LOCATION HOOVERS COTentative Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Lithic Haplocalcids
TYPICAL PEDON: Hoovers very flaggy loam, 4 percent slope at an elevation of 5,645 feet in rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches (0 to 15 cm); brown (7.5YR 5/4) very flaggy loam, brown (7.5YR 4/4) moist; moderate fine granular structure; soft, very friable, nonsticky and slightly plastic; few fine and very fine roots; 5 percent calcium carbonate equivalent, strongly effervescent; 20 percent channers, 30 percent flagstones; moderately alkaline (pH 8.4); clear wavy boundary. (2 to 6 inches thick)
Bk1--6 to 14 inches (15 to 36 cm); pale brown (10YR 6/3) very flaggy clay loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; very few very fine roots; 5 percent calcium carbonate segregated as seams and pendants on rock fragments, 20 percent calcium carbonate equivalent, violently effervescent; 25 percent channers, 30 percent flagstones; moderately alkaline (pH 8.4); clear wavy boundary.
Bk2--14 to 18 inches (36 to 46 cm); light gray (10YR 7/2) very flaggy clay loam, grayish brown (10YR 5/2) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; 8 percent calcium carbonate segregated as seams and pendants on rock fragments, 20 percent calcium carbonate equivalent, violently effervescent; 20 percent channers, 25 percent flagstones; strongly alkaline (pH 8.6); abrupt wavy boundary. (Total thickness of the Bk horizons is 6 to 18 inches.)
R--18 inches (46 cm); unweathered sandstone bedrock.
TYPE LOCATION: Montrose County, Colorado; about 650 feet east and 1,700 feet south of the northwest corner of section 16, T. 50 N., R. 11 W. Latitude 38 degrees, 36 minutes 6 seconds N, longitude 108 degrees, 6 minutes 43 seconds W. NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is affected by precipitation that is evenly distributed throughout the year, with the exception of a slight increase in the spring and a significant increase in late summer; typic aridic moisture regime.
Mean annual soil temperature: 51 to 53 degrees F
Depth to lithic contact: 10 to 20 inches to sandstone
Depth to secondary calcium carbonate: 4 to 6 inches
Depth to calcic horizon: 4 to 6 inches
Particle-size control section (weighted average):
Clay content: 20 to 34 percent
Rock fragments: 35 to 60 percent sandstone channers and flagstones
A horizon:
Hue: 7.5YR or 10YR
Value: 4 to 7 dry, 3 to 6 moist
Chroma: 3 to 6, dry or moist
Clay content: 15 to 26 percent
Rock fragments: 15 to 35 percent sandstone channers; 5 to 30 percent sandstone flagstones
Calcium carbonate equivalent: 0 to 10 percent
Reaction: moderately alkaline
Bk horizon:
Hue: 7.5YR to 2.5Y
Value: 6 to 8 dry, 4 to 6 moist
Chroma: 1 to 4 dry or moist
Texture: very flaggy clay loam, very channery loam
Clay content: 23 to 34 percent
Rock fragments: 20 to 50 percent sandstone channers; 5 to 30 percent sandstone flagstones
Calcium carbonate equivalent: 18 to 25 percent
Gypsum content: 0 to 4 percent (mostly just above bedrock contact)
Reaction: moderately to strongly alkaline
COMPETING SERIES: These are the Crotoncanyon and Rochpah series. The Crotoncanyon and Rochpah series have mean annual soil temperatures greater than 53 degrees F
GEOGRAPHIC SETTING:
Parent material: loamy slope alluvium derived from sandstone and shale over loamy residuum derived from sandstone
Landform: dipslopes on cuestas and summits on mesas
Slopes: 1 to 15 percent
Elevation: 5,000 to 5,700 feet
Mean annual temperature: 49 to 51 degrees F
Mean annual precipitation: 10 to 12 inches
Relative effective annual precipitation: 8 to 10 inches
Precipitation pattern: The soil moisture control section is affected by precipitation that is evenly distributed throughout the year, with the exception of a slight increase in the spring and a significant increase in late summer.
Freeze-free period: 140 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Roatcap series. Roatcap soils have bedrock between 20 and 40 inches and have a gypsic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate to moderately slow permeability.
USE AND VEGETATION: These soils are used principally for livestock grazing. Native vegetation consists of galleta, saline wildrye, Indian ricegrass, and shadscale.
DISTRIBUTION AND EXTENT: Eastern edge of the Uncompahgre Plateau in Western Colorado; LRR D, MLRA 36; minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Montrose County, Colorado, 1986, Ridgway Soil Survey Area. The name is taken from a nearby community and quad sheet name.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 18 inches (25 to 46 cm). (Bk1 and Bk2 horizons)
Ochric epipedon: The zone from 0 to 6 inches (0 to 15 cm). (A horizon)
Calcic horizon: The zone from 6 to 18 inches (15 to 46 cm). (Bk1 and Bk2 horizons)
Lithic contact: The contact with sandstone at 18 inches (46 cm). (R layer)
The classification was changed from Lithic Ustic Haplocalcids to Lithic Haplocalcids April 2004 because the vegetation indicated a drier regime than what was predicted from the precipitation in the area. The soil moisture regime is now considered to be typic aridic.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Ninth edition, 2003.