LOCATION GREYCAP            CO
Established Series
Rev. DKR/CES/WWJ
08/2006

GREYCAP SERIES


The Greycap series consists of shallow and very shallow, well drained soils that formed in residuum derived from limestone of the Greenhorn member of the Mancos Shale formation, with some sandstone eolian influence on the surface. Greycap soils are on structural benches. Slopes range from 1 to 6 percent. Mean annual precipitation is about 9 inches and the mean annual temperature is about 54 degrees F.

TAXONOMIC CLASS: Loamy, carbonatic, mesic, shallow Typic Torriorthents

TYPICAL PEDON: Greycap loam on a west facing, 2 percent slope in rangeland at an elevation of 4,950 feet. (Colors are for dry soil unless otherwise noted.) The surface is covered with 10 percent limestone parachanners.

A--0 to 2 inches; light yellowish brown (10YR 6/4) loam, yellowish brown (10YR 5/4) moist; moderate medium platy structure parting to strong very fine granular; soft, very friable, nonsticky and nonplastic; common very fine roots throughout; many very fine vesicular and interstitial pores; 44 percent calcium carbonate equivalent; 5 percent limestone parachanners; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary.

AC--2 to 6 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and medium roots throughout; many very fine dendritic tubular pores; 47 percent calcium carbonate equivalent; 1 percent limestone parachanners; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary.

Cr--6 inches; highly fractured limestone from the Greenhorn member of Mancos Shale

TYPE LOCATION: Montezuma County, Colorado; about 4 miles northeast of Four Corners Monument; Sentinel Peak Southwest, Colorado USGS quad; lat. 37 degrees 01 minutes 11.97 seconds N. and long. 108 degrees 58 minutes 21.96 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:

Soil moisture regime: Typic aridic
Mean annual soil temperature: 54 to 58 degrees F
Depth to paralithic contact: 6 to 20 inches to soft limestone

Particle-size control section (weighted average):
Clay content: 18 to 35 percent
Rock fragments: 1 to 15 percent limestone channers

A horizon:
Thickness: 1-6 inches
Hue: 10YR
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 3 or 4
Texture: loam
Clay content: 15 to 27 percent
Rock fragments: 1 to 15 percent limestone parachanners
Calcium carbonate equivalent: 30 to 45 percent
Reaction: moderately alkaline

AC or C horizon
Thickness: 4 - 16 inches
Hue: 2.5Y or 10YR
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 3 or 4
Texture: clay loam, silty clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent limestone parachanners
Calcium carbonate equivalent: 45 to 65 percent
EC (mmhos/cm): 0 to 2
Gypsum: 0 to 2 percent
Reaction: moderately alkaline

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Parent material: residuum derived from limestone, with eolian influence in the surface
Landform: structural benches
Slopes: 1 to 6 percent
Elevation: 4,600 to 5,700 feet
Mean annual temperature: 52 to 56 degrees F
Mean annual precipitation: 8 to 10 inches
Precipitation pattern: uniform with slight dip in May and June and slight increase in July and August
Frost-free period: 135 to 160 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nomad and Hope series. The Nomad soils are moderately deep to soft limestone and are on structural benches. The Hope soils are very deep and are in broad drainageways.

DRAINAGE AND PERMEABILITY: Well drained, medium or high runoff, moderately slow permeability.

USE AND VEGETATION: The Greycap soils are used for rangeland. Native vegetation is mock heather, sagebrush, fourwing saltbush, and Indian ricegrass.

DISTRIBUTION AND EXTENT: Montezuma County, Colorado, Ute Mountain Indian Reservation. MLRA 35. This series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.

SERIES ESTABLISHED: Montezuma County, Colorado, Ute Mountain Area, Colorado and New Mexico, 2005.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 0 to 16 inches.
Particle-size control section: The zone from 0 to 6 inches. (A and AC horizons)
Ochric epipedon: The zone from 0 to 6 inches. (A and AC horizons)
Lithic contact: The contact with soft limestone at 6 inches. (Cr horizon)

ADDITIONAL DATA: Calcium carbonate equivalence was determined using a field volume calcimeter. Gypsum percentage was determined with a HACH kit.

Classified according to Keys to Soil Taxonomy Ninth Edition, 2003


National Cooperative Soil Survey
U.S.A.