LOCATION EVPARK NM+AZ UT
The Evpark series consists of moderately deep, well drained, moderately slowly permeable soils that formed in eolian and slope alluvium derived from sandstone and shale. Evpark soils are on mesas, dipslopes of cuestas, structural benches and ridges. Slopes range from 1 to 8 percent. Mean annual precipitation is about 16 inches, and the mean annual air temperature is about 48 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Haplustalfs
TYPICAL PEDON: Evpark fine sandy loam--in a chained area on southwest facing slope of 4 percent at an elevation of 7300 feet. (Colors are for dry soils unless otherwise noted.)
A--0 to 3 inches; brown (7.5YR 5/4) fine sandy loam, dark brown (7.5YR 3/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; few fine tubular pores; neutral (pH 7.2); abrupt smooth boundary. (2 to 3 inches thick)
Bt1--3 to 16 inches; brown (7.5YR 4/4) clay loam, dark brown (7.5YR 3/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; few fine tubular pores; common distinct clay films bridging sand grains; neutral (pH 7.2); clear smooth boundary.
Bt2--16 to 20 inches; brown (7.5YR 4/4) clay loam, strong brown (7.5YR 4/6) moist; strong medium prismatic structure; hard, firm, sticky and slightly plastic; common very fine and few fine roots; few fine tubular pores; many prominent clay films coating faces of peds; neutral (pH 7.2); clear smooth boundary.
Bt3--20 to 29 inches; strong brown (7.5YR 4/6) sandy clay loam, strong brown (7.5YR 4/6) moist; strong medium prismatic structure; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; few very fine tubular pores; many prominent clay films coating faces of peds and bridging sand grains; slightly alkaline (pH 7.4); abrupt smooth boundary. (The combined thickness of the Bt horizons is 16 to 24 inches.)
Btk--29 to 35 inches; strong brown (7.5YR 4/6) sandy clay loam, brown (7.5YR 5/4) moist; weak medium prismatic structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine tubular pores; common prominent clay films coating faces of peds and bridging sand grains; strongly effervescent; common fine soft seams and soft filaments of calcium carbonate 5 percent; slightly alkaline (pH 7.6); abrupt smooth boundary (0 to 6 inches thick).
2R--35 inches; sandstone
TYPE LOCATION: Cibola County, New Mexico; Plumasano Basin Quadrangle; about 1.5 miles northeast of Plumasano Basin on the Zuni Indian Reservation; 108 degrees 47 minutes 13 seconds west longitude, 34 degrees 56 minutes 22 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: The SMCS is usually moist, in all parts, for less than 90 cumulative days from April through October. It is usually dry, in some part, for more than 120 cumulative days during the same period. It is continuously moist in some part November through April, but not moist in all parts for 45 consecutive days from January through April. The period of maximum precipitation is July through October. The soil is driest during May and June. Aridic ustic soil moisture regime.
Soil Temperature: 47 to 53 degrees F.
Depth to lithic contact: 20 to 40 inches to sandstone
Particle-size control section: 20 to 35 percent clay and greater than 35 percent sand
Hue: 7.5YR, 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4 moist
When this horizon has mollic colors it is too thin to qualify for a mollic epipedon
Texture: fine sandy loam, loam
Rock fragments: 0 to 10 percent sandstone gravel
Hue: 5YR, 7.5YR
Value: 4 or 5 dry, 3 to 5 moist
Chroma: 3 to 4, dry or moist
Texture: loam, sandy clay loam, very fine sandy loam, clay loam
Rock fragments: 0 to 5 percent sandstone gravel, individual horizons may range up to 25 percent
Hue: 5YR, 7.5YR
Value: 4 to 6 dry, 4 or 5 moist
Chroma: 4 to 6, dry or moist
Percent calcium carbonate equivalent: less than 10 percent
Bk horizons (when present)
Textures: sandy clay loam, fine sandy loam
Calcium carbonate equivalent: less then 10 percent
COMPETING SERIES: These are the
Flugle (NM), Fort Collins (CO),
Toluca (MT), and
Wagonhound (WY) series.
Flugle, Fort Collins,
Stoneham soils are very deep.
Wagonhound soils are moist during
May and June.
Celavar soils have paralithic contacts.
Nyjack soils are noneffervescent throughout.
Carri soils do not have accumulations of secondary calcium carbonate.
GEOGRAPHIC SETTING: The Evpark soils formed in eolian and slope alluvium derived from sandstone and shale and are on summits of mesas, dipslopes of cuestas, structural benches and ridges. Slopes are 1 to 8 percent. Elevations range from 5,800 to 8,000 feet. The mean annual air temperature is 45 to 51 degrees F. The mean annual precipitation is 13 to 18 inches. The frost-free period is 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Highdye soils on summits of mesas and dipslopes of cuestas.
Vessilla soils are on escarpments of mesas and cuestas. Bryway soils are moderately deep to shale. Highdye, Toldohn, and Vessilla soils are very shallow and shallow to sandstone and shale.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, moderately slowly permeability.
USE AND VEGETATION: This series is used for wood products and livestock grazing. The present vegetation is pinyon and juniper with an understory of big sagebrush, mountain mahogany, antelope bitterbrush, blue grama, muttongrass, prairie junegrass, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: West central New Mexico and northeast Arizona. MLRA 35, LRR-D. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: McKinley County Area, New Mexico; McKinley County and Parts of Cibola and San Juan Counties, 2001.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 3 inches (A horizon)
Argillic horizon - the zone from 3 to 35 inches (Bt1, Bt2, Bt3, Btk horizons)
Lithic contact the boundary at 35 inches-- sandstone bedrock (2R horizon)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, 11th Edition, 2010.
Updates and revisions for the correlation of Ft. Defiance Area (AZ715), February 2008, DWD
Update and revisions for the correlation of Chinle Area (AZ713), August 2011, LJG2
National Cooperative Soil Survey