LOCATION FULCHER COEstablished Series
TAXONOMIC CLASS: Fine, smectitic Pachic Argicryolls
TYPICAL PEDON: Fulcher cobbly loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 inches; grayish brown (10YR 5/2) cobbly loam, very dark grayish brown (10YR 3/2) strong firm crumb structure; soft, very friable; 15 percent cobbles; mildly alkaline (pH 7.4) clear smooth boundary. (4 to 6 inches thick)
A2--5 to 11 inches; grayish brown (10YR 5/2) very cobbly loam very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure that parts to strong fine crumbs; soft, very friable; 35 percent cobbles; mildly alkaline (pH 7.6); clear smooth boundary. (3 to 10 inches thick)
BA--11 to 17 inches; brown (10YR 5/3) cobbly light clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure that parts to moderate fine subangular blocks; slightly hard, very friable; peds are hard; few thin waxy patches on faces of peds; 15 percent cobbles; mildly alkaline (pH 7.6); gradual wavy boundary. (3 to 5 inches thick)
Bt1--17 to 37 inches; brown (10YR 5/3) cobbly heavy clay loam, dark brown (10YR 4/3) moist; strong medium angular blocky structure; slightly hard, friable, sticky, plastic; peds are extremely hard; moderate continuous wax-like coatings on faces of peds; wax-like coatings to root channels; wax-like coatings on underside of rock fragments; 15 percent cobbles; mildly alkaline (pH 7.6) clear wavy boundary. (6 to 30 inches thick)
Bk1--37 to 42 inches; pale brown (10YR 6/3) cobbly sandy clay loam, dark brown (10YR 4/3) moist; weak medium subangular blocky structure; hard, friable; peds are very hard; thin glossy patches on faces of peds; discontinuous wax-like coatings in root channels; 15 percent cobbles; visible secondary carbonate occurring as small concretions, and as coatings on cobble fragments; calcareous; moderately alkaline (pH 8.0); gradual wavy boundary. (4 to 6 inches thick)
Bk2--42 to 50 inches; light brownish gray (10YR 6/2) cobbly sandy clay loam, dark grayish brown (10YR 4/2) moist; massive, hard, friable; 15 percent cobbles; visible secondary calcium carbonate occurring as concretions in thin seams and streaks, and as coatings on rock fragments; calcareous; moderately alkaline (pH 8.2).
TYPE LOCATION: Rio Grand County Colorado; NE 1/4 of Sec. 12, T. 37 N., R. 6 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 40 degrees F. and mean summer soil temperature is 54 degrees F. The solum ranges from 20 to more than 50 inches thick. Depth to the base of the argillic horizon and depth to secondary calcium carbonate and/or sulfate accumulation range from 17 to 50 inches. The soils range from slightly acid to moderately alkaline. The argillic horizon averages 10 to 35 percent fine or coarser sand and 35 to 60 percent clay. Rock fragments in the solum and C horizons above a depth of 40 inches range from 0 to 35 percent. Hue ranges from 5Y through 7.5YR except some pedons have thin subhorizons with hue redder than 7.5YR. The lower part of the 10 to 40 inch section is loam, sandy loam, or sandy clay loam, and has 18 to 35 percent clay and more than 50 percent coarser than very fine sand.
COMPETING SERIES: These are the Burnette, Friana, Luna, Mayflower, Paulson, and Skutum series. Burnette soils have silty clay loam, silty clay, or clay C horizons that contain less than 50 percent coarser than very fine sand. Friana and Kutum soila are noncalcareous throughout. Luna and Mayflower soils have a paralithic contact at some point between depths of 20 and 40 inches. Paulson soils have 5YR or redder hue in the argillic horizon.
GEOGRAPHIC SETTING: Fulcher soils are on gently to moderately steeply sloping mountainsides and alluvial fans. Slopes typically range from 2 to 10 percent. The soils formed in thick, calcareous, medium to moderately fine textured parent materials weathered primarily from rhyolite, andesite, and trachite. At the type location the average annual precipitation is 12 inches with peak periods of precipitation in the spring and early summer. Mean annual temperature is 40 degrees F. and mean summer temperature is 55 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Embargo and Seitz soils. Embargo soils have more than 35 percent rock fragments in the control section. Seitz soils lack a mollic epipedon, have an albic horizon, and have more than 35 percent rock fragments in the control section.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used principally as native pastureland. Principal native plants are Indian ricegrass, junegrass, and western wheatgrass.
DISTRIBUTION AND EXTENT: Foothills bordering the San Luis Valley in south-central Colorado. The series is of small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Rio Grande County, Colorado, 1972.
REMARKS: Last updated by the State 11/73.