LOCATION MARCOTT MTEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Aquertic Haplustolls
TYPICAL PEDON: Marcott silty clay, abandoned cropland. (Colors are for dry soil unless otherwise noted)
Apz--0 to 8 inches; gray (10YR 5/1) silty clay, black (10YR 2/1) moist; weak medium and fine subangular blocky structure parting to moderate very fine granular; slightly hard, friable, sticky and plastic; many fine and very fine roots and common medium roots; less than 1 percent pebbles; disseminated lime; common masses and seams of salts; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (6 to 15 inches thick)
Bz1--8 to 12 inches; light brownish gray (10YR 6/2) silty clay, dark grayish brown (10YR 4/2) moist; weak medium and coarse prismatic structure parting to moderate very fine subangular blocky; slightly hard, friable, very sticky and plastic; common very fine, fine, and medium roots; many medium, fine, and very fine pores; common very dark grayish brown organic staining on peds; disseminated lime; few fine masses and seams of salts; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary.
Bz2--12 to 20 inches; light gray (2.5Y 7/2) silty clay, grayish brown (2.5Y 5/2) moist; weak coarse prismatic structure parting to moderate very fine subangular blocky; very hard, friable, very sticky and plastic; common fine and very fine roots; many very fine and fine pores and few medium pores; disseminated lime; few fine masses and seams of salt; strongly effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (Combined Bz horizons 5 to 16 inches thick)
Bkz1--20 to 25 inches; light gray (2.5Y 7/2) silty clay, grayish brown (2.5Y 5/2) moist; moderate fine and subangular blocky structure; extremely hard, firm, sticky and very plastic; common fine and very fine roots; many fine and very fine pores and few medium pores; less than 1 percent pebbles; common fine and medium masses of lime; common fine seams of salt; strongly effervescent; moderately alkaline (pH 8.4); gradual wavy boundary.
Bkz2--25 to 33 inches; light gray (2.5Y 7/2) silty clay, grayish brown (2.5Y 5/2) moist; common fine and very fine faint gray (10YR 6/1) redox depletions; weak fine and very fine subangular blocky structure; extremely hard, firm, sticky and plastic; common fine and very fine roots; many fine and very fine pores and few medium pores; less than 1 percent pebbles; common fine and medium soft masses of lime; common fine and medium seams of salt; strongly effervescent; moderately alkaline (pH 8.4); gradual wavy boundary.
Bkz3--33 to 42 inches; light gray (2.5Y 7/2) clay, dark gray (10YR 4/1) moist; many medium distinct light olive brown (2.5Y 5/6) redox concentrations; massive; extremely hard, firm, sticky and plastic; few fine and very fine roots; common fine and very fine pores; 5 percent pebbles; common fine and medium soft masses of lime; common fine and medium seams of salt; strongly effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (Combined Bkz horizons 13 to 49 inches thick)
2C--42 to 66 inches; light gray (2.5Y 7/2) extremely gravelly sandy clay loam, grayish brown (2.5Y 5/2) moist; massive; very hard, very friable, slightly sticky and slightly plastic; few fine and very fine pores; 70 percent pebbles, 5 percent cobbles; strongly effervescent; moderately alkaline (pH 8.4). (0 to 25 inches thick)
TYPE LOCATION: Fergus County, Montana; 2,000 feet west and 660 feet north of the SE corner of sec. 18, T. 18 N., R. 14 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 15 inches.
Depth to Bk horizon - 12 to 24 inches.
Depth to 2C horizon - 36 to 60 inches.
Depth to seasonal water table - 24 to 60 inches.
Gypsum- few to common masses are allowed.
Apz horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 3, 4, or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Texture: silty clay loam or silty clay
Clay content: 30 to 50 percent
Rock fragments: 0 to 5 percent pebbles
EC: 2 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm
SAR: 0 to 20
Reaction: pH 6.6 to 8.4
Bz horizons - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, 6, or 7 dry; 3, 4, or 5 moist
Chroma: 1, 2, or 3
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 5 percent pebbles
EC: 2 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm
SAR: 0 to 25
Calcium carbonate equivalent: 1 to 12 percent
Reaction: pH 6.6 to 8.4
Bkz horizons - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 1, 2, or 3
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles; 0 to 10 percent pebbles
EC: 2 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm
SAR: 0 to 30
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.4 to 9.0
2C horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 1, 2, or 3
Texture: loam or sandy clay loam
Clay content: 10 to 30 percent
Rock fragments: 0 to 80 percent--0 to 10 percent cobbles; 0 to 70 percent pebbles
EC: 2 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm
SAR: 0 to 20
Reaction: pH 7.4 to 9.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - alluvial fans; floodplains; stream terraces.
Elevation - 2,800 to 5,400 feet.
Slope- 0 to 4 percent.
Parent material - clayey alluvium from shale, limestone, and sandstone.
Climate - long, cold winters; moist springs; and hot summers.
Mean annual precipitation -12 to 19 inches.
Mean annual air temperature - 39 to 45 degrees F.
Frost-free period - 70 to 125 days.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Slow permeability. Runoff is low or medium depending on slope.
USE AND VEGETATION: Marcott soils are used for pasture, hayland, and rangeland. Potential native vegetation is mainly tufted hairgrass, prairie cordgrass, basin wildrye, Nuttall alkaligrass, western wheatgrass, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Marcott soils are moderately extensive in central and north-central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Fergus County, Montana, 1979.
REMARKS: Soil interpretation record: MT0327, MT1285, MT1336, MT8071.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 8 inches (Apz horizon); cambic horizon - the zone from 8 inches to 20 inches (Bz1 and Bz2 horizons); horizon of carbonate and salt accumulation - the zone from 20 to 42 inches (Bkz1, Bkz2, Bkz3 horizons); discontinuity - from 42 to 66 inches (2C horizon); particle-size control section - the zone from 10 to 40 inches (Bz1, Bz2, Bkz1, Bkz2, part of Bkz3 horizon). Marcott soils have an ustic moisture regime and a frigid temperature regime.
ADDITIONAL DATA: Laboratory sample S88MT-077-1228.