LOCATION PAGAYVAY COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, mesic Ustifluventic Haplocambids
TYPICAL PEDON: Pagayvay extremely gravelly coarse sandy loam, 1 to 6 percent slopes, on a south facing, 4 percent slope in juniper and pinyon woodland at an elevation of 5912 feet. (Colors are for dry soil unless otherwise noted.) When described on 7/14/2003 the soil was dry to 60 inches.
A1--0 to 1 inches; yellowish brown (10YR 5/4) extremely gravelly coarse sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine granular structure; soft, very friable, nonsticky, nonplastic; 50 percent gravel, 20 percent cobbles, 10 percent stones and 5 percent boulders; strongly effervescent; slightly alkaline (pH 7.4); abrupt smooth boundary. (1 to 6 inches thick)
A2--1 to 3 inches; yellowish brown (10YR 5/4) extremely cobbly coarse sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine platy structure; soft, very friable,, nonsticky, nonplastic; common fine, and common medium roots throughout; 40 percent gravel, 30 percent cobbles,10 percent stones, and 5 percent boulders; strongly effervescent; slightly alkaline (pH 7.4); gradual smooth boundary. (0 to 6 inches thick)
Bk1--3 to 15 inches; yellowish brown (10YR 5/4) stratified extremely cobbly coarse sandy loam, dark yellowish brown (10YR 4/4) moist; 8 percent clay; structureless single grain; loose, nonsticky, nonplastic; common medium roots throughout; common very thin irregular carbonate masses on bottom of rock fragments; 3 percent calcium carbonate; 40 percent gravel, 30 percent cobbles, 10 percent stones, and 5 percent boulders; strongly effervescent; slightly alkaline (pH 7.4); gradual wavy boundary. (10 to 30 inches thick)
Bk2--15 to 60 inches; light yellowish brown (10YR 6/4) stratified extremely cobbly coarse sandy loam, yellowish brown (10YR 5/4) moist; structureless single grain; loose, nonsticky, nonplastic; common medium roots throughout; many thin irregular carbonate masses on bottom of rock fragments; 4 percent calcium carbonate; 40 percent gravel, 30 percent cobbles, 10 percent stones, and 5 percent boulders; strongly effervescent; slightly alkaline (pH 7.8).
TYPE LOCATION: Montezuma County, Colorado; about 5 miles west of Towaoc; located in an unsectionalized area; Mariano Wash East USGS quad; lat. 37 degrees 10 minutes 29.3 seconds N. and long. 108 degrees 49 minutes 38.1 seconds W., NAD83
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is ustic aridic.
Mean annual soil temperature: 52 to 54 degrees F
Depth to secondary calcium carbonate: 2 to 20 inches
Particle-size control section (weighted average):
Clay content: 5 to 10 percent
Sand content: 55 to 80 percent
Rock fragment content: 35 to 90 percent
A horizon:
Hue: 7.5YR to 2.5Y
Value: 5 or 6, 3 to 5 moist
Chroma: 2 to 4
Texture, fine earth fraction: coarse sandy loam or sandy loam
Clay content: 5 to 15 percent
Rock fragment content: 15 to 90 percent
Calcium carbonate equivalent: 0 to 3 percent
EC (mmhos/cm): 0 to 4
Gypsum content: 0 to a trace percent
SAR: 0 to 5
Reaction: slightly alkaline or moderately alkaline
Bk horizon:
Hue: 7.5YR to 2.5Y
Value: 5 or 6, 4 or 5 moist
Chroma: 2 to 4
Texture, fine earth fraction: stratified coarse sandy loam, sandy loam or loamy sand
Clay content: 5 to 10 percent
Rock fragment content: 35 to 90 percent
Calcium carbonate equivalent: 1 to 5 percent
EC (mmhos/cm): 0 to 4
Gypsum content: 0 to a trace percent
SAR: 0 to 5
Reaction: slightly alkaline or moderately alkaline
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Parent material: alluvium derived from diorite
Landform: floodplains and flood plain steps
Slopes: 1 to 6 percent
Elevation: 5,400 to 6,200 feet
Mean annual temperature: 50 to 52 degrees F
Mean annual precipitation: 10 to 13 inches
Precipitation pattern: Uniform with slight dip in May and June and slight increase in July and August.
Frost-free period: 120 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Katzine soils and Tupuyci series. The Katzine soils have a calcic horizon and are on fans. The Tupuyci soils have less development and are on floodplains.
DRAINAGE AND PERMEABILITY: Excessively drained, negligible runoff, very rapid permeability, and rare flooding for very brief periods during the summer and fall from thunderstorms.
USE AND VEGETATION: The area is used for livestock grazing. Vegetation consists of a thin overstory of Utah juniper with very sparse understory vegetation of sage and grasses. Potential native vegetation is mainly Utah juniper, Wyoming big sagebrush, muttongrass, Indian ricegrass, galleta, and cliffrose.
DISTRIBUTION AND EXTENT: Area surrounding Sleeping Ute Mountain, Montezuma County, Colorado; MLRA 36; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Montezuma County, Colorado, Ute Mountain Area, Colorado and New Mexico, 2005. Pagayvay (pah-GA-va) is the Ute word for crossing water.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 40 inches. (parts of the Bk1 and Bk2 horizons)
Ochric epipedon: The zone from 0 to 3 inches. (A horizons)
Cambic horizon: The zone from 3 to 60 inches. (Bk1 and Bk2 horizons) Based on presence of pedogenic carbonate.
Ustifluventic feature an irregular decrease in organic carbon is inferred from the landscape position and accompanying flooding.
Source of carbonates is believed to be from carbonatic dust from surrounding areas.
The cambic horizon qualifies because of the increase in carbonates in the Bk2 horizon in relation to the Bk1 horizon.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Keys to Soil Taxonomy Ninth Edition, 2003