LOCATION CHIMROCK COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Argigypsids
TYPICAL PEDON: Chimrock very fine sandy loam, on a southwest facing, 3 percent slope in rangeland at an elevation of 5,290 feet. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; light yellowish brown (10YR 6/4) very fine sandy loam, brown (10YR 5/3) moist; moderate very thick platy structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic; common very fine roots throughout; common very fine vesicular pores; strongly effervescent; 1 percent gravel; moderately alkaline (pH 8.1); abrupt smooth boundary. (2 to 6 inches thick)
AB--3 to 15 inches; pale brown (10YR 6/3) loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; moderately hard, very friable, nonsticky and nonplastic; few very fine roots throughout; few very fine dendritic tubular pores; very few distinct clay films on faces of peds and in pores; 10 percent calcium carbonate; 1 percent gravel; violently effervescent; strongly alkaline (pH 8.5); gradual smooth boundary.
Bt--15 to 32 inches; pale brown (10YR 6/3) loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; very hard, firm, slightly sticky and slightly plastic; common very fine roots throughout; few very fine dendritic tubular pores; few distinct clay films on faces of peds and in pores; common fine carbonate threads throughout; 11 percent calcium carbonate; 1 percent gypsum; 1 percent gravel; violently effervescent; moderately alkaline (pH 7.9); abrupt wavy boundary. (10 to 24 inches thick)
By--32 to 46 inches; pale brown (10YR 6/3) silt loam, olive brown (2.5Y 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few fine gypsum threads throughout; gypsum pendants beneath coarse fragments; 9 percent calcium carbonate; 5 percent gypsum; 5 percent gravel; slightly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (6 to 20 inches thick)
C--46 to 66 inches; pale brown (10YR 6/3) loam, olive brown (2.5Y 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few fine gypsum threads throughout; 9 percent calcium carbonate; 2 percent gypsum; 3 percent gravel; slightly effervescent; moderately alkaline (pH 8.3).
TYPE LOCATION: Montezuma County, Colorado; about 1/3 mile south of Chimney Rock; Tanner Mesa, Colorado USGS quad; lat. 37 degrees 03 minutes 54 seconds N. and long. 108 degrees 43 minutes 00 seconds W., NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: Typic aridic
Mean annual soil temperature: 54 to 58 degrees F
Depth to argillic horizon: 5 to 32 inches
Depth to secondary calcium carbonate: 5 to 20 inches
Depth to gypsum accumulations: 15 to 35 inches
Depth to gypsic horizon: 18 to 35 inches
Particle-size control section (weighted average):
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent sandstone gravel
A horizon:
Hue: 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: loam and very fine sandy loam
Clay content: 10 to 27 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 5 to 15 percent
EC (mmhos/cm): 0 to 2
Gypsum: 0 to 2 percent
SAR: 0 to 13
Reaction: moderately alkaline
Bt horizon (or Btn if present):
Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: loam, clay loam, silt loam, silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 5 to 15 percent
EC (mmhos/cm): 0 to 8
Gypsum: 0 to 3 percent
SAR: 0 to 30
Reaction: moderately alkaline
By horizon:
Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: sandy loam, loam, silt loam, clay loam, sandy clay loam, or silty clay loam
Clay content: 5 to 35 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 1 to 30 percent
EC (mmhos/cm): 4 to 16
Gypsum: 1 to 10 percent
SAR: 0 to 30
Reaction: moderately alkaline
COMPETING SERIES: These are the
Fruita (CO),
Fruitvale (CO) and
Yogovuci (CO) series. Fruita soils have more than 15 percent by weight gypsum in the gypsic horizon
Fruitvale soils have clayey substrata. Yogovuci soils are derived from eolian deposits and igneous materials and have lithologic discontinuities with stratified sandy and sandy-skeletal substratum.
GEOGRAPHIC SETTING:
Parent material: slope alluvium derived from shale and sandstone
Landform: broad alluvial fans
Slopes: 0 to 3 percent
Elevation: 4,800 to 5,700 feet
Mean annual temperature: 52 to 56 degrees F
Mean annual precipitation: 7 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 Persayo and Ravola series, and Torriorthents. The Persayo soils are shallow to shale and are on hills. The Ravola soils are fine-silty and are in drainageways. The Torriorthents soils lack development and are on sideslopes of mesas.
DRAINAGE AND PERMEABILITY: Well drained, negligible to low runoff, moderately slow permeability.
USE AND VEGETATION: Rangeland. The dominant vegetation in the potential plant community is galleta, winterfat, fourwing saltbush, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Southwest Colorado; MLRA 35; 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 59 inches.
Particle-size control section: The zone from 15 to 32 inches. (Bt horizon)
Ochric epipedon: The zone from 0 to 15 inches. (A, AB horizons)
Argillic horizon: The zone from 15 to 32 inches. (Bt horizons)
Gypsic horizon: The zone from 32 to 46 inches. (By1 horizon)
ADDITIONAL DATA: National Soil Survey Laboratory sample S99-CO-083-09.
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003