LOCATION THUNDERBAY MI

Established Series
Rev. BPH-TEW-MLK
08/2012

THUNDERBAY SERIES

The Thunderbay series consists of very deep, poorly drained soils formed in loamy and sandy alluvium on flood plains. Slope ranges from 0 to 2 percent. Mean annual precipitation is about 737 mm (29 inches), and mean annual temperature is about 6.7 degrees C (44 degrees F).

TAXONOMIC CLASS: Coarse-loamy, mixed, semiactive, frigid Fluvaquentic Endoaquolls

TYPICAL PEDON: Thunderbay very fine sandy loam, on a 1 percent slope in a forested area on a flood plain. (Colors are for moist soil unless otherwise stated.)

A1--0 to 18 cm (7 inches); black (10YR 2/1) broken and crushed, very fine sandy loam, very dark gray (10YR 3/1) dry; moderate medium granular structure; friable; many fine and common medium roots; very slightly effervescent; slightly alkaline; abrupt smooth boundary.

A2--18 to 36 cm (7 to 14 inches); black (10YR 2/1) broken, very dark grayish brown (10YR 3/2) crushed, very fine sandy loam, dark grayish brown (10YR 4/2) dry; moderate medium granular structure; friable; many fine roots; many medium prominent strong brown (7.5YR 4/6) masses of oxidized iron in the matrix; slightly alkaline; abrupt smooth boundary. [Combined thickness of the A horizon is 25 to 53 cm (10 to 21 inches).]

Cg1--36 to 48 cm (14 to 19 inches); dark gray (5Y 4/1) loam; weak medium subangular blocky structure; friable; common fine roots; many medium prominent strong brown (7.5YR 4/6) masses of oxidized iron in the matrix; about 5 percent of horizon consists of thin strata of brown (10YR 5/3) sand; slightly alkaline; abrupt smooth boundary. [10 to 25 cm (4 to 10 inches) thick]

Cg2--48 to 61 cm (19 to 24 inches); very dark gray (10YR 3/1) silt loam stratified with brown (10YR 5/3) sand; weak medium platy structure; friable; few fine roots; common fine prominent strong brown (7.5YR 4/6) masses of oxidized iron in the matrix; slightly alkaline; abrupt smooth boundary. [13 to 38 cm (5 to 15 inches) thick]

Cg3--61 to 79 cm (24 to 31 inches); grayish brown (10YR 5/2) sand; single grain; loose; few fine roots; common medium faint brown (10YR 5/3) and few medium prominent strong brown (7.5YR 4/6) masses of oxidized iron in the matrix; moderately alkaline; abrupt smooth boundary. [0 to 20 cm (8 inches) thick]

Cg4--79 to 203 cm (31 to 80 inches); greenish gray (5GY 5/1) sand; single grain; loose; few fine prominent strong brown (7.5YR 4/6) masses of oxidized iron in the matrix; moderately alkaline.

TYPE LOCATION: Alpena County, Michigan; 6 miles west and 4 miles south of Alpena; 50 feet south and 2,400 feet west of the northeast corner of sec. 14, T. 30 N., R. 7 E.; USGS Lake Winyah, Michigan topographic quadrangle; lat. 45 degrees 00 minutes 15.28 seconds N. and long. 83 degrees 33 minutes 18.66 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon: 25 to 53 cm (10 to 21 inches)
Thickness of the upper loamy material: 51 to 102 cm (20 to 40 inches)
Depth to carbonates: 0 to 203 cm (80 inches) and occurs irregularly throughout the profile
Organic carbon: an irregular decrease of organic matter with depth
Rock fragment content: 0 to 2 percent in the loamy layers and 0 to 20 percent in the sandy layers

A horizon:
Hue: 10YR or 2.5Y
Value: 2, 2.5, or 3
Chroma: 1 or 2
Redoximorphic features: prominent redox concentrations are present in the lower part of the mollic epipedon
Texture: very fine sandy loam
Reaction: neutral or slightly alkaline

Cg horizon:
Hue: 5YR, 10YR, 2.5Y, 5Y, or 5GY
Value: 3 to 5
Chroma: 1 or 2
Texture: silt loam or loam, or stratified loam and silt loam in the upper part; the lower part is generally sand but includes stratified layers of loam and silt loam
Reaction: slightly or moderately alkaline

Some pedons have gravelly sand below 127 cm (50 inches).

COMPETING SERIES: There are no other series in the same family.

GEOGRAPHIC SETTING: Thunderbay soils are on flood plains. Slope ranges from 0 to 2 percent. These soils formed in loamy and sandy alluvium. Mean annual precipitation ranges from 686 to 813 mm (27 to 32 inches). Mean annual temperature ranges from 6.1 to 8.3 degrees C (43 to 46 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Colonville, Bamfield, Au Gres, and Springport soils. The somewhat poorly drained Colonville soils are on similar topographic position. The well drained Bamfield soils, the somewhat poorly drained Au Gres soils, and the clayey Springport soils are adjacent soils.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. Depth to the top of a seasonal high water table ranges from the surface to 30 cm (1 foot) below the surface for sometime during the year. They flood at some time in most years. The potential for surface runoff is negligible. Saturated hydraulic conductivity is high in the upper loamy material and high or very high in the lower sandy material. Permeability is moderately rapid in the upper loamy material and rapid in the lower sandy material.

USE AND VEGETATION: Most areas of Thunderbay soils are forested. Black ash and red maple are the dominant trees.

DISTRIBUTION AND EXTENT: MLRA 94A in northeast Michigan. This series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: AMHERST, MASSACHUSETTS

SERIES ESTABLISHED: Alpena County, Michigan, 1994.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: from the surface to a depth of 36 cm (14 inches) (A1 and A2 horizons).
Aquic conditions: prominent redoximorphic features in the lower part of the mollic epipedon and in all underlying horizons
Particle-size control section: averages coarse loamy and the textural transition within the Cg horizons is more than 12.5 cm thick.
Irregular decrease in organic carbon content.

ADDITIONAL DATA: Soil Interpretation Record: MI0735.

National Cooperative Soil Survey
U.S.A.