LOCATION SANCARLOS CA

Tentative Series
Rev. KDA-BRY-KP
12/2022

SANCARLOS SERIES

The Sancarlos series consists of deep, well drained soils on mountain slopes. These soils formed in colluvium over residuum derived from sandstone, siltstone, and/or metasedimentary rock. Slope is 25 to 75 percent. The mean annual precipitation is about 46 centimeters (18 inches) and the mean annual temperature is about 14 degrees C. (57 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Mollic Haploxeralfs

TYPICAL PEDON: Sancarlos loam; on a northeast slope of 56 percent under blue oak, interior live oak, California foothill pine, Tucker oak, birchleaf mountain mahogany, buckbrush, California juniper, bromes, and forbs. The elevation is 813 meters (2,666 feet). (Color is for dry soil unless otherwise stated. When described on April 1, 2009 the soil was slightly moist throughout). The surface is covered by 20 percent 2 to 75 millimeter pebbles.

A1--0 to 10 centimeters (0 to 4 inches); brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine and fine tubular pores; 9 percent 2 to 75 millimeter pebbles; neutral (pH 7.3); abrupt smooth boundary.

A2--10 to 23 centimeters (4 to 9 inches); brown (10YR 4/3) clay loam, dark yellowish brown (10YR 3/4) moist; moderate fine subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; many very fine and common medium roots; common very fine tubular pores; 5 percent 2 to 75 millimeter pebbles; slightly alkaline (pH 7.5); clear wavy boundary.

Bt1--23 to 44 centimeters (9 to 17 inches); dark yellowish brown (10YR 4/4) clay loam, brown (10YR 4/3) moist; moderate fine subangular structure; slightly hard, friable, moderately sticky and very plastic; common fine, medium, and coarse roots; common very fine and fine tubular pores; few discontinuous faint clay films on faces of peds and faces along pores; 7 percent 2 to 75 millimeter pebbles; slightly alkaline (pH 7.4); clear wavy boundary.

Bt2--44 to 69 centimeters (17 to 28 inches); brown (10YR 4/3) clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular structure; hard, firm, moderately sticky and very plastic; common very fine, medium, and coarse roots; common very fine and fine tubular pores; few discontinuous faint clay films on faces of peds and surfaces along pores; 8 percent 2 to 75 millimeter pebbles and 5 percent 2 to 150 millimeter channers; slightly acid (pH 6.3); clear wavy boundary.

Bt3--69 to 79 centimeters (28 to 31 inches); brown (10YR 4/3) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate coarse subangular structure; hard, firm, very sticky and very plastic; common very fine, fine, medium, and coarse roots; common very fine tubular pores; few discontinuous faint clay films on faces of peds and surfaces along pores; 13 percent 2 to 75 millimeter pebbles and 5 percent 2 to 150 millimeter channers; neutral (pH 7.1); abrupt smooth boundary.

Bt4--79 to 132 centimeters (31 to 52 inches); brown (10YR 4/3) extremely channery clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular structure; slightly hard, friable, moderately sticky and very plastic; common very fine, fine, medium, and coarse roots; common very fine and fine tubular pores; few discontinuous faint clay films on faces of peds and surfaces along pores; 40 percent 2 to 75 millimeter pebbles, 25 percent 2 to 150 millimeter channers; neutral (pH 7.1); abrupt smooth boundary.

Cr--132 to 157 centimeters (52 to 62 inches); very weakly cemented siltstone.

TYPE LOCATION: San Benito County, California; in Clear Creek Management Area; about 2.6 kilometers (1.6 miles) west-northwest of Goat Mountain; about 671 meters (2,200 feet) north and 152 meters (500 feet) east of the southwest corner of section 15, T. 18 S., R. 11 E., Mount Diablo Base and Meridian; latitude 36 degrees 21 minutes 39.4 seconds north and longitude 120 degrees 45 minutes 44.70 seconds west; USGS Hepsedam Peak; California Quadrangle, NAD83.

RANGE IN CHARACTERISTICS:
Depth to paralithic contact is 102 to 152 centimeters (40 to 60 inches). Surface fragments are composed of siltstone, sandstone, or metasedimentary rock; 0 to 30 percent, 2 to 75 millimeter pebbles, 0 to 5 percent, 75 to 250 millimeter cobbles, 0 to 5 percent, 250 to 600 stones, and 0 to 5 percent 600 to 3000 millimeter boulders.

A horizon:
Hue: 10YR, 7.5YR, or 2.5Y dry and moist
Value: 4 to 6 dry and 3 or 4 moist
Chroma: 2 or 3 dry and moist
Texture of the fine earth fraction: loam or clay loam
Content of clay: 20 to 33 percent
Content of organic matter: 1.0 to 6.0 percent
Reaction: neutral or slightly alkaline
Content of rock fragments: 5 to 14 percent, 2 to 75 millimeter pebbles.

Bt horizons:
Hue: 10YR, 7.5YR, or 2.5Y dry and moist
Value: 4 to 6 dry and 4 or 5 moist
Chroma: 2 to 5 dry and moist
Texture of the fine earth fraction: clay loam or silty clay loam
Content of clay: 25 to 35 percent
Content of organic matter: 0.2 to 2.5 percent
Reaction: neutral or slightly alkaline
Content of rock fragments: 5 to 50 percent, 2 to 75 millimeter pebbles and 0 to 30 percent, 2 to 250 millimeter channers.

COMPETING SERIES: These are the Cranecreek, Hilt, Mary, Vannoy, and Shefflein series. Cranecreek, Hilt, Mary, and Vannoy soils are moderately deep to bedrock at a depth of 51 to 102 centimeters (20 to 40 inches). Shefflein soils are derived from granitic rocks and have mean annual precipitation of 64 to 102 centimeters