LOCATION RAZORBA                 CO

Established Series
Rev. LWW/GB/KLS
08/2022

RAZORBA SERIES

The Razorba series consists of very deep, well drained soils that formed in material weathered from hard, calcareous sedimentary rocks. Razorba soils are on mountain sides and have slopes of 30 to 75 percent. The average annual precipitation is about 510 mm and average annual temperature is about 3 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Pachic Haplocryolls

TYPICAL PEDON: Razorba channery loam, native woodland. (Colors are for dry soil unless otherwise noted.)

Oe--0 to 3 cm; litter of leaves, twigs, and bark in varying stages of decomposition. (0 to 8 cm thick)

A1--3 to 26 cm; dark grayish brown (10YR 4/2) channery sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable; about 20 percent fine channery fragments; slightly effervescent; moderately alkaline; clear wavy boundary.

A2--26 to 54 cm; dark grayish brown (10YR 4/2) channery sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable; about 30 percent fine channery fragments; slightly effervescent; moderately alkaline; clear wavy boundary.

A3--54 to 92 cm; dark grayish brown (10YR 4/2) channery sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable; about 30 percent fine channery fragments; slightly effervescent; moderately alkaline; clear wavy boundary. (Combined thickness of A horizons - 40 to 150 cm)

C--92 to 156 cm; grayish brown (10YR 5/2) channery sandy loam, dark grayish brown (10YR 4/2) moist; massive; soft, very friable; about 25 percent fine channery fragments; strongly effervescent; moderately alkaline.

TYPE LOCATION: Rio Blanco County, Colorado; about 35 km south of Rangely, on the east side of Texas Mountain, about 580 meters west and 580 meters south of the NE corner of Sec. 28, T. 3 S., R. 102 W. U.S.S.S. Texas Mountain quad.; Lat. 39 degrees, 45 minutes, 38 seconds N., and Long. 108 degrees, 50 minutes, 42 seconds W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 to 6 degrees C
Mean summer soil temperature--12 to 15 degrees C
Thickness of mollic epipedon--40 to 100 cm thick
Depth to lithic contact--more than 150 cm

Particle-size control section:
Clay content--12 to 18 percent
Texture class--moderately coarse
Rock fragment content--15 to 35 percent (by volume) and are mainly less than 75 mm in diameter. The lower part can contain as much as 45 percent rock fragments in some pedons.

A horizon
Value--4 or 5 dry, 2 or 3 moist
Chroma--2 or 3
Reaction--pH 7.9 to 8.4

C horizon
Value--5 or 6 dry, 4 or 5 moist
Chroma--2 or 3
Reaction--pH 7.9 to 8.4

COMPETING SERIES: These are the Aycab (NV), Cindersprings (ID), Coffeepot (NV), Coutis (WY), Earcree (ID), Foxvire (NV), Gardners Fork (UT), Hailman (UT), Moonlight (ID), Naz (ID), Shook (MT), Skyway (CO), Taral (AK), and Tosp (MT) series. Ascab soils have a paralithic contact at 60 to 100 cm. Cinderspring soils are leached of carbonates in the upper horizons and have rock fragments composed of cinders, and have cinders below 100 cm. Coffeepot soils have a paralithic contact at 100 to 150 cm. Coutis soils have less than 15 percent rock fragments and are slightly acid or neutral. Earcree and Gardners Fork soils are noncalcareous and are neutral through moderately acid. Foxvire soils lack carbonates throughout the profile. Foxvire soils lack carbonates throughout the profile. Hailman soils have a B2 horizon and a cobbly loam control section and are slightly acid or moderately acid. Naz soils have 5 to 13 percent clay and contain less than 20 percent rock fragments. Shook soils are noncalcareous in the upper horizons, have a Bw horizon, and have a high proportion of medium and coarse angular sand. Moonlight soils have cambic horizons, lack carbonates throughout, and are moderately acid to neutral. Skyway soils have a lithic contact at depths of 50 to 100 cm. Taral soils lack carbonates throughout, have a subarctic continental climate with mean annual air temperature of -5 to -3 degrees C. Topsoils lack carbonates throughout, are 100 to 150 cm deep over granitic bedrock, and average less than 15 percent rock fragments in the texture control section.

GEOGRAPHIC SETTING:
Landform--smooth to concave portions of mountain slopes which are significantly shaded from the sun
Elevation--2125 and 2550 m
Slope--30 to 75 percent
Parent material--marlstone or calcareous fine-grained sandstone or shale
Mean annual precipitation--460 to 560 mm, of which about one-half falls during the spring and summer
Mean annual temperature--3 to 5 degrees C
Frost-free season--less than 75 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

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

USE AND VEGETATION: These soils are used mainly for watershed purposes and as habitat for wildlife. The principal vegetation is Douglas-fir, serviceberry, and snowberry. Less steep or less north facing slopes also support pinyon. Lesser components of understory include Oregon grape, American vetch, elk sedge, and mountain brome.

DISTRIBUTION AND EXTENT: Razorba soils are of small extent in the mountains of northwestern Colorado and possibly adjacent parts of Utah; MLRA 48A

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Rio Blanco County, Colorado, 1979

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Thickness of mollic epipedon and pachic feature--40 to 100 cm
Texture class--coarse-loamy
Particle-size control section--25 to 100 cm (part of A1 horizon, all of A2 and A3 horizons, and part of the C horizon)

Razorba soils have a cryic temperature regime and an udic soil moisture regime with a typic subclass.

Converted to metric, updated formatting, and O horizons were updated to start at zero. 8/2022

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National Cooperative Soil Survey
U.S.A.