LOCATION PESCADO NMInactive Series
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic Lithic Haplustalfs
TYPICAL PEDON: Pescado fine sandy loam--on a south-facing slope of 2 percent in rangeland at an elevation of 6,830 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 subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; few fine irregular pores; neutral (pH 6.8); clear smooth boundary. (2 to 3 inches thick)
Bt1--3 to 10 inches; reddish brown (5YR 4/4) sandy clay loam, dark reddish brown (5YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few fine irregular pores; many prominent clay films bridging sand grains and coating faces of peds; few (less than 1 percent) basalt pebbles; neutral (pH 6.8); clear smooth boundary. (4 to 9 inches thick)
Bt2--10 to 16 inches; reddish brown (5YR 4/4) clay loam, dark reddish brown (5YR 3/4) moist; moderate fine and medium subangular blocky structure; hard, firm, sticky and plastic; few very fine and fine roots; few fine irregular pores; many prominent clay films bridging sand grains and coating faces of peds; few (less than 1 percent) basalt pebbles; violently effervescent 1 inch layer above the lithic contact with basalt; slightly alkaline (pH 7.4); abrupt smooth boundary. (0 to 15 inches thick)
2R--16 inches; basalt
TYPE LOCATION: McKinley County, New Mexico; Pescado Quadrangle; about 200 feet south of Pescado Reservoir on the Zuni Indian Reservation; 108 degrees 33 minutes 20 seconds west longitude, 35 degrees 6 minutes 10 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 days cumulative days during the same period. It is continuously moist in some part November through April, but not moist 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 moisture regime.
Soil Temperature: 50 to 55 degrees F
Soil Depth: 7 to 20 inches to basalt
Particle-size control section: 20 to 35 percent clay, greater than 35 percent sand
A horizon
Value: 3 or 4 moist
Rock fragments: 0 to 10 percent basalt pebbles
Bt horizons
Hue: 7.5YR or 5YR
Rock fragments: 0 to 5 percent pebbles
Textures: sandy clay loam and clay loam
Reaction: neutral and slightly alkaline
COMPETING SERIES: These are the
Arabrab (CO),
Atarque (NM),
Simitarq (NM), Urraca (NM),
Valena (AZ) and
Verite (AZ) series.
Arabrab soils have 5 to 30 percent rock fragments in the lower Bt horizon.
Arabrab, Atarque, and Simitarq soils formed on sandstone.
Simitarq soils have more than 35 percent clay in the lower argillic horizons.
Valena soils formed from granite, particle size control section contain more than 50 percent sand and more than 5 percent 2 to 5 mm gravel size fragments.
Urraca and Verite soils have typic ustic soil moisture regimes.
GEOGRAPHIC SETTING: The Pescado soils formed in eolian materials derived from sandstone and are on convex slopes on basalt flows on valley floors. The eolian materials and the underlying basalt are deposits from the Quaternary period. Slopes are 1 to 8 percent. Elevations range from 6400 to 7000 feet. The mean annual temperature is 48 to 53 degrees F., and the mean annual precipitation is 13 to 16 inches. The frost free period is 115 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Toldohn and Vessilla soils on escarpments of mesas and cuestas; the Ramah soils on lava flows and fan terraces; the Hosta soils on fan terraces; and the Concho soils on stream terraces. The Toldohn soils are shallow to a paralithic contact to shale; the Vessilla soils have less than 18 percent clay in the particle-size control section and are shallow to sandstone; and the Ramah, Hosta, and Concho soils are fine textured and very deep.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, and moderately slow permeability.
USE AND VEGETATION: This series is used primarily for rangeland with minor areas used for urban development and subsistent crops. Present vegetation is big sagebrush, broom snakeweed, blue grama, bottlebrush squirreltail, threeawns, and widely scattered pinyon and oneseed juniper.
DISTRIBUTION AND EXTENT: West central New Mexico. MLRA 35, LRR-D. This series is of small 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 16 inches. (Bt1 and Bt2 horizons)
Lithic contact: 16 inches--basalt. (2R horizon)
Classified according to Soil Taxonomy Second Edition, 1999.