LOCATION CHILOJO            NM
Inactive Series
Rev. CDH/WMR
07/2005

CHILOJO SERIES


The Chilojo series consists of well drained soils that are very deep to a densic contact. They formed in alluvium derived from sandstone and shale. Chilojo soils are on footslopes of undulating plateaus. Slopes are 1 to 5 percent. Mean annual precipitation is about 13 inches and mean annual temperature is about 50 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ustic Haplargids

TYPICAL PEDON: Chilojo loam--on a footslope of an undulating plateau sloping 4 percent to the south at 6,990 feet elevation. (Colors are for dry soil unless otherwise noted. When described on September 9, 2002, the soil was moist 0 to 7 inches and otherwise dry throughout.)

A--0 to 2 inches; reddish brown (5YR 4/4) fine sandy loam, dark reddish brown (5YR 3/4) moist; weak fine granular structure; soft, very friable, slightly sticky and nonplastic; few fine and common very fine roots; many very fine irregularly shaped pores; 3 percent gravel; slightly effervescent (1 percent calcium carbonate equivalent); moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 3 inches thick)

Bt--2 to 9 inches; yellowish red (5YR 4/6) loam, dark reddish brown (5YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and common very fine roots; common fine irregularly shaped and few very fine tubular pores; few distinct and common faint clay films on faces of peds and lining pores; 3 percent gravel; slightly effervescent (1 percent calcium carbonate equivalent); moderately alkaline (pH 8.0); clear smooth boundary. (5 to 10 inches thick)

Btk1--9 to 16 inches; reddish brown (2.5YR 5/4) loam, dark red (2.5YR 3/6) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine roots; few medium and few fine tubular pores; common distinct clay films lining pores and few distinct and few faint clay films on faces of peds; 5 percent gravel; strongly effervescent, secondary calcium carbonates segregated as few medium irregularly shaped coatings on faces of peds (3 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); gradual wavy boundary.

Btk2--16 to 29 inches; reddish brown (2.5YR 5/4) gravelly clay loam, dark red (2.5YR 3/6) moist; moderate coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; few medium and common fine tubular pores; few distinct and common faint clay films on faces of peds and lining pores; 15 percent gravel; violently effervescent, secondary calcium carbonates segregated as common medium irregularly shaped coatings on faces of peds (5 percent calcium carbonate equivalent); strongly alkaline (pH 8.6); clear smooth boundary. (Combined thickness of the Btk horizons is 15 to 24 inches)

Bk1--29 to 38 inches; reddish brown (2.5YR 5/4) gravelly clay loam, dark red (2.5YR 3/6) moist; massive; hard, firm, moderately sticky and slightly plastic; common very fine roots; few very fine tubular pores; 20 percent gravel and 10 percent cobbles; 30 percent paragravel; violently effervescent, secondary calcium carbonates segregated as few fine and medium irregularly shaped coatings on faces of peds (9 percent calcium carbonate equivalent); strongly alkaline (pH 8.6); clear smooth boundary.

2Bk2--38 to 46 inches; red (2.5YR 4/6) clay loam, dark red (2.5YR 3/6) moist; massive; slightly hard, friable, moderately sticky and slightly plastic; common very fine roots; few very fine tubular pores; 5 percent gravel; 10 percent paragravel; violently effervescent, secondary calcium carbonates segregated as few fine irregularly shaped coatings on faces of peds (8 percent calcium carbonate equivalent); moderately alkaline (pH 8.4); clear smooth boundary.

2Ctk--46 to 61 inches; red (2.5YR 4/6) very paragravelly clay loam, red (2.5YR 4/8) moist; massive; slightly hard, friable, moderately sticky and slightly plastic; common very fine roots; many distinct clay films on pararock fragments; 50 percent paragravel; non to strongly effervescent, secondary calcium carbonates segregated as few fine irregularly shaped coatings on faces of peds (4 percent calcium carbonate equivalent); moderately alkaline (pH 8.4); abrupt smooth boundary.

2Cd--61 to 80 inches; noncemented densic contact

TYPE LOCATION: Santa Fe County, New Mexico, about 6.5 miles south-southeast of White Lakes; 150 feet east and 138 feet north of the southwest corner of section 2, T.10N., R.11E.; USGS El Cuervo Butte 7.5 minute topographic quadrangle; Latitude 35 degrees 6 minutes 50 seconds North and Longitude 105 degrees 44 minutes 57 seconds West, NAD 27.

RANGE IN CHARACTERISTICS:

Soil moisture - The soil moisture control section (SMCS) is intermittently moist in some part from July to October and December to March. Additional run-on occurs from July through September. The soils are driest in May and June. The soil moisture regime is an aridic moisture regime bordering on ustic.

