LOCATION MAGGIN             WY+MT
Established Series
Rev. PSD
02/97

MAGGIN SERIES


The Maggin series consists of moderately deep, well drained soils formed in residuum and slopewash alluvium on rock-controlled uplands. Slopes are 2 to 30 percent. The mean annual precipitation is about 15 inches and the mean annual temperature is about 48 degrees F.

TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Haplustolls

TYPICAL PEDON: Maggin clay loam-rangeland. (Colors are for dry soil unless otherwise stated.)

A--0 to 7 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse granular structure; soft, firm, sticky and plastic; 25 percent shale fragments easily crushed, between 2 mm. and one-fourth inch in size; common fine and medium roots; medium acid (pH 5.8); clear smooth boundary. (3 to 10 inches thick)

Bw--7 to 17 inches; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure; soft, firm, sticky and plastic; 60 percent shale fragments easily crushed, between 2 mm. and one-fourth inch in size, common fine and medium roots; strongly acid (pH 5.4); gradual wavy boundary. (8 to 16 inches thick)

C--17 to 36 inches; light brownish gray (10YR 6/2) clay, dark grayish brown (10YR 4/2) moist; massive; slightly hard, firm, stick and plastic; 70 percent shale fragments easily crushed, between 2 mm. and one-fourth inch in size; common fine roots; strongly acid (pH 5.4); clear wavy boundary. (9 to 23 inches thick)

Cr--36 inches; dark gray; strongly acid; carbonaceous fissile shale.

TYPE LOCATION: Crook County, Wyoming; SW1/4, NW1/4 of sec. 33, T. 56 N., R 60 W.

RANGE IN CHARACTERISTICS: The mean annual temperature is 47 to 53 degrees F. The mean summer soil temperature is 58 to 65 degrees F. Depth to shale bedrock is 20 to 40 inches. The control section is clay, averaging between 60 and 70 percent clay. Shale fragments in the particle size control section range from 35 to 70 percent and are mainly between 2 mm. and one-fourth inch in size. They crush easily with only slight pressure. Consistence is soft or slightly hard. Maggin soils range from medium to very strongly acid.

The A horizon has hue of 10YR or 2.5Y, value of 3 through 5 dry, 2 or 3 moist, and chroma of 1 or 2. Texture is clay loam or loam. Coarse fragments of easily crushed shale fragments make up 10 to 30 percent of this horizon.

The Bw horizon has hue of 10YR or 2.5Y, value of 3 through 5 dry, 2 through 4 moist, and chroma of 1 or 2. Texture is clay. Soft shale platelets make up about 35 to 70 percent of the horizon.

The C horizon has hue of 10YR or 2.5Y, value of 4 through 6 dry, 3 or 4 moist, and chroma of 1 or 2. Texture is clay. Soft shale platelets make up about 35 to 70 percent of the horizon.

The contact to the Cr horizon is paralithic. The material beneath the contact is carbonaceous fissile shale. The low chromas in the lower part of the soil profile are inherited from this shale.

COMPETING SERIES: There are no series in the same family. Similar and related series are the Broadhurst, Graner, Grummit, and Querc. Broadhurst soils have hard or very hard consistence, and the Broadhurst and Graner soils have over 60 percent clay in the control section and lack paralithic contacts above 40 inches. Grummit soils have a paralithic contact above 20 inches. The Querc soils have argillic horizons.

GEOGRAPHIC SETTING: Maggin soils are on rolling uplands. Slopes are 2 to 30 percent. They form on residuum weathered from acid, fissile shale. The mean annual temperature is 45 to 51 degrees F. Annual precipitation is 13 to 19 inches, most of which falls in the spring and early summer. Elevation is 3,200 to 6,000 feet. The frost-free season is 110 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Broadhurst, Graner, Grummit, and Querc soils.

DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability which is due to the granulated shale platelets throughout the profile. If disturbed or utilized as construction material, the platelets break down and permeability becomes very slow.

USE AND VEGETATION: Used for rangeland and wildlife habitat. Native vegetation consists of prairie sandreed, prairie cordgrass, little bluestem, needleleaf sedge, some scattered ponderosa pine, and scrub oak. If disturbed or mismanaged, the surface breaks down, becomes compacted, and will not support this kind of vegetation.

DISTRIBUTION AND EXTENT: Northeastern Wyoming. The series is inextensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado

SERIES PROPOSED: Crook County, Wyoming; 1973. The name is a coined name.


REMARKS: Coarse fragments in the Maggin soil are composed of soft shale chips which break down upon pretreatment.
National Cooperative Soil Survey
U.S.A.