LOCATION BLAKABIN           CO
Established Series
Rev. WSH/GB/JPP
02/1999

BLAKABIN SERIES


The Blakabin series consists of very deep, well drained soils that formed in residuum and colluvium from interbedded shale and sandstone. Blakabin soils are on mountain side slopes and have slopes of 5 to 50 percent. The mean annual precipitation is about 20 inches and the mean annual temperature is about 38 degrees F.

TAXONOMIC CLASS: Fine, smectitic Ustic Haplocryolls

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

A--0 to 3 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, very friable, sticky and plastic; common very fine roots; weakly effervescent, moderately alkaline; 10 percent fine sandstone channers; clear smooth boundary. (2 to 8 inches thick)

Bw1--3 to 14 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure parting to strong fine angular blocks; hard, friable, sticky and plastic; common very fine, few fine pores and roots; weakly effervescent, moderately alkaline; 10 percent fine sandstone channers; clear wavy boundary. (6 to 12 inches thick)

Bw2--14 to 25 inches; light brownish gray (10YR 6/2) clay loam, dark grayish brown (10YR 4/2) moist; strong fine angular blocky structure; hard, firm, sticky and plastic; common very fine, and few fine pores and roots; strongly effervescent, moderately alkaline; 10 percent fine sandstone channers; clear way boundary. (0 to 14 inches thick)

Bk1--25 to 32 inches; light brownish gray (2.5Y 6/2) clay, dark grayish brown (2.5Y 4/2) moist; strong fine and medium angular blocky structure; hard, firm, sticky and plastic; common very fine and few fine pores and roots; strongly effervescent, moderately alkaline with visible secondary calcium carbonate occurring as a few fine filaments; 10 percent fine sandstone and shale channers; clear wavy boundary. (4 to 8 inches thick)

Bk2--32 to 50 inches; light brownish gray (2.5Y 6/2) clay, grayish brown (2.5Y 5/2) moist; weak fine and medium subangular blocky structure; hard, firm, sticky and plastic; common very fine and fine pores; few very fine and fine roots; violently effervescent, moderately alkaline with visible secondary calcium carbonate occurring as common fine and medium seams and soft masses; 15 percent fine sandstone and shale channers; clear wavy boundary. (14 to 20 inches thick)

Bk3--50 to 60 inches; light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, friable, sticky and plastic; common very fine pores; violently effervescent, strongly alkaline with visible secondary calcium carbonate as many fine and medium seams and soft masses; 5 percent fine sandstone and shale channers.

TYPE LOCATION: Rio Blanco County, Colorado; about 24 miles south and 4 miles east of the town of Rangely; approximately 1,200 feet south and 580 feet east of the NW corner of Sec. 3, T. 4 S., R. 101 W. U.S.G.S. Brushy Point quad.; Lat. 39 degrees, 44 minutes, 00 seconds N., and Long. 108 degrees, 43 minutes, 23 seconds W.

RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 40 to 45 degrees F; the mean summer soil temperature ranges from 55 to 59 degrees F. The depth of the uniformly calcareous material ranges from 0 to 16 inches. The mollic epipedon ranges from 8 to 16 inches thick. The particle-size control section is clay loam, silty clay loam, or light clay with 35 to 50 percent clay. Rock fragments range from 0 to 15 percent by volume throughout the profile and are sandstone and shale channers less than 3 inches in size. These soils have continuous horizons of calcium carbonate.

The A horizon has hue of 2.5Y or 10YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 or 3. Typically, it has strong granular structure, but some pedons have moderate fine subangular blocky structure. It is slightly alkaline or moderately alkaline.

The Bw horizons have hue of 2.5Y or 10YR, value of 4 through 6 dry, 3 or 4 moist, and chroma of 2 or 3. It is slightly alkaline or moderately alkaline.

The Bk horizons have hue of 2.5Y or 10YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 1 through 3. It is moderately alkaline or strongly alkaline.

COMPETING SERIES: These are the Kildor (CO) and Leaps (CO) series. Kildor soils have a paralithic contact at a depth of 20 to 40 inches. Leaps soils are noncalcareous about 40 inches and are medium acid through mildly alkaline.

GEOGRAPHIC SETTING: These soils are on mountain side slopes at elevations of 7,200 to 8,500 feet. Slopes range from 5 to 50 percent. The soil formed in fine textured calcareous residuum and colluvium from interbedded shales and sandstone. The average annual precipitation ranges from 18 to 22 inches. The frost-free season is less than 75 days. The average annual temperature ranges from 37 to 42 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kobar, Moyerson, Parachute, Razorba, Rentsac, Rhone, Vandamore, Veatch, and Waybe soils. Kobar soils lack a mollic epipedon and are less than 20 inches deep to a paralithic contact. Moyerson soils lack a mollic epipedon, have a paralithic contact at depths shallower than 20 inches, and have an average summer soil temperature greater than 59 degrees F. Parachute soils have a paralithic contact at a depth of 20 to 40 inches. Razorba soils have a mollic epipedon thicker than 16 inches and have less than 18 percent clay. Rentsac soils lack a mollic epipedon and have a lithic contact at less than 20 inches. Rhone soils have a mollic epipedon more than 16 inches thick and have less than 35 percent clay in the control section. Vandamore soils lack a mollic epipedon and have a lithic contact at a depth of 20 to 40 inches. Veatch soils have a lithic contact at a depth of 20 to 40 inches. Waybe soils lack a mollic epipedon and have a paralithic contact at a depth of less than 20 inches.

DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; slow permeability.

USE AND VEGETATION: These soils are used mainly for native rangeland or recreation. Principal native vegetation is serviceberry, Gambel oak, snowberry, scattered pinon pine, few quaking aspen, mountain brome, Letterman and Columbia needlegrasses, Idaho fescue, elk sedge, big sagebrush, rose, lupin, and other forbs.

DISTRIBUTION AND EXTENT: Mountain areas of western Colorado, and possibly adjacent parts of Wyoming. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Rio Blanco County, Colorado, 1979.

REMARKS: Diagnostic horizons and features recognized are: a mollic epipedon from 0 to 14 inches; a cambic horizon from 3 to 25 inches; continuous horizons of visible calcium carbonate, a cryic temperature regime. Last updated by the state 4/95.


National Cooperative Soil Survey
U.S.A.