LOCATION MESITA COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Leptic Torrertic Natrustolls
TYPICAL PEDON: Mesita silty clay loam, 0 to 1 percent slopes in rangeland at an elevation of 7578 feet. (colors are for dry soil unless otherwise noted)
A--0 to 8 centimeters; grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; 32 percent clay; moderate medium platy structure; friable, very hard, moderately sticky, moderately plastic; common very fine, fine and medium roots throughout; common very fine vesicular pores; irregular salt masses at top of horizon; slightly effervescent (2 percent calcium carbonate equivalent); 1 percent gypsum content; very strongly alkaline (pH 9.2); clear smooth boundary.
Btnz1--8 to 25 centimeters; dark grayish brown (10YR 4/2) silty clay, very dark brown (10YR 2/2) moist; 42 percent clay; moderate coarse prismatic structure, and strong medium granular structure; firm, very hard, very sticky, very plastic; common very fine, fine and medium roots throughout; common very fine irregular pores; few distinct clay films throughout; salt masses throughout; slightly effervescent (2 percent calcium carbonate equivalent); 1 percent gypsum content; very strongly alkaline (pH 9.4); clear wavy boundary.
Btnz2--25 to 53 centimeters; grayish brown (10YR 5/2) clay, very dark grayish brown (10YR 3/2) moist; 45 percent clay; strong medium prismatic structure, and strong fine angular blocky structure; firm, extremely hard, very sticky, very plastic; common very fine, fine and medium roots throughout; common very fine irregular pores; few distinct clay films throughout; salt masses throughout; slightly effervescent (2 percent calcium carbonate equivalent); 2 percent gypsum content; very strongly alkaline (pH 9.4); clear wavy boundary.
Btknyz--53 to 97 centimeters; grayish brown (10YR 5/2) clay, very dark grayish brown (10YR 3/2) moist; 40 percent clay; strong medium angular blocky structure; firm, extremely hard, very sticky, very plastic; common very fine, fine and medium roots throughout; common very fine irregular pores; few distinct clay films throughout; salt masses throughout and many medium gypsum masses infused into matrix adjacent to pores; strongly effervescent (10 percent calcium carbonate equivalent); 4 percent gypsum content; very strongly alkaline (pH 9.4); clear wavy boundary.
2By--97 to 117 centimeters; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; 20 percent clay; weak fine subangular blocky structure; very friable, slightly hard, slightly sticky, nonplastic; common very fine roots throughout; common very fine irregular pores; 5 percent fine faint strong brown (7.5YR 5/6) masses of oxidized iron; few fine gypsum masses in matrix; 5 percent gravel; slightly effervescent (2 percent calcium carbonate equivalent); 1 percent gypsum content; strongly alkaline (pH 9.0); clear wavy boundary.
2C--117 to 140 centimeters; brown (10YR 5/3) loamy sand, dark brown (10YR 3/3) moist; 5 percent clay; weak fine subangular blocky structure; loose, loose, nonsticky, nonplastic; common very fine roots throughout; common very fine irregular pores; 5 percent fine faint strong brown (7.5YR 5/6) masses of oxidized iron; 5 percent gravel; noneffervescent; strongly alkaline (pH 8.8); clear wavy boundary.
3C--140 to 203 centimeters; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; 40 percent clay; moderate fine subangular blocky structure, and moderate medium subangular blocky structure; firm, very hard, very sticky, very plastic; common very fine roots throughout; common very fine irregular pores; 5 percent fine distinct strong brown (7.5YR 5/6) masses of oxidized iron; 2 percent gravel; noneffervescent; strongly alkaline (pH 8.6).
TYPE LOCATION: Costilla County, CO; Lasauses NW USGS topographic quadrangle, NAD83; 37 degrees 20 minutes 16.63 seconds north latitude and 105 degrees 41 minutes 13.14 seconds west longitude; UTM 439,146 meters E, 4132,585 meters N, zone 13.
RANGE IN CHARACTERISTICS:
Soil moisture:
Soil moisture regime subclass: ustic
Soil moisture regime class: aridic (torric)
Mean annual soil temperature: 41 to 46 degrees F 41 to 46 degrees F (5 to 7.8 centimeters).
Mean summer soil temperature: 63 to 66 to degrees F (17.2 to 18.9 centimeters)
Depth to salt accumulations: 0 inches (0 centimeters)
Depth to natric horizon: 2 to 6 inches (5 to 15 centimeters)
Depth to gypsum accumulations: 16 to 26 inches (41 to 66 centimeters)
Depth to secondary carbonates: 0 to 26 inches (0 to 66 centimeters)
centimeters) to secondary carbonates Thickness of mollic epipedon: 10 or more inches (25 or more centimeters)
Thickness of the natric horizon: 25 to 55 inches (64 to 140 centimeters)
Seasonal high water table: April, May and June
Depth to top: 42 to 72 inches (107 to 183 centimeters)
Particle-size control section (weighted average):
Clay content: 35 to 50 percent
Sand content: 15 to 35 percent
Rock fragments: 0 to 15 percent subrounded gravel
A horizon(s)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: silty clay loam
Clay content: 27 to 40 percent
Carbonate clay content: 2 to 8 percent
Sand content: 3 to 25 percent
Silt content: 40 to 70 percent
Fragment content, total: 0 to 5 percent
Fragment size and content: 0 to 5 percent indurated gravel
Calcium carbonate equivalent: 0 to 5 percent
Gypsum content: 0 to 5 percent
Electrical conductivity: 4 to 30 mmhos/cm
Sodium adsorption ratio: 13 to 100
Reaction: pH 8.5 to 9.6
Organic matter content: 1.0 to 2.0 percent
Btnz horizon(s)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 2 to 4 moist
Chroma: 2 or 3
Texture: clay, silty clay, silty clay loam, clay loam
Clay content: 27 to 50 percent
Carbonate clay content: 2 to 10 percent
Sand content: 10 to 35 percent
Silt content: 25 to 50 percent
Fragment content, total: 0 to 5 percent
Fragment size and content: 0 to 5 percent indurated gravel
Calcium carbonate equivalent: 1 to 5 percent
Gypsum content: 0 to 5 percent
Electrical conductivity: 4 to 30 mmhos/cm
Sodium adsorption ratio: 13 to 100
Reaction: pH 8.5 to 9.6
Organic matter content: 0.5 to 1.5 percent
Btknyz horizon(s)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 2 to 4 moist
Chroma: 2 or 3
Texture: clay, clay loam, silty clay
Clay content: 27 to 50 percent
Carbonate clay content: 4 to 15 percent
Sand content: 10 to 35 percent
Silt content: 25 to 50 percent
Fragment content, total: 0 to 5 percent
Fragment size and content: 0 to 5 percent indurated gravel
Calcium carbonate equivalent: 1 to 15 percent
Gypsum content: 1 to 5 percent
Electrical conductivity: 4 to 30 mmhos/cm
Sodium adsorption ratio: 13 to 100
Reaction: pH 8.5 to 9.6
Organic matter content: 0.0 to 0.5 percent
2By horizon(s)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 2 to 4 moist
Chroma: 2 or 3
Texture: sandy clay loam, sandy loam
Clay content: 12 to 35 percent
Carbonate clay content: 2 to 8 percent
Sand content: 25 to 70 percent
Silt content: 20 to 45 percent
Fragment content, total: 0 to 15 percent
Fragment size and content: 0 to 15 percent indurated gravel
Calcium carbonate equivalent: 1 to 5 percent
Gypsum content: 0 to 5 percent
Electrical conductivity: 2 to 16 mmhos/cm
Sodium adsorption ratio: 2 to 20
Reaction: pH 8.5 to 9.6
Organic matter content: 0.0 to 0.5 percent
2C horizon(s)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 2 to 4 moist
Chroma: 2 or 3
Texture: loamy sand
Clay content: 5 to 15 percent
Carbonate clay content: 0 to 2 percent
Sand content: 70 to 85 percent
Silt content: 10 to 20 percent
Fragment content, total: 0 to 15 percent
Fragment size and content: 0 to 15 percent indurated gravel
Gypsum content: 0 to 3 percent
Electrical conductivity: 2 to 16 mmhos/cm
Sodium adsorption ratio: 0 to 20
Reaction: pH 8.5 to 9.6
Organic matter content: 0.0 to 0.5 percent
3C horizon(s)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 or 3
Texture: clay
Clay content: 27 to 45 percent
Carbonate clay content: 0 to 2 percent
Sand content: 20 to 50 percent
Silt content: 20 to 45 percent
Fragment content, total: 0 to 15 percent
Fragment size and content: 0 to 15 percent indurated gravel
Gypsum content: 0 to 1 percent
Electrical conductivity: 2 to 16 mmhos/cm
Sodium adsorption ratio: 0 to 20
Reaction: pH 8.5 to 9.6
Organic matter content: 0.0 to 0.5 percent
COMPETING SERIES: This soil is the
Gerda series.
Gerda soils are well drained
GEOGRAPHIC SETTING:
Parent material: clayey lacustrine deposits derived from mixed sources
Landform: Flood plain
Slopes: 0 to 1 percent
Elevation: 7,500 to 8,500 feet (2,286 to 2,591 meters)
Mean annual air temperature: 39 to 43 degrees F (4.0 to 6.0 degrees C.)
Mean annual precipitation: 8 to 12 inches (203 to 305 millimeters)
Precipitation pattern: Precipitation peak in July and August occurring as intense summer thunderstorms.
Frost-free period: 85 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Vastine and
Gerrard soils are fine-loamy over sandy-skeletal.
Eastdale soils are poorly drained.
DRAINAGE AND PERMEABILITY: moderately well drained, low runoff, very slow permeability, occasionally flooded for brief periods during the months of April, May, and June.
USE AND VEGETATION: The soils are used principally as native pastureland. Principal native vegetation includes greasewood, inland salt grass rabbitbrush,and blue grama.
DISTRIBUTION AND EXTENT: San Luis Valley Area of south-central Colorado. LRR E, MLRA 51. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Costilla County, CO, Costilla County Soil Survey Area, CO, 2009. The name Mesita is coined.
Remarks:
Diagnostic horizons and features:
Mollic epipedon: 25 or more centimeters (10 or more inches)
Natric horizon: 8 to 97 centimeters (3 to 38 inches)
Depth to gypsum accumulations: 53 centimenters
Taxonomic Version: Tenth Edition, 2006