LOCATION TUNITCHA NMEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Haplustalfs
TYPICAL PEDON: Tunitcha very flaggy sandy loam -- on a convex backslope sloping 47 percent to the southeast at 9,000 feet elevation -- forest. (Colors are for dry soil unless otherwise noted.)
Oi-- 0 to 1 inch; forest litter of pine needles, twigs and cones; abrupt smooth boundary. (0 to 2 inches thick)
A-- 1 to 6 inches; dark grayish brown (10YR 4/2) very flaggy sandy loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky and nonplastic; common very fine roots; few very fine irregular and tubular pores; 20 percent pebbles and 30 percent flagstones; neutral (pH 6.8); clear smooth boundary. (2 to 8 inches thick)
BA-- 6 to 9 inches; brown (7.5YR 4/2) flaggy sandy loam, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and few medium roots; common very fine tubular pores; 10 percent pebbles and 20 percent flagstones; neutral (pH 6.8); clear smooth boundary. (0 to 8 inches thick)
2Bt1-- 9 to 26 inches; reddish brown (5YR 5/4) sandy clay loam; reddish brown (5YR 4/4) moist; moderate coarse parting to moderate fine subangular blocky structure; hard, friable, sticky and slightly plastic; common very fine and fine roots; few very fine tubular pores; many thin clay films on faces of peds and lining pores; slightly acid (pH 6.4); gradual smooth boundary. (7 to 20 inches thick)
2Bt2-- 26 to 39 inches; brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and few coarse roots; few very fine tubular pores; common thin clay films on faces of peds; neutral (pH 6.6); abrupt wavy boundary. (8 to 30 inches thick)
2C/Bt-- 39 to 51 inches; very pale brown (10YR 8/2)(C part) and light yellowish brown (10YR 6/4)(B part) gravelly sandy loam, pale brown (10YR 6/3) and dark yellowish brown (10YR 4/4) moist; massive; very hard, very firm, slightly sticky and nonplastic; common very fine and few coarse roots; few thin clay films on rock fragments; 25 percent soft sandstone fragments; neutral (pH 6.6); abrupt smooth boundary. (12 to 15 inches thick)
2C-- 51 to 58 inches; very pale brown (10YR 8/2) gravelly sandy loam, brown (10YR 5/3) moist; massive; slightly hard, very friable, slightly sticky and nonplastic; few very fine and medium roots; few very fine tubular pores; 15 percent soft sandstone fragments; neutral (pH 6.6); clear smooth boundary. (0 to 17 inches thick)
2Cr-- 58 inches; soft sandstone bedrock
TYPE LOCATION: San Juan County, New Mexico; on the Navajo Indian Reservation about 10 miles northwest of Toadlena; 1,650 feet east and 2,275 feet north of the southwest corner of section 12, T.24N., R.21W.; 36 degrees 19 minutes 40 seconds north latitude and 109 degrees 2 minutes 15 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture - Typically, the soil moisture control section (SMCS) is moist in all parts from January to May and intermittently moist in some part from June to December. The SMCS is moist in all parts greater than 40 percent of the time (cumulative), when the soil temperature at 20 inches is 41 degrees F or higher. Typic ustic moisture regime.
Soil temperature - 41 to 43 degrees F.
Soil depth - 40 to 60 inches to soft bedrock
Depth to base of argillic horizon - 30 to 42 inches
Reaction - slightly acid or neutral
A horizon
Hue: 7.5YR or 10YR.
Value: 3 to 5 dry, 2 or 3 moist.
Chroma: 2 or 3.
Organic carbon content: 1 to 2 percent.
Rock fragments: Total range is 35 to 60 percent. 10 to 20 percent pebbles. 5 to 10 percent channers, 0 to 5 percent are greater than 3 inches long. 20 to 30 percent flagstones, 0 to 5 percent are greater than 10 inches long.
BA horizon
Value: 4 to 6 dry, 3 or 4 moist.
Chroma: 2 to 4.
Organic carbon content: 0.6 to 2 percent.
Clay content: 10 to 18 percent.
Rock fragments: Total range is 15 to 35 percent. 5 to 10 percent pebbles. 0 to 10 percent cobbles. 10 to 25 percent flagstones.
2Bt horizons
Hue: 5YR or 7.5YR.
Value: 4 to 7 dry, 3 to 5 moist.
Chroma: 3 to 6.
Organic carbon content: less than 0.6 percent.
