LOCATION MONTAVISTA CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Typic Argixerolls
TYPICAL PEDON: Montavista clay loam, on a south east facing 25 percent slope under a cover of annual grasses and oaks at an elevation of 120 meters. When described the soil was moist throughout. (Colors are for dry soil unless otherwise noted).
A1--0 to 2 inches, (0 to 5 cm); brown (10YR 4/3) broken face clay loam, dark brown (10YR 3/3) broken face moist; 33 percent clay; strong very fine granular and strong fine granular and moderate fine subangular blocky structure; slightly hard, very friable, moderately sticky, moderately plastic; many very fine roots; many very fine interstitial pores; 10 percent rounded very strongly cemented 2 to 75 millimeter mixed rock fragments; slightly acid, pH 6.6 by pH meter 1:1 water; abrupt smooth boundary. (5 to 19 centimeters thick)
A2--2 to 9 inches, (5 to 24 cm); brown (10YR 4/3) broken face clay loam, dark brown (10YR 3/3) broken face moist; 33 percent clay; strong medium subangular blocky and strong fine subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; common very fine roots; common very fine tubular and many very fine interstitial pores; 30 percent clay films on all faces of peds; 5 percent rounded very strongly cemented 2 to 75 millimeter mixed rock fragments; slightly acid, pH 6.2 by pH meter 1:1 water; abrupt smooth boundary. (0 to 27 centimeters thick)
ABt--9 to 17 inches, (24 to 42 cm); brown (7.5YR 4/3) broken face clay loam, dark brown (7.5YR 3/3) broken face moist; 35 percent clay; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; common very fine roots; common very fine tubular pores; 60 percent clay films on all faces of peds; 5 percent rounded very strongly cemented 2 to 75 millimeter mixed rock fragments; slightly acid, pH 6.2 by pH meter 1:1 water; abrupt wavy boundary. (12 to 27 centimeters thick)
Bt1--17 to 26 inches, (42 to 67 cm); brown (7.5YR 4/4) broken face clay, brown (7.5YR 4/4) broken face moist; 45 percent clay; moderate medium subangular blocky structure; hard, firm, very sticky, very plastic; common very fine roots; common very fine tubular pores; 80 percent clay films on all faces of peds; 5 percent rounded very strongly cemented 2 to 75 millimeter mixed rock fragments; slightly acid, pH 6.5 by pH meter 1:1 water; abrupt smooth boundary. (15 to 30 centimeters thick)
Bt2--26 to 37 inches, (67 to 94 cm); strong brown (7.5YR 5/6) broken face clay loam, strong brown (7.5YR 4/6) broken face moist; 39 percent clay; moderate medium subangular blocky structure; hard, firm, very sticky, very plastic; common coarse roots; common very fine tubular pores; 80 percent clay films on all faces of peds; 5 percent rounded very strongly cemented 2 to 75 millimeter mixed rock fragments; slightly acid, pH 6.6 by pH meter 1:1 water; abrupt smooth boundary. (20 to 45 centimeters thick)
B--37 to 46 inches, (94 to 116 cm); strong brown (7.5YR 5/6) broken face clay loam, strong brown (7.5YR 4/6) broken face moist; 32 percent clay; moderate medium subangular blocky structure; hard, firm, moderately sticky, moderately plastic; common very coarse roots; common very fine tubular pores; 10 percent clay films on rock fragments; 10 percent rounded very strongly cemented 2 to 75 millimeter mixed rock fragments; slightly acid, pH 6.6 by pH meter 1:1 water; abrupt smooth boundary. (0 to 22 centimeters thick)
BC--46 to 70 inches, (116 to 178 cm); strong brown (7.5YR 5/6) broken face very gravelly sandy clay loam, strong brown (7.5YR 4/6) broken face moist; 22 percent clay; massive; slightly hard, friable, slightly sticky, slightly plastic; 50 percent rounded very strongly cemented 2 to 75 millimeter mixed rock fragments; neutral, pH 7.0 by pH meter 1:1 water; abrupt wavy boundary. (0 to 35 centimeters thick)
2B--70 to 81 inches, (178 to 205 cm); reddish yellow (7.5YR 6/6) broken face gravelly sandy clay loam, strong brown (7.5YR 5/6) broken face moist; 25 percent clay; massive; slightly hard, friable, slightly sticky, slightly plastic; 15 percent rounded very strongly cemented 2 to 75 millimeter mixed rock fragments; neutral, pH 7.2 by pH meter 1:1 water.
