LOCATION QUAZAR                  CO+NM UT WY

Established Series
Rev. JPP/TWH/KLS
03/2018

QUAZAR SERIES


The Quazar series consist of very deep, well drained soils formed in alluvium, slope alluvium, colluvium derived from volcanic rock. These soils are on alluvial fans, pediments, fan remnants and mountain slopes. Slopes range from 5 to 65 percent. Mean annual precipitation is about 762 mm and the mean annual air temperature is about 2.2 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Argicryolls

TYPICAL PEDON: Quazar very stony loam, on a north facing 25 percent alluvial fan slope on rangeland at an elevation of 2,957 meters. (colors are for dry soil unless otherwise noted. When described on August 30, 1983, the soil was moist throughout.)

A1--0 to 13 cm; dark grayish brown (10YR 4/2) very stony loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; soft, very friable, nonsticky and nonplastic; 15 percent gravel, 20 percent cobbles, 20 percent stones; neutral (pH 6.8); clear smooth boundary.

A2--13 to 25 cm; dark grayish brown (10YR 4/2) very stony loam, black (10YR 2/1) moist; weak medium granular structure; soft, very friable, nonsticky and nonplastic; 15 percent gravel, 20 percent cobbles, 20 percent stones; neutral (pH 6.6); clear smooth boundary. (combined thickness of A1, A2 horizons - 25 to 38 cm)

Bt--25 to 76 cm; pinkish gray (7.5YR 6/2) extremely cobbly clay loam, brown (7.5YR 4/2) moist; weak medium subangular blocky structure parting to moderate medium granular; slightly hard, firm, sticky and plastic; common distinct clay films on faces of peds; 20 percent gravel, 30 percent cobbles, 10 percent stones; neutral (pH 6.6); clear smooth boundary. (48 to 142 cm thick)

2C--76 to 168 cm; light brown (7.5YR 6/4) extremely cobbly sandy loam, brown (7.5YR 5/4) moist; single grain; loose, nonsticky and nonplastic; 30 percent gravel, 30 percent cobbles, 15 percent stones; slightly acid (pH 6.4). (0 to 95 cm thick)

TYPE LOCATION: Hinsdale County, Colorado; about 10 kilometers west of Lake City, Colorado; within an unsectionized area of BLM land, estimated to be in Section 5, T. 43 N., R. 5 W.; USGS Uncompahgre Peak topographic quadrangle; Lat. 38 degrees, 00 minutes, 35 seconds N. and Long. 107 degrees, 26 minutes, 06 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 1.7 to 6.1 degrees C.
Thickness of mollic epipedon: 25 to 38 cm
Depth to top of argillic horizon: 25 to 38 cm
Lithology of rock fragments: andesite, rhyolite, breccia, or tuff

Particle-size control section:
Clay content: 25 to 34 percent clay
Rock fragment content: 40 to 70 percent
Reaction (pH): 6.1 to 7.8

A horizon
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry, 1 to 3 moist
Texture: loam, silt loam
Rock fragments: 20 to 55 percent total rock fragments; 5 to 45 percent gravel, 5 to 30 percent cobbles, 0 to 25 percent stones.
Reaction (pH): 6.1 to 7.3

Bt horizon
Hue: 5YR to 10YR
Value: 5 or 6 dry, 3 to 5 moist
Chroma: 2 to 6, dry or moist
Texture: clay loam, sandy clay loam
Rock fragments: 40 to 70 percent total rock fragments; 15 to 55 percent gravel, 15 to 30 percent cobbles, 0 to 15 percent stones.
Reaction (pH): 6.1 to 7.8

2C horizon
Hue: 7.5YR or 10YR
Value: 4 to 7 dry, 4 or 5 moist
Chroma: 2 to 6, dry or moist
Texture: sandy loam, sandy clay loam, loam
Rock fragments: 50 to 80 percent total rock fragments; 10 to 55 percent gravel, 10 to 40 percent cobbles, 0 to 30 percent stones.
Reaction (pH): 6.1 to 7.8

COMPETING SERIES:
Elpeak (MT) - do not have a lithologic discontinuity
Elwood (UT) - are moderately deep to lithic contact
Ezbin (ID) - have an organic surface layer
Pholod (MT) - are moderately deep to lithic contact
Tahquats (ID) - have a moderately acidic reaction class in the particle size control section
Wander (CO) - formed in parent material derived from sandstone and shale

GEOGRAPHIC SETTING:
Landform - alluvial fans, pediments, fan remnants and mountain slopes
Elevation - 2,500 to 3,500 meters
Slopes - 5 to 65 percent
Parent material - alluvium, slope alluvium, and colluvium derived from andesite, rhyolite, breccia, or tuff
Mean annual air temperature - 0.0 to 4.4 degrees C.
Mean annual precipitation - 660 to 1,143 mm
Precipitation pattern - wettest months are July and August, while the driest months are May and June; however, the soils are still wet from snowmelt, and often still covered with snow through mid June
Frost-free period - 45 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Well drained; medium to very high runoff; moderately slow permeability.

USE AND VEGETATION: This soil is used for rangeland. Native vegetation is Thurber's fescue, Parry's danthonia, Arizona fescue, and big bluegrass. It is in the Subalpine Loam Range Site, RS 250.

DISTRIBUTION AND EXTENT: Western Colorado, southern Wyoming, Utah, New Mexico; LRR E, MLRA 13, 43B, 48A; moderate extent.

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

SERIES ESTABLISHED: Ouray Soil Survey Area, Hinsdale County, Colorado, 1998. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon: 0 to 25 cm (A horizon)
Argillic horizon: 25 to 76 cm (Bt horizon)
Particle-size control section: 25 to 75 cm (Bt horizon)

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


National Cooperative Soil Survey
U.S.A.