LOCATION LUCITO NMTentative Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, frigid Pachic Argiustolls
TYPICAL PEDON: Lucito loam--on a toeslope of a mountain sloping 2 percent to the south-southwest at 8,895 feet elevation-mixed conifer forestland. (Colors are for dry soil unless otherwise noted. When described on July 14, 2000, the soil was moist from 22 to 45 inches and otherwise dry.)
Oe--0 to 1 inch (0 to 3 cm); moderately decomposed roots and leaves; abrupt smooth boundary. (1 to 2 inches thick)
A1--1 to 4 inches (3 to 10 cm); dark gray (10YR 4/1) loam, black (10YR 2/1) moist; moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and many very fine roots; few fine tubular pores; 5 percent gravel and 1 percent boulders; slightly acid (pH 6.4); clear wavy boundary. (2 to 9 inches thick)
A2--4 to 11 inches (10 to 28 cm); very dark gray (10YR 3/1) loam, black (10YR 2/1) moist; moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; common medium, many fine, and many very fine roots; common coarse and common fine tubular pores; 5 percent gravel and 1 percent boulders; slightly acid (pH 6.4); clear wavy boundary. (7 to 10 inches thick)
A3--11 to 22 inches (28 to 56 cm); very dark gray (10YR 3/1) cobbly loam, black (10YR 2/1) moist; moderate medium subangular blocky structure; moderately hard, firm, slightly sticky and slightly plastic; common very coarse, few medium, few fine, and few very fine roots; common fine tubular pores; 10 percent gravel, 10 percent cobbles, and 1 percent boulders; slightly acid (pH 6.2); clear smooth boundary. (0 to 6 inches thick)
E/B1--22 to 29 inches (56 to 74 cm); 80 percent light brownish gray (10YR 6/2) very cobbly loam (E), grayish brown (10YR 5/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and few very fine roots; common very fine tubular pores; 20 percent light brown (7.5YR 6/4) very cobbly loam (B), brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; moderately hard, firm, moderately sticky and slightly plastic; common fine and few very fine roots; common very fine tubular pores; few faint clay films on faces of peds; peds of Bt are surrounded by E material 20 to 40 mm thick; 20 percent gravel, 30 percent cobbles, and 1 percent boulders; slightly acid (pH 6.2);clear wavy boundary. (6 to 22 inches thick)
E/B2--29 to 37 inches (74 to 94 cm); 60 percent light gray (10YR 7/2) very cobbly loam (E), brown (10YR 5/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; few very fine tubular pores; 40 percent light brown (7.5YR 6/4) very cobbly loam (B), brown (7.5YR 5/4) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few fine roots; few very fine tubular pores; common distinct and few faint clay films on faces of peds; peds of Bt are surrounded by E material 10 to 30 mm thick; 20 percent gravel, 35 percent cobbles, and 1 percent boulders; neutral (pH 6.8); clear wavy boundary. (0 to 12 inches thick)
Bt--37 to 82 inches (94 to 208 cm); light yellowish brown (10YR 6/4) very cobbly clay, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; moderately hard, friable, moderately sticky and very plastic; few very fine tubular pores, common distinct and common faint clay films on faces of peds, 25 percent gravel, 30 percent cobbles, and 3 percent boulders; neutral (pH 6.8).
TYPE LOCATION: Bandelier National Monument, Sandoval County, New Mexico; about 6 miles west-southwest of Los Alamos; Bland 7.5 minute topographic quadrangle; Latitude 35 degrees 50 minutes 3.85 seconds North and Longitude 106 degrees 25 minutes 55.41 seconds West, NAD 27.
RANGE IN CHARACTERISTICS: (Depths given are measured from the mineral soil surface)
Soil moisture: 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 dry in all parts less than 40 percent of the time and dry in some or all parts more than 105 cumulative days when the soil temperature at 20 inches (50 cm) is above 41 degrees F. The soil moisture regime is typic ustic.