Clay content: 20 to 27 percent.
Rock fragments: Total range 0 to 15 percent. 0 to 5 percent pebbles. 0 to 5 percent channers. 0 to 5 percent flagstones.
Other features: 0 to 15 percent soft sandstone fragments.
2C/Bt horizon
Hue: 7.5YR or 10YR.
Value: 5 or 6 dry, 4 to 6 moist.
Chroma: 2 to 6.
Organic carbon content: less than 0.6 percent.
Texture: sandy loam or fine sandy loam.
Clay content: 10 to 18 percent.
Other features: 0 to 25 percent soft sandstone fragments.
2C horizon
Hue: 7.5YR or 10YR
Value: 6 to 8 dry, 5 or 6 moist.
Chroma: 2 to 4.
Organic carbon content: less than 0.6 percent.
Texture: sandy loam or fine sandy loam.
Clay content: 10 to 18 percent.
Other features: 0 to 30 percent soft sandstone fragments.
COMPETING SERIES: These are the
Alderon (WY),
Allens Park (CO),
Bayerton (WY),
Belltower (MT),
Elbeth (CO),
Elbuck (NM),
Elmark (MT),
Haugan (MT),
Heflin (CO),
Hoyt (MT),
Jemco (CO),
Jemez (NM),
Kunz (UT),
Kwiavu (CO),
Littlepine (CO),
Losindios (NM),
Lumpgulch (MT),
Northrim (CO),
Plome (CO),
Shoemaker (NM) and
Sweetweed (MT ), soils.
Alderson: are moderately deep over a paralithic contact.
Allens Park, Bayerton, Jemco, Jemez, Lumpgulch, and Shoemaker: has a lithic contact between 20 and 40 inches.
Belltower: has free carbonate accumulation in the control section.
Elbeth, Elbuck, Haugon, Hoyt, Kunz, Kwaivu, Littlepine, Losindios, Northrim, Plome, and Sweetweed: does not have a lithic or paralithic contact within 60 inches of the surface
Elmark: have lithic contacts between 40 and 60 inches
Heflin: was not adequately competed in 2004 when it was reclassified from mesic to frigid and from Udic to Typic.
GEOGRAPHIC SETTING: Tunitcha soils are on backslopes of high plateaus, mesas and structural benches. They formed in colluvium and residuum derived from Tertiary sandstone. Slopes range from 45 to 60 percent. Elevation ranges from 8,500 to 9,200 feet. The mean annual precipitation is 20 to 24 inches with more than 50 percent falling as snow from winter storms. The mean annual temperature is 39 to 41 degrees F. The average frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Akhoni, Bangston, and Klizhin soils. Akhoni soils are shallow to sandstone. Bangston soils lack argillic horizons, are sandy and occur on colder, north facing backslopes. Klizhin soils are coarse-loamy and occur on footslopes.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderate permeability
USE AND VEGETATION: Tunitcha soils are used for timber production and limited livestock grazing. Present vegetation is ponderosa pine and Douglas fir with an understory of Gambel oak, nodding bromegrass, bottlebrush squirreltail, Oregon-grape, earth sedge, and silvery lupine.
DISTRIBUTION AND EXTENT: Tunitcha soils are of small extent on the Defiance Upwarp-Chuska Mountains portion of the Colorado Plateau province in northwest New Mexico and northeast Arizona. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: San Juan County (Shiprock Area Soil Survey), New Mexico, 1993. Tunitcha is a place name.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to a depth of about 8 inches. (A and BA horizons)
Mollic feature - darker colors in A and BA horizons that are too thin for a mollic epipedon.
Argillic horizon - The zone from 8 to 38 inches. (2Bt1 and 2Bt2 horizons)
Paralithic contact - The presence of soft sandstone bedrock at 57 inches.
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.
ADDITIONAL DATA: Organic carbon values are estimated.
-Annual Pattern of Soil-Water States- ---------------------------------------------------------- -Depth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec (in) 0-5 f f f m m d d d d m m f 5-8 f f m m m d d m d m m f 8-25 m m m m m m d d d d m m 25-38 d d d d m m d d d d d m 38-50 d d d d d m m d d d d d 50-57 d d d d d d m d d d d d ------------------------------------------------------------ f: frozen more than half of the month w: wet more than half of the month m: moist more than half of the month d: dry more than half of the month
Information gathered from: Estimates and field notes