LOCATION MARSDEN ORTentative Series
TAXONOMIC CLASS: Fine, smectitic, frigid Typic Argixerolls
TYPICAL PEDON: Marsden silt loam - rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 8 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak thin platy and moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; many very fine roots; many very fine tubular pores; neutral (pH 6.8); clear smooth boundary. (5 to 10 inches thick)
B1t--8 to 13 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; hard, firm, sticky and plastic; common very fine roots; many very fine tubular pores; few thin clay films; few gray coatings on ped surfaces; 5 to 10 percent pebbles; neutral (pH 6.8); clear smooth boundary. (5 to 8 inches thick)
B21t--13 to 18 inches; brown (10YR 5/3) heavy clay loam, dark brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, very firm, sticky and plastic; common very fine roots; many very fine tubular pores; few moderately thick clay films; many dark brown (10YR 3/3) and gray (10YR 5/2) coatings on ped surfaces; 5 to 10 percent pebbles; neutral (pH 6.8); clear smooth boundary. (4 to 9 inches thick)
B22t--18 to 28 inches; pale brown (10YR 6/3) clay, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; very hard, very firm, very sticky and very plastic; common very fine roots; many very fine tubular pores; many moderately thick clay films; 5 to 10 percent pebbles; neutral (pH 6.8); clear smooth boundary. (8 to 14 inches thick)
B3t--28 to 36 inches; light yellowish brown (10YR 6/4) heavy clay loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; hard, firm, sticky and plastic; common very fine roots; many very fine tubular pores; few moderately thick clay films; 5 to 10 percent pebbles; neutral (pH 6.8); gradual smooth boundary. (0 to 10 inches thick)
C1--36 to 43 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; massive; hard, firm, sticky, plastic; few roots; 5 to 10 percent pebbles; neutral (pH 6.8); clear wavy boundary. (5 to 10 inches)
C2r--43 inches; soft siltstone and mudstone.
TYPE LOCATION: Grant County, Oregon. 3 miles north of Seneca on unimproved road, 0.5 miles east of U.S. Hwy. 395, SW1/4, SE1/4, sec. 15, T. 16 S., R. 31 E.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact is 40 to over 60 inches. Marsden soils are usually moist but dry in all parts between 4 and 12 inches for 60 or more consecutive days in most years. Mean annual soil temperature ranges from 43 to 47 degrees F. It has 0 to 10 percent pebbles and 35 to 50 percent clay in the textural control section.
The A1 horizon has value of 4 or 5 dry and 2 or 3 moist and chroma of 2 moist and dry.
The B2t horizon has value 5 or 6 dry and 4 moist, and chroma of 4 dry and moist. Structure is moderate and ranges from very fine to medium subangular blocky.
COMPETING SERIES: These are the Booford, Booth, Manila, Ostler and Rob Roy series. Booford soils Booth and Rob Roy soils are moderately deep to bedrock. Manila soils have hue of 7.5 YR and 5YR in the subsoil. Ostler soils have a solum of 35 to 60 inches thick.
GEOGRAPHIC SETTING: Marsden soils occur on undulating to steep slopes in and around high mountain valleys at elevations of 4,200 to 5,000 feet. The regolith consists of deep, old lakelaid sediments. Mean annual precipitation ranges from 11 to 14 inches. Mean annual temperature is about 43 degrees F. The frost-free period is less than 30 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Damon, Silvies, Calamity, Izee and the competing Fopiano soils. Damon and Silvies soils are poorly drained and have very thick black surface horizons. Calamity soils have high exchangeable sodium. Izee soils have dark colored epipedons over 20 inches thick and fine loamy 10 to 40 inch control sections.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow or medium on gentle slopes and rapid on steeper slopes. Permeability is moderately slow.
USE AND VEGETATION: These soils are used for rangeland. Native vegetation includes Idaho fescue, bluebunch wheatgrass, Sandberg bluegrass, prairie junegrass and big sagebrush.
DISTRIBUTION AND EXTENT: Marsden soils are found in and near high mountain valleys of east central Oregon. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grant County, Oregon, 1959.
REMARKS: This is an update of the IRD dated 3-28-68.
OSED scanned by SSQA. Last revised by state on 6/81.