LOCATION SAPINERO                CO

Established Series
Rev. RHM-KLS
01/2023

SAPINERO SERIES

The Sapinero series consists of deep, well drained soils that formed in residuum and/or colluvium derived from highly fractured rhyolite or rhylolitic tuff. These soils are on mesa tops and ridges. Slopes are 2 to 40 percent. Mean annual precipitation is about 410 mm, and mean annual air temperature is about 1 degree C.

TAXONOMIC CLASS: Loamy-skeletal over fragmental, mixed, superactive Typic Glossocryalfs

TYPICAL PEDON: Sapinero sandy loam - forest. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 5 cm; undecomposed organic material mainly needles, bark, twigs and leaves.

Oe--5 to 10 cm; partially decomposed organic material like that of the horizon above.

E--10 to 35 cm; light brownish gray (10YR 6/2) sandy loam, dark grayish brown (10YR 4/2) moist; weak thin platy structure that parts to very fine granules; slightly hard, very friable; slightly acid; gradual smooth boundary. (15 to 30 cm thick)

E/B--35 to 60 cm; mixed light brownish gray (10YR 6/2) and light brown (7.5YR 6/3) very stony loam (composite texture), dark grayish brown (10YR 4/2) and brown (7.5YR 5/3) moist; weak coarse subangular blocky structure that parts to fine granules; slightly hard, very friable, slightly sticky, slightly plastic; peds are hard, friable; this horizon consists of seams and nodules of clayey material like that of the underlying horizon embedded in a lighter colored matrix like that of the overlying horizon; 60 percent stones; slightly acid; gradual wavy boundary. (10 to 30 cm thick)

Bt--60 to 98 cm; light brown (7.5YR 6/3) very stony clay loam, brown (7.5YR 5/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; peds are very hard, firm; thin patchy clay films on peds and in root channels and pores; 60 percent rock fragments, mostly flagstones; slightly acid; gradual wavy boundary. (25 to 41 cm thick)

2C--98 to 162 cm; fragmental deposits of highly fractured rhyolite or rhyolitic tuff. Horizon consists principally of flagstones overlapping one another but with 3 to 5 cm cracks between the rocks that are not completely filled with fine materials.

TYPE LOCATION: Gunnison County, Colorado; The Black Mesa Experimental Pastures, Sec. 12, T. 49 N., R. 5 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--3 degrees C
Mean summer soil temperature--7 degrees C
Thickness of O horizon--at least 10 cm
Base saturation--60 to 100 percent in all subhorizons of the argillic horizon
Depth to fragmental 2C horizon--50 to 100 cm
Depth to top of argillic horizon--less than 60 cm
Depth to base of argillic horizon--43 to 100 cm
These soils are noncalcareous throughout.
Thin A horizons may be present in some pedons.
The Bt horizon typically extends to the 2C horizon, but non-fragmental C horizons occur in some pedons.

Particle-size control section:
Rock fragment content--35 to 75 percent in a major part of the solum and are mainly flagstones ranging from 250 to 1000 mm in diameter
Reaction--pH 5.6 to 7.3

E horizon
Hue--2.5Y through 7.5YR
Value--5 through 8 dry, 4 through 7 moist
Chroma--1 through 4

Bt horizon
Hue--2.5Y through 7.5YR
Value--5 through 7 dry, 4 through 6 moist
Chroma--1 through 6
Texture--very stony loam, clay loam, or sandy clay loam
Clay content--18 to 35 percent
Sand content--20 to 65 percent, with more than 15 percent being fine or coarser sand

COMPETING SERIES: These are the Kebler and Ruby series. Kebler soils have a lithic contact at depths of 50 to 100 cm. Ruby soils have mollic epipedons, lack albic horizons and have fragmental 2C horizons at depths of less than 50 cm.

GEOGRAPHIC SETTING:
Landform--mesa tops and ridges
Elevation--2900 to 3200 meters
Slope--2 to 40 or more percent
Parent material--residuum weathered from highly fractured rhyolite or rhylolitic tuff or colluvial deposits of such rock
Mean annual precipitation--410 mm, with peak periods of precipitation occurring during the spring and summer
Mean annual air temperature--1 degree C
Mean summer air temperature--7 degrees C
Frost-free period--40 to 50 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

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

USE AND VEGETATION: These soils are used as native pastureland, for forestry, and for recreation. Principal native vegetation is mainly Engelmann spruce, Douglas-fir, scattered aspen, Thurber fescue, and bluegrass.

DISTRIBUTION AND EXTENT: Sapinero soils are moderately extensive in the mountainous areas of southwest Colorado; MLRA 48A.

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

SERIES ESTABLISHED: Gunnison County, Colorado, 1974

REMARKS: Converted to metric and O horizons were updated to start at zero. Competing series section was not updated. 01/2023

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National Cooperative Soil Survey
U.S.A.