Soil temperature - 51 to 53 degrees F.
Depth to base of ochric epipedon - 1 to 3 inches
Depth to base of argillic horizon - 25 to 40 inches

Particle-size control section weighted averages:
Silicate clay content: 20 to 30 percent
Sand content: 30 to 45 percent
Fine sand or coarser content: 25 to 40 percent
Rock fragment content: 0 to 5 percent gravel percent in the upper part and 15 to 25 percent in the lower part

Salinity: dS/m - 0 to 2
Sodicity: SAR - 0 to 4

A horizon
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 4 or 6, dry or moist

Bt horizon
Hue: 2.5YR or 5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 4 or 5, dry or moist
Texture: loam or clay loam
Clay content: 20 to 30 percent
Rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 0 to 1 percent

Btk horizons
Hue: 2.5YR or 5YR
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 4 or 6, dry or moist
Texture: loam, clay loam, gravelly loam, or gravelly clay loam
Clay content: 22 to 30 percent
Rock fragments: 5 to 25 percent gravel
Calcium carbonate equivalent: 3 to 10 percent

Bk horizon
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 4 or 6, dry or moist
Texture: loam, clay loam, gravelly loam, or gravelly clay loam
Clay content: 20 to 30 percent
Rock fragments: total range is 5 to 35 percent
5 to 25 percent gravel
0 to 10 percent cobbles
Pararock fragments: 15 to 35 percent paragravel
Calcium carbonate equivalent: 5 to 10 percent

2Ctk horizon
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 4 or 6, dry or moist
Texture: very paragravelly loam or very paragravelly clay loam
Clay content: 25 to 35 percent
Pararock fragments: 35 to 60 percent paragravel
Calcium carbonate equivalent: 1 to 5 percent

COMPETING SERIES: These are the Balon, Blancot, Bowbac, Buckle, Cambria, Cushman, Decolney, Doakum, Forkwood, Fort, Gapbutte, Gapmesa, Hagerman, Hagerwest, Hiland, Los Alamos, Mentmore, Oelop, Olney, Palacid, Penistaja, Pokeman, Potts, Pugsley, Quagwa, Redpen, Spangler, Spenlo, Sundance, Tamarindo, Teckla, and Yenlo series. None of these series are over a densic contact.

Balon, Blancot, and Yenlo do not have visible secondary carbonates in the argillic horizon. Bowbac, Cambria, Cushman, Decolney, Forkwood, Fort, Hiland, Olney, Pokeman, Potts, Pugsley, Spangler, and Teckla soils are more moist in May and June.
Buckle, Los Alamos, Mentmore, and Quagwa soils have hues of 7.5 YR or yellower.
Spenlo soils have a calcic horizon and should be reclassified as a Calciargid.
Doakum, Oelop, Palacid, Penistaja, and Redpen soils do not have a densic contact within 80 inches.
Gapbutte, Gapmesa, Hagerman, and Hagerwest soils are moderately deep.
Tamarindo soils are greater than 40 inches to the base of the argillic.

A series that would be a competitor if assigned a superactive activity class is the Gaddes series. Gaddes soils are moderately deep to a paralithic contact of weathered granite.

GEOGRAPHIC SETTING: Chilojo soils are on footslopes of undulating plateaus. They formed in alluvium derived from sandstone and shale of the Triassic Age Chinle Formation. Slopes are 1 to 5 percent. Elevation ranges from 6,300 to 7,100 feet. The mean annual precipitation is 12 to 14 inches with about 45 percent falling as rain from high-intensity convective thunderstorms between July and September. The mean annual air temperature is 49 to 51 degrees F. The frost-free period is 130 to 150 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arojomil, Clovis, Ildefonso, and Kinsell soils. Arojomil soils are moderately deep to a petrocalcic horizon and are on summits and shoulders of undulating plateaus. Clovis soils have a calcic horizon and occur on backslopes and footslopes. Ildefonso soils are loamy-skeletal, have a calcic horizon, and occur on shoulders and backslopes. Kinsell soils are fine-silty, have a mollic epipedon, and are on floodplains and channels of valley floors.

DRAINAGE AND PERMEABILITY: Well drained; runoff is medium; permeability is moderately slow.

USE AND VEGETATION: Chilojo soils are used for livestock grazing, recreation, and wildlife habitat. Present vegetation is blue grama, sand dropseed, galleta, ring muhly, bud sagebrush, Bigelow sagebrush, tree cholla, and whipple cholla.

DISTRIBUTION AND EXTENT: Chilojo soils are of small extent in the northeastern part of the Estancia Basin in the Mexican Highland section of the Basin and Range physiographic province in northcentral New Mexico, MLRA 70.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas.

SERIES PROPOSED: Santa Fe County, New Mexico; Santa Fe Area Soil Survey Update; 2002. Chilojo is a coined name.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - The zone from 0 to a depth of about 2 inches. (A horizon)
Argillic horizon - The zone from 2 to about 29 inches. (Bt, Btk1, and Btk2 horizons)
Densic contact - The presence of a hard noncemented contact at 61 inches (2Cd horizon)

Classified according to Soil Taxonomy Second Edition, 1999.

ADDITIONAL DATA: Calcium carbonate equivalence was determined using a field calcimeter.


National Cooperative Soil Survey
U.S.A.