LOCATION SAN JON            NM+TX
Established Series
Rev. RAH-RJA-ACT-CLN
09/2007

SAN JON SERIES


The San Jon series consists of moderately deep, well drained, moderately slowly permeable soils that formed in alluvium and eolian material from sandstone and shale mainly of the Santa Rosa and Chinle Formations of Triassic age. These soils are on pediments below escarpments, undulating hills and structural benches. Slope ranges from 0 to 25 percent. Mean annual precipitation is about 356 mm (14 in) and mean annual temperature is about 17 degrees C (62 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Ustic Haplocalcids

TYPICAL PEDON: San Jon loam - rangeland. (Colors are for dry soil unless otherwise stated.)

A--0 to 10 cm (0 to 4 in); reddish brown (5YR 5/3) loam, reddish brown (5YR 4/3) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and plastic; common very fine roots; many very fine and fine pores; common clusters of fine insect casts; 10 percent coarse fragments of indurated calcium carbonate and lime-coated sandstone pebbles; slightly effervescent; moderately alkaline; clear smooth boundary. (8 to 15 cm thick)

Bw--10 to 20 cm (4 to 8 in); reddish brown (5YR 5/3) loam, reddish brown (5YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, plastic; many very fine roots; many very fine and fine pores; common clusters of fine insect casts; 10 percent coarse fragments of indurated calcium carbonate and calcium carbonate coated sandstone pebbles; strongly effervescent; moderately alkaline; clear smooth boundary. (10 to 43 cm thick)

Bk1--20 to 30 cm (8 to 12 in); reddish brown (5YR 5/4) gravelly clay loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and plastic; common very fine roots; common very fine pores; few clusters of fine insect casts; 30 percent coarse fragments mostly indurated calcium carbonate; violently effervescent; few fine calcium carbonate masses; strongly alkaline; clear wavy boundary.

Bk2--30 to 43 cm (12 to 17 in); light reddish brown (5YR 6/4) clay loam, reddish brown (5YR 5/4) moist; weak fine subangular blocky structure and few scattered areas of relict angular soft shale fragments; few fine roots; common very fine pores; few clusters of fine insect casts; 5 percent indurated calcium carbonate fragments and lime-coated sandstone pebbles; violently effervescent; common very fine calcium carbonate concretions and fine calcium carbonate masses; strongly alkaline; clear wavy boundary.

Bk3--43 to 64 cm (17 to 25 in); red (2.5YR 5/6) silty clay loam, red (2.5YR 4/6) moist; massive; very hard, firm, sticky and plastic; few very fine roots; violently effervescent, common fine calcium carbonate accumulations; moderately alkaline; diffuse irregular boundary. (Combined thickness of Bk horizon is 25 to 64 cm)

Cr--64 to 122 cm (25 to 48 in); fragmental shale, overlapping angular platy shale rock structure; very hard, firm, wets with difficulty; weakly calcareous along fracture planes in upper part, noncalcareous in lower part; moderately alkaline.

TYPE LOCATION: Quay County, New Mexico; from the intersection of I-40 and NM State Highway 93; 13.3 km (8.3 miles) south on NM State Highway 93 (0.1 mile south of bridge); 30.5 meters (100 feet) west in rangeland. Section 34, T. 10 N., R. 36 E.; Latitude 35 degrees, 3 minutes, 9 seconds N; Longitude: 103 degrees, 6 minutes, 11 seconds W; Rock Camp, New Mexico USGS quad; NAD 83.

RANGE IN CHARACTERISTICS:
Soil Moisture: An aridic moisture regime bordering on ustic. The soil moisture control section is dry in all parts for 205 but less than 270 days cumulative, in normal years. October and May are the driest months. These soils are intermittently moist from June through September.
Soil temperature: 15 to 21 degrees C (59 to 70 degrees F).
Depth to paralithic contact: 50 to 100 cm (20 to 40 in).
Rock fragments: average less than 15 percent pebbles, but ranges to 40 percent pebbles in any individual horizon.

A horizon:
Hue: 2.5YR, 5YR, 7.5YR
Value: 5 to 8, 4 to 7 moist
Chroma: 3 or 4
Texture: sandy loam, fine sandy loam, loam, gravelly loam or clay loam
Reaction: slightly alkaline to strongly alkaline.

Bk, or Bw horizon where present:
Hue: 2.5YR, 5YR, 7.5YR
Value: 4 to 8, 3 to 7 moist
Chroma: 2 to 6
Texture (fine earth fraction): loam, gravelly loam, sandy clay loam, clay loam or silty clay loam
Calcium carbonate equivalent: 15 to 40 percent
Reaction: slightly alkaline to strongly alkaline.

Cr horizon:
Hue: 2.5YR to 7.5YR
Value: 4 to 6, 3 to 5 moist
Chroma: 4 to 6
Fragmental weakly cemented shale or sandstone, overlapping angular, platy fragments of shale rock.

COMPETING SERIES: These are the Chispa (TX), Elfrida (AZ), Kahn (AZ), Laborcita (NM), Pandale (TX), Ratliff (TX), Salado (NM), and Tuzigoot (AZ) series. All these soils have more than 100 cm deep sola. In addition, Kahn and Tuzigoot soils are intermitently moist during the period July to September and December to February.

GEOGRAPHIC SETTING:
Parent material: alluvium and eolian material from sandstone and shale mainly of the Santa Rosa and Chinle Formations of Triassic age.
Landform: pediments below escarpments and undulating hills and structural benches.
Slopes: 0 to 25 percent
Mean annual temperature: 15 to 21 degrees C (57 to 68 degrees F).
Mean annual precipitation: 305 to 381 mm (12 to 15 in)
Precipitation pattern: more than one-half occurs during the summer months as heavy thunderstorms.
Frost-free period: 180 to 200 days
Elevation: 1,280 to 1,620 meters (4,200 to 5,300 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alama, Ima, Montoya, and Tucumcari soils.
Alama soils: do not have a calcic horizon and have deep sola.
Ima soils: are deep, do not have a calcic horizon and contain less than 18 percent clay in the particle-size control section.
Montoya soils: are deep, do not have a calcic horizon and contain more than 35 percent clay in the control section.
Tucumcari soils: are deep and have a fine textured argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately slow. Runoff is negligible on slopes less than 1 percent, very low on 1 to 3 percent slopes, low on 3 to 5 percent slopes, medium on 5 to 20 percent slopes, and high on 20 to 25 percent slopes.

USE AND VEGETATION: Principal use is for livestock grazing and wildlife habitat. Present native vegetation is mixed mid grasses dominantly gramas and threeawn with some tobosa and a few scattered yuccas. The ecological site is Loamy (R070XB052NM) or Sandy Loam (R070XB054NM).

DISTRIBUTION AND EXTENT: Upper Pecos River Valley (MLRA 70B in LRR G) of eastern New Mexico and western Texas. The series is of large extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Quay County (Tucumcari Area), New Mexico, 1969.

REMARKS: There is question if this soil contains sufficient amounts of concretions and/or nodules to classify in the Petronodic subgroup. Fragments of calcium carbonate described in the Bk1 horizon may be interpreted as concretions. The origin of these fragments needs further study before classification to the Petronodic subgroup is made.
Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 20 cm. (A horizons)
Calcic horizon: 20 to 66cm. (Bk horizon)
Paralithic contact: soft shale at 66 cm Cr horizon)

ADDITIONAL DATA: NSSL data from Guadalupe County, NM (S85NM-019-001).

TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006


National Cooperative Soil Survey
U.S.A.