LOCATION BORPARK COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Borpark stony loam - rangeland. (Colors are for dry soil unless otherwise stated).
A--0 to 2 inches; brown (10YR 5/3) stony loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and nonplastic; 10 percent pebbles, 10 percent cobbles, 15 percent stones; 5 percent calcium carbonate, strongly effervescent, slightly alkaline (pH 7.6); abrupt smooth boundary. (2 to 8 inches thick)
Bt--2 to 8 inches; brown (10YR 4/3) cobbly clay loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, friable, sticky and plastic; few faint clay films on faces of peds; 10 percent pebbles, 10 percent cobbles, 5 percent stones; 5 percent calcium carbonate as disseminated lime, strongly effervescent, slightly alkaline (pH 7.6); clear smooth boundary. (5 to 10 inches thick)
Btk1--8 to 22 inches; brown (10YR 5/3) very cobbly clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; common distinct clay bridges between mineral grains; 15 percent pebbles, 20 percent cobbles, 10 percent stones; 7 percent calcium carbonate as common fine irregular filaments, strongly effervescent, slightly alkaline (pH 7.8); gradual wavy boundary.
Btk2--22 to 41 inches; pale brown (10YR 6/3) very cobbly clay loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; slightly hard, friable, sticky and plastic; common distinct clay bridges between mineral grains; 15 percent pebbles, 20 percent cobbles, 15 percent stones; 12 percent calcium carbonate as common fine irregular masses, strongly effervescent, moderately alkaline (pH 8.2); gradual wavy boundary. (combined thickness of Btk is 15 to 36 inches)
Bk--41 to 60 inches; white (10YR 8/2) extremely cobbly silt loam, pale brown (10YR 6/3) moist; massive; soft, friable, nonsticky and nonplastic; 20 percent pebbles, 30 percent cobbles, 20 percent stones; 18 percent calcium carbonate, disseminated lime, violently effervescent, moderately alkaline (pH 8.4); clear wavy boundary.
C--60 to 66 inches; light brownish gray (10YR 6/2) extremely stony sandy loam, grayish brown (10YR 5/2) moist; massive; soft, friable, nonsticky and nonplastic; 20 percent pebbles, 30 percent cobbles, 25 percent stones; 5 percent calcium carbonate, strongly effervescent, moderately alkaline (pH 8.4).
TYPE LOCATION: Mesa County, Colorado; about 1,400 feet west and 700 feet south of the northeast corner of Sec. 30, T. 9 S., R. 94 W. U.S.G.S. Hawxhurst Creek Quad. Lat. 39 degrees, 15 minutes, 13 seconds N., & Long. 107 degrees, 55 minutes, 9 seconds W.
RANGE IN CHARACTERISTICS: The Borpark soil is calcareous throughout, although the A horizon may be leached in some pedons. The mollic epipedon is 8 to 15 inches thick. The particle-size control section has 35 to 60 percent rock fragments. Rock fragments are dominantly cobble and stone size.
The A horizon has hue of 10YR or 7.5YR, value of 3 through 5 dry, 2 or 3 moist, with chroma of 1 through 3. Reaction is slightly alkaline.
The upper Bt has hue of 10YR or 7.5YR, value of 3 through 5 dry, 2 or 3 moist, with chroma of 2 or 3. The lower Bt horizon has values of 4 through 7 dry, 3 through 5 moist, and chroma of 2 through 4. Reaction is slightly alkaline or moderately alkaline. Calcium carbonate equivalent is 4 to 15 percent. Clay content is 28 to 35 percent.
The Bk and C horizons have hue of 10YR or 7.5YR, value of 5 through 8 dry, 4 through 6 moist, with chroma of 2 through 4. Reaction is moderately alkaline or strongly alkaline. Calcium carbonate equivalent is 15 to 35 percent. The percentage of calcium carbonate decreases in the C horizon. Texture is extremely cobbly silt loam, loam, or clay loam.
COMPETING SERIES: These are the Bendire (CO), Blaincreek (MT), Crackerville (MT), Curecanti (CO), Harol (UT), Harpole (UT), Higler (MT), Holter (MT), Ironco (UT), Sawbuck (MT), Shawmut (MT), Shirttail (SD), and Widtsoe (UT) soils. Bendire, Blaincreek, and Crackerville soils have bedrock at depths of 20 to 40 inches. Curecanti, Harol, Hilger, Holter, Ironco, Sawbuck, and Shirttail soils lack carbonates in the Bt horizon. In addition, Shirttail soils have bedrock at depths of 40 to 60 inches. Harpole soils have 20 to 27 percent clay in the Bt horizon and a lithologic discontinuity between 20 and 40 inches. Shawmut soils have thinner Bt horizons and have gravel that dominates the control section. Widtsoe soils have strongly cemented calcic horizons below the argillic horizon. Also, Ironco soils are greater than 50 inches thick to the base of the argillic horizon.
GEOGRAPHIC SETTING: Borpark soils are on steep stony breaks. Slopes are 40 to 75 percent. The soil formed in colluvium and glacially worked materials derived mainly from basalt and shale. Elevations are 5,800 to 7,000 feet. The mean annual precipitation is 16 to 20 inches. Mean annual temperatures range from 40 to 46 degrees F. Frost-free period ranges from 85 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fughes, Godding, and Golime soils. Fughes soils are clayey and lack stones and cobbles. Godding and Golime soils have clayey-skeletal particle-size control sections.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used as rangeland and wildlife habitat. The principal native vegetation is Gambel oak, Saskatoon serviceberry, western wheatgrass, Indian ricegrass, and junegrass.
DISTRIBUTION AND EXTENT: Mountainous areas of west central Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Mesa County (Douglas-Plateau Soil Survey Area) Colorado, 1988.
REMARKS: The soil name is a coined name from nearby Park Creek. Horizons and features recognized in this pedon are: Mollic epipedon: 0 to 8 inches; an argillic horizon: from 2 to 41 inches; skeletal particle-size control section: the zone from 2 to 22 inches; calcic horizon: the zone from approximately 40 to 60 inches. Last revised by the state 5/94.