Mean annual soil temperature: 42 to 45 degrees F
Depth to the base of the mollic epipedon: 16 to 27 inches
Depth to top of argillic horizon: 17 to 37 inches
Depth to base of argillic horizon: greater than 60 inches
Organic matter content: 1 to 3 percent in the mollic epipedon
Lithology of rock fragments: Dacite and latite
Volcanic glass content: 5 to 15 percent in the coarse silt plus sand fraction (estimated)
Particle-size control section (weighted averages)
Silicate clay content: 35 to 50 percent
Sand content: 15 to 30 percent
Fine sand or coarser content: 10 to 20 percent
Rock fragment content: 45 to 80 percent
A1 horizon
Value: 3 or 4 dry
Chroma: 1 or 2 moist
Clay content: 18 to 27 percent
Base saturation: 75 to 95 percent
Rock fragments: total range is 0 to 14 percent
0 to 10 percent gravel
0 to 5 percent boulders
Lower A horizons
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3, dry moist
Texture: loam, cobbly loam, gravelly loam
Clay content: 18 to 27 percent
Base saturation: 70 to 95 percent
Rock fragments: total range is 0 to 20 percent
0 to 10 percent gravel
0 to 10 percent cobbles
0 to 5 percent boulders
E/B horizons
E part
Value: 6 to 8 dry, 5 to 7 moist
Chroma: 2 or 3, dry or moist
Clay content: 20 to 26 percent
B part
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 3 or 4, dry or moist
Texture: very cobbly loam or very cobbly clay loam
Clay content: 24 to 30 percent
Base saturation: 65 to 90 percent
Rock fragments: total range is 35 to 60 percent
15 to 25 percent gravel
20 to 40 percent cobbles
0 to 5 percent stones
0 to 5 percent boulders
Bt horizons
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 to 4, dry or moist
Texture: extremely cobbly clay, very cobbly clay, extremely cobbly clay loam, very cobbly clay loam
Clay content: 35 to 50 percent
Base saturation: 60 to 85 percent
Rock fragments: total range is 50 to 80
10 to 25 percent gravel
30 to 50 percent cobbles
0 to 10 percent stones
0 to 10 percent boulders
COMPETING SERIES: There are no competing series. A similar soil in another family is the Rionutria series. Rionutria soils are moderately deep and have mollic epipedons that are not pachic
GEOGRAPHIC SETTING: Lucito soils are on toeslopes and footslopes of mountains, and on summits of plateaus. They formed in slope alluvium derived from latite and dacite of the Tertiary age Tschicoma Formation. Slopes are 1 to 8 percent. Elevation ranges from 8,800 to 9,500 feet. The mean annual precipitation is 24 to 28 inches with about 45 percent falling as rain from high-intensity convective thunderstorms between July and September. The mean annual air temperature is 41 to 43 degrees F. The frost-free period is 100 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Estaban and Mapache soils. Estaban soils are fragmental, have a cambic horizon, and occur on backslopes of canyons. Mapache soils are loamy-skeletal, do not have an argillic horizon, and occur on backslopes and footslopes of mountains.
DRAINAGE AND PERMEABILITY: Well drained; medium surface runoff; slow permeability.
USE AND VEGETATION: Lucito soils are used for recreation and wildlife habitat. Present vegetation is quaking aspen, white fir, Douglas fir, Parry's oatgrass, nodding brome, Thurber's fescue, bottlebrush squirreltail, American vetch, bluebell bellflower, and nodding onion.
DISTRIBUTION AND EXTENT: Lucito soils are of small extent on the Jemez Volcanic Field part of the Southern Rocky Mountains province in northcentral New Mexico. The MLRA is 48A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Sandoval County, New Mexico; Bandelier National Monument Soil Survey; 2000. Lucito is a place name.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon- The zone from 1 to 22 inches. (A1, A2, and A3 horizons)
Glossic horizon - The zone from 22 to 37 inches (E/B1 and E/B2 horizons)
Argillic horizon - The zone from 37 to 82 inches. (Bt horizon)
Particle-size control section - The zone from 37 to 57 inches (upper part of the Bt horizon)
This soil may have a udic ustic moisture regime subclass rather than typic ustic. Further study is needed.
Classified according to Soil Taxonomy Second Edition, 1999.