TYPE LOCATION: Santa Clara County, California, South of Cristo Rey Drive, Cupertino, in County park, west of creek on park trail, 20 meters down hill from trail, in an unsectionized area of Township 7s, Range 2w, 4132196 UTM Northing, 581726 UTM Easting, Zone 10, NAD83 - U.S.G.S Quad: Cupertino, California.
RANGE IN CHARACTERISTICS: Depth to Bt horizon ranges from 20 to 45 centimeters. The mean annual soil temperature is 62 to 64 degrees F. The soil moisture control section is dry in all parts from about June 15 to October 15 (about 120 days). The particle size control section averages 35 to 45 percent clay, and 5 to 15 percent rock fragments, mostly gravel. Mineralogy is mixed. The soil is non calcareous. Organic matter ranges from 1 to 3 percent to a depth of 15 centimeters. Rock fragments on the surface range from 0 to 10 percent and are gravel in size. Some pedons have a C horizon of very gravelly sandy clay loam or sandy loam.
The A and ABt horizons dry color is 10YR 4/3 or 7.5YR 4/3. Moist color is 10YR 3/3 or 7.5 YR 3/3. Texture is clay loam or sandy clay loam. Clay content ranges from 27 to 45 percent. Rock fragments range from 5 to 10 percent and are gravel in size. Reaction ranges from 6.1 to 6.6.
The Bt horizons dry color is 10YR 5/4, 5/3, 4/3, 7.5YR 6/6, 5/6 or 4/4. Moist color is 10YR 4/4, 4/3, 7.5YR 4/6 or 4/4. Texture is clay, clay loam or sandy clay loam. Clay content ranges from 35 to 45 percent. Rock fragments range from 5 to 15 percent gravel. Reaction ranges from 6.1 to 7.3.
The B, BC and 2B horizons dry color is 10YR 6/6, 6/4, 7.5YR 6/6 or 5/6. Moist color is 10YR 5/4, 4/6, 7.5YR 5/6 or 4/6. Texture is clay loam or sandy clay loam. Clay content ranges from 22 to 32 percent. Rock fragments range from 10 to 50 percent gravel. Reaction ranges from 6.6 to 7.3.
COMPETING SERIES: These are the Fagan, Gabino, Gridley, Los Osos, Marcum, Sespe, Sween and Todos soils. Fagan, Gabino, Gridley, Los Osos, Marcum, Sespe, and Todos soils have paralithic contacts between 40 and 60 inches. Sween soils have a lithic contact between 20 and 40 inches.
GEOGRAPHIC SETTING: Montavista soils are on hills of remnant terraces. Slopes are 15 to 30 percent. These soils formed in alluvium weathered from mixed rock sources. Elevation is 350 to 500 feet. Mean annual precipitation is 14 to 24 inches. The mean annual temperature is 60 to 62 degrees F. Frost free season is 275 to 325 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Flaskan, Botella and the Tarasoga(T) soils, Flaskan and Botella soils are fine loamy, Tarasoga soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: well drained; slow permeability.
USE AND VEGETATION: This soil is used for urban development and recreation. Vegetation is annual grasses and oaks.
DISTRIBUTION AND EXTENT: The soils are inextensive and are mapped in Santa Clara County. Major Land Resource Area: 14 -- Central California Coastal valleys
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Santa Clara County, California. Source of name from historical site.
REMARKS:
Particle Size Control Section for this pedon: 9.4 to 29 in. (24 to 74 cm)
Diagnostic horizons and features recognized in this pedon are:
Argillic Horizon 9 to 37 in. 24 to 94 cm
The soil moisture control section is dry in all parts from about June 15 to October 15 (about 120 days).
Pedon Notes: 07ca085641425
ADDITIONAL DATA: