LOCATION RETAW NM+AZEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Cryaquolls
TYPICAL PEDON: Retaw mucky silt loam -- on a level rock basin at 8,950 feet elevation -- marsh. (Colors are for moist soil unless otherwise noted. When described, the soil was ponded with 20 inches of surface water, and was saturated below.
Oa--0 to 3 inches; black (10YR 2/1) muck, very dark gray (10YR 3/1) dry, massive; slightly hard, friable, slightly sticky and nonplastic; common fine and very fine roots; few small fragments of wood; moderately acid (pH 5.6); clear smooth boundary. (2 to 4 inches thick)
A1--3 to 8 inches; black (10YR 2/1) mucky silt loam, very dark gray (10YR 3/1) dry, weak very thick platy structure parting to moderate medium subangular blocky; hard, firm, slightly sticky and slightly plastic; few fine and common very fine roots; few very fine tubular pores; noneffervescent; moderately acid (pH 5.8); gradual smooth boundary. (3 to 8 inches thick)
A2--8 to 13 inches; black (10YR 2/1) mucky silty clay loam, very dark gray (10YR 3/1) dry, few fine prominent brown (7.5YR 4/4) redox concentrations; weak very thick platy structure; very hard, very firm, moderately sticky and moderately plastic; few fine and very fine roots; few very fine tubular pores; few laminae of fine sandy loam; noneffervescent; moderately acid (pH 5.8); clear smooth boundary. (5 to 11 inches thick)
Cg1--13 to 23 inches; dark gray (10YR 4/1) fine sandy loam, grayish brown (10YR 5/2) dry, few fine prominent brownish yellow (10YR 6/6) redox concentrations; massive; hard, firm, slightly sticky and slightly plastic; few fine and very fine roots; few fine and very fine tubular pores; few laminae of sandy clay loam; 5 percent gravel; noneffervescent; moderately acid (pH 5.6); clear smooth boundary. (5 to 14 inches thick)
Cg2--23 to 33 inches; gray (10YR 5/1) silty clay, light brownish gray (10YR 6/2) dry, common fine and medium prominent strong brown (7.5YR 5/8) redox concentrations; massive; very hard, very firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; few thin strata of sandy loam; large prominent black (10YR 2/1) organic stains along few angular seams; moderately acid (pH 5.6); abrupt smooth boundary. (6 to 19 inches thick)
C1--33 to 45 inches; grayish brown (2.5Y 5/2) sandy loam, light brownish gray (10YR 6/2) dry, few medium prominent strong brown (7.5YR 4/6) and few fine prominent yellowish red (5YR 4/6) redox concentrations; massive; hard, friable, slightly sticky and nonplastic; few very fine tubular pores; few laminae of sandy clay loam; moderately acid (pH 5.6); clear smooth boundary. (0 to 16 inches thick)
C2--45 to 70 inches; light olive brown (2.5Y 5/4) sandy loam, light gray (2.5Y 7/2) dry, few fine prominent dark yellowish brown (10YR 4/4) redox concentrations; massive; hard, friable, slightly sticky and nonplastic; few very fine tubular pores; few lenses of loamy sand; moderately acid (pH 5.6).
TYPE LOCATION: San Juan County, New Mexico; on the Navajo Indian Reservation about 8 miles southwest of Toadlena; 2,250 feet west and 1,300 feet south of the northeast corner of sec. 23, T.22N., R.20W.; Latitude 36 degrees 7 minutes 47 seconds N and Longitude 108 degrees 56 minutes 31 seconds W.
RANGE IN CHARACTERISTICS:
Soil moisture - Typically, the soil moisture control section (SMCS) is saturated throughout the year. The soil is ponded most of the year. Peraquic moisture regime.
Soil temperature - 40 to 42 degrees F. (Cryic) Mean annual and mean summer soil temperatures do not differ by more than 1 degree C. due to continual saturation with water.
Soil depth - greater than 60 inches to bedrock
Depth of ponded water - a few inches to 4.0 feet
Depth to base of Mollic epipedon - 10 to 16 inches
Depth to the base of the organic surface material - 2 to 4 inches
Silicate clay content, control section weighted average - 18 to 35 percent
Reaction - moderately acid to slightly acid
Oa horizon - Hue: 10YR or N (neutral).
Value: 3 or 4 dry, 2 or 3 moist.
Chroma: 0 or 1.
Organic carbon content: 12 to 13 percent.
A1 horizon - Hue: 10YR or N (neutral).
Value: 3 or 4 dry.
Chroma: 0 or 1.
Organic carbon content: 5 to 10 percent.
Clay content: 20 to 27 percent.
A2 horizon - Hue: 10YR or N (neutral).
Value: 3 or 4 dry, 2 or 3 moist.
Chroma: 0 or 1.
Organic carbon content: 5 to 10 percent.
Texture: mucky silty clay loam, mucky clay loam, or mucky silty clay. Clay content: 35 to 45 percent.
Redoximorphic features: none to few, fine to medium, prominent, brown or strong brown redox concentrations.
Cg horizons - Hue: 10YR through 5Y.
Value: 5 through 7 dry, 4 through 6 moist.
Chroma: 1 or 2.
Organic carbon content: less than 1 percent.
Texture: stratified fine sandy loam to silty clay.
Clay content: 18 to 45 percent.
Rock fragments: 0 to 5 percent gravel.
Redoximorphic features: few to common, fine to medium, distinct or prominent, dark yellowish brown, strong brown, or yellowish red redox concentrations; a reduced matrix or strong gleying is also present.
Lower C horizons - Hue: 10YR through 5Y.
Value: 6 or 7 dry, 5 or 6 moist.
Chroma: 2 through 4.
Organic carbon content: less than 0.5 percent.
Texture: stratified loamy sand to sandy clay loam.
Clay content: 10 to 25 percent.
Rock fragments: 0 to 5 percent gravel.
Redoximorphic features: few to common, fine to medium, prominent, dark yellowish brown, strong brown, or yellowish red redox concentrations; a reduced matrix may also be present.
Other features: some pedons have sandstone bedrock or flaggy layers between 40 and 60 inches.
COMPETING SERIES: These are the Blackwell (ID), Foolhen (MT), Furniss (ID), Haydenfork (UT) and Vensora (WY) series. Blackwell soils have a discontinuity of highly stratified materials at depths of 20 to 40 inches. Foolhen soils are slightly alkaline or moderately alkaline in the C horizon. Furniss soils have a discontinuity of sandy-skeletal material at a depth of 40 inches and deeper. Haydenfork soils display endoaquic soil moisture conditions at 0 to 10 inches in April to June. Vensora soils have skeletal textures within 40 inches.
GEOGRAPHIC SETTING: Retaw soils are on small rock basins of undulating high plateaus and mesas. The basins are rounded, closed depressions formed on sandstone bedrock and are 1 to about 50 acres in size. Most are covered with standing water year-round but smallest basins may dry out after successive years of drought. Runoff from melting winter snowpack and high-intensity summer thunderstorms fills the basins with water. Retaw soils formed in lacustrine sediments and alluvium derived from Tertiary sandstone. Slopes range from 0 to 1 percent. Elevation ranges from 8,500 to 9,200 feet. The mean annual precipitation is 20 to 22 inches with more than 50 percent falling as snow from winter storms. The mean annual air temperature is 40 to 42 degrees F. The average frost-free period is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Akhoni, Berland, Bikeyah, Captom and Klizhin soils. Akhoni soils are shallow to sandstone and occur on adjacent broad summits. Berland soils are very shallow to sandstone and occur on non-wooded knolls and benches. Bikeyah soils are somewhat poorly drained and occur on open, grassy toeslopes. Captom soils lack Mollic epipedons and occur on steep backslopes. Klizhin soils have thick Mollic epipedons and occur on footslopes below Captom soils.
DRAINAGE AND PERMEABILITY: Very poorly drained; negligible runoff; saturated hydraulic conductivity is low.
USE AND VEGETATION: Retaw soils are used for wildlife habitat and limited livestock grazing. Present vegetation is northern mannagrass, floatingleaf pondweed, mare's-tail, three-square bulrush, and needle spikerush.
DISTRIBUTION AND EXTENT: Retaw soils are of small extent on the Defiance Uplift-Chuska Mountains portion of the Colorado Plateau province in northwest New Mexico and northeast Arizona. MLRA is 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Shiprock Area, Parts of San Juan County, New Mexico and Apache County, Arizona; 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Epiaquic soil moisture conditions - The presence of surface ground water throughout the year perched over very slowly permeable layers above 80 inches.
Mollic epipedon - The zone from the top of the first mineral horizon to a depth of about 13 inches. (A1 and A2 horizons)
In August 2005, the taxonomic classification Fine-loamy, mixed, superactive, frigid Typic Cryaquolls was reviewed and updated resulting the current taxonomic classification.
Keys to Soil Taxonomy - Soils classified according to the Ninth Edition, 2003.
ADDITIONAL DATA: Organic carbon values are estimated