographic quadrangle; lat. 47 degrees 22 minutes 36 seconds N. and long. 88 degrees 12 minutes 2 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: Thickness of the solum is 25 to 52 inches. Depth to the fragipan ranges from 15 to 30 inches. The solum ranges from very strongly acid to slightly acid and the C horizon ranges from slightly acid to strongly alkaline. Gravel content ranges from 10 to 30 percent in the A horizon, 15 to 45 percent in the E, Bhs, and Bs horizons and 5 to 35 percent throughout the remainder of the pedon. Cobbles and stones range from 5 to 30 percent above the fragipan and 0 to 20 percent in the remainder of the pedon. The particle-size control section averages more than 35 percent rock fragments.
The O horizon has hue of 5YR or 7.5YR, value of 2, and chroma of 1 or 2.
The A horizon has hue of 5YR, 7.5YR, or 10YR; value of 2 or 3; and chroma of 1 or 2. The A horizon is the gravelly, very gravelly, cobbly, or very cobbly analogs of fine sandy loam or loamy fine sand.
The E horizon, where present, has hue of 5YR, 7.5YR, or 10YR; value of 4 to 6; and chroma of 2 or 3. It is the gravelly, very gravelly, cobbly, or very cobbly analogs of fine sandy loam or loamy fine sand.
The Bhs horizons have hue of 5YR, 7.5YR, or 10YR; value of 2 to 3; and chroma of 2 to 3.
The Bs horizons have hue of 5YR, 7.5YR, or 10YR; value of 3 to 4; and chroma of 4 to 5.horizons are the very gravelly, extremely gravelly, very cobbly, or extremely cobbly analogs of fine sandy loam, loamy sand, or loamy fine sand.
The B part of the B/Ex horizon has hue of 5YR, 7.5YR, or 10YR; value of 4 or 5, and chroma of 2 or 4. It is very fine sandy loam, fine sandy loam or sandy loam or the gravelly or cobbly analogs of these textures. The E part has hue of 5YR, 7.5YR, or 10YR, value of 4 or 5 and chroma of 2 or 3. It is fine sandy loam, loamy fine sand, sandy loam, loamy sand or the gravelly or cobbly analogs of these textures.
The C horizons have hue of 5YR, 7.5YR, or 10YR, value of 4 or 5, and chroma of 2 to 4. The C horizons are loamy sand, loamy fine sand, fine sandy loam, sandy loam or the gravelly or cobbly analogs of these textures.
COMPETING SERIES: There are none. The closely related Net series average less than 35 percent coarse fragments in the particle-size control section and do not allow calcareous material in the substratum.
GEOGRAPHIC SETTING: Gratiot soils are in slightly depressional areas and drainageways on moraines. They formed in cobbly and gravelly loamy material over loamy and sandy till. Slope ranges from 0 to 4 percent. Mean annual precipitation ranges from 30 to 36 inches, and mean annual air temperature ranges from 40 to 45 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dishno, Montreal, Paavola, and Sabattis soils. The very deep Montreal and Paavola soils, and the deep Dishno soils are moderately well drained and occur on slightly higher landscape positions on knolls, ridges, and hillslopes. The poorly drained Sabattis soils are in lower depressions and drainageways.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Surface runoff is negligible to low. Permeability is moderate above the fragipan, very slow in the fragipan, and moderately rapid or moderate below the fragipan.
USE AND VEGETATION: Most areas are forested with red maple, balsam fir, yellow birch, northern white cedar, and white spruce being the major species. Other areas were formerly pastured and are now idle.
DISTRIBUTION AND EXTENT: Northwestern part of the Upper Peninsula of Michigan, primarily on the Keweenaw Peninsula. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota; MLRA SSO 10-8 (Marquette, Michigan).
SERIES ESTABLISHED: Keweenaw County, Michigan, 2004. Source of name is a lake in Keweenaw County.
REMARKS: Diagnostic horizons and features recognized in the pedon include:
Ochric epipedon--1 to 4 inches (A horizon);
Spodic horizon--4 to 20 inches (Bhs, Bs1, Bs2 horizons);
Fragipan--20 to 30 inches (B/Ex horizon);
Glossic horizon--20 to 30 inches (B/Ex horizon).
The B/Ex horizon does not meet the requirements for an argillic horizon.
Only series status, responsibility, and scrivener's errors changed - 3/09.