LOCATION SAWFORK COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Vitrandic Argicryolls
TYPICAL PEDON: Sawfork very cobbly loam - on a 35 percent southwest- facing slope in an area of rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; grayish brown (10YR 5/2) very cobbly loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; 30 percent pebbles, 20 percent cobbles, and 5 percent stones; neutral (pH 6.8); abrupt smooth boundary. (3 to 5 inches thick)
AB--4 to 8 inches; grayish brown (10YR 5/2) very cobbly loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; 30 percent pebbles, 20 percent cobbles, and 5 percent stones; neutral (pH 7.0); abrupt wavy boundary. (0 to 4 inches thick)
Bt--8 to 14 inches; pale brown (10YR 6/3) very cobbly clay loam, dark brown (10YR 4/3) moist; moderate medium prismatic structure; hard, friable, sticky and plastic; common prominent clay films on ped faces; 30 percent pebbles, 20 percent cobbles, 5 percent stones; neutral (pH 7.2); clear wavy boundary. (5 to 18 inches thick)
BC--14 to 22 inches; pale brown (10YR 6/3) sandy clay loam, brown (10YR 4/3) moist weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; 10 percent pebbles; slightly alkaline (pH 7.4); gradual wavy boundary. (0 to 8 inches thick)
2C1--22 to 30 inches; very pale brown (10YR 7/3) loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; 10 percent angular pebble-size fragments of highly compacted ash breakable with hands; slightly effervescent; moderately alkaline (pH 8.0); clear wavy boundary.
2C2--30 to 39 inches; white (10YR 8/1) loam, light brownish gray (10YR 6/2) moist; massive; hard, friable, slightly sticky and slightly plastic; 60 percent angular pebble-size fragments of ash breakable with hands; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary.
2C3--39 to 48 inches; white (10YR 8/1) sandy loam, light brownish gray (10YR 6/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; 75 percent angular pebbles of tuff that break down easily in the hand; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (Combined thickness of the 2C horizons ranges from 20 to 40 inches.)
2Cr--48 to 52 inches; highly compacted, fragmented ash flow with few roots along fractures.
TYPE LOCATION: Fremont County, Colorado; 1,150 feet east and 550 feet south of the northwest corner of Sec. 5, T. 51 N., R. 11 E. U.S.G.S. Gribbles Park quad.; Lat. 38 degrees, 41 minutes, 33 seconds N., and Long. 105 degrees, 48 minutes, 30 seconds W.
RANGE IN CHARACTERISTICS: Depth to the paralithic contact ranges from 40 to 60 inches. The thickness of the mollic epipedon ranges from 7 to 13 inches. The mollic epipedon may include the upper part of the argillic horizon. Depth to the base of the argillic horizon ranges from 10 to 20 inches. Depth to disseminated calcareous material ranges from 5 to 25 inches. Mean annual soil temperature ranges from about 39 to 45 degrees F., and mean summer soil temperature ranges from about 51 to 58 degrees F.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. Reaction is neutral or slightly alkaline.
An AB horizon is not present in some pedons.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 through 4. Rock fragments range from 35 to 60 percent and are mainly pebbles and cobbles. The fine-earth fraction is loam, clay loam, or sandy clay loam, and averages 18 to 35 percent clay, 15 to 40 percent silt, and 30 to 60 percent sand. Reaction is neutral or slightly alkaline.
The 2C horizon has hue of 10YR through 5Y, value of 6 through 8 dry, 5 through 7 moist, and chroma of 1 through 4. Rock fragments range from 0 to 35 percent and are mainly pebbles and cobbles. This horizon has 0 to 90 percent fragments of weathered ash flow and tuff that break down easily and slake in water. The fine-earth fraction is sandy loam or loam with or without gravelly modifiers. Reaction is slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Blaine (MT), Bowen (CO), Buena Vista (CO), Chamberlain (ID), Elwood (UT), Ess (AZ), Ezbin (ID), Forner (WY), Forsey (UT), Fourme (ID), Fourmile (CO), Geertsen (UT), Hodden (CO), Hoodle (UT), Latigo (ID), Libeg (MT), Maciver (MT), Nathale (WY), Nathrop (CO), Norriston (CO), Nurkey (ID), Packer (NV), Parkview (CO), Quander (CO), Ratiopeak (MT), Scuffe (NV), Stopatoe (NV), Tahquats (ID), Teeler (WY), Thiel (MT), Winada (NV), Woodhall (CO), and Zeebar (ID) series.
Blaine, Bowen, Buena Vista, Elwood, Nathale, Nathrop, Stuffe, and Woodhall soils have a lithic contact at depths of less than 40 inches.
Chamberlain, Ess, Ezbin, Fornor, Forsey, Fourme, Fourmile, Hoodle, Latigo, Libeg, Maciver, Norriston, Nurkey, Quander, Ratiopeak, Teeler, and Zeebar soils lack bedrock at depths of 40 to 60 inches, lack lithologic discontinuity of horizons containing soft pebble-sized fragments of ash and tuff that break easily in the hands, and have more than 35 percent rock fragments in all horizons below the Bt horizon. Fourme and Fourmile soils also have sandy-skeletal substratum.
Geertsen soils have a lithic contact of limestone at 40 to 60 inches, lack a lithologic discontinuity of horizons containing soft ash and tuff fragments, and have more than 35 percent rock fragments below the Bt horizon.
Hodden and Norriston soils lack bedrock above 60 inches and have sandy-skeletal 2C substratum.
Maciver soils also have mean annual precipitation of 15 to 22 inches, and have moist spring months.
Packer soils have a lithologic discontinuity in the argillic horizon and lack a paralithic contact at 40 to 60 inches.
Parkview, Stopatoe, and Winada soils have a paralithic contact at depths of 20 to 40 inches.
Tahquats soils are moderately acid, lack a lithologic discontinuity, and have more than 35 percent rock fragments below the Bt horizon.
Thiel soils have a lithologic discontinuity of sandy-skeletal material at 20 to 40 inches.
GEOGRAPHIC SETTING: Sawfork soils are on fan terrace side slopes. Slopes range from 8 to 50 percent. The soil formed in colluvium and residuum derived dominantly from ash flow and tuff. Elevation ranges from 8,800 to 10,000 feet. The mean annual precipitation ranges from about 11 to 16 inches, and most delineations are in areas with mean annual precipitation of 14 inches or less. This is less than the precipitation of competing series except for the geographically associated Hodden series. Mean annual temperature ranges from 38 to 44 degrees F. The average frost-free period is about 55 to 85 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gebson and Morset soils and the competing Hodden and Thiel soils. Gebson and Morset soils have less than 35 percent rock fragments throughout.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderate to moderately slow permeability.
USE AND VEGETATION: These soils are used for rangeland. Principal native vegetation consists of mountain muhly, Arizona fescue, slimstem muhly, blue grama, western wheatgrass, prairie junegrass, and fringed sagebrush.
DISTRIBUTION AND EXTENT: Intermontane basins of central Colorado in areas of relatively low precipitation. The series is of limited extent.
MLRA OFFICE RESPONSIBLE: Lakewood, Colorado
SERIES ESTABLISHED: Fremont County (Fremont County Area), Colorado, 1988.
REMARKS: Diagnostic horizons and features recognized are: a mollic epipedon from 0 to 8 inches; an argillic horizon from 8 to 14 inches; over 35 percent rock fragments in the texture control section; a lithologic discontinuity at 22 inches; an ustic moisture regime; and a cryic temperature regime. Last updated by the state 8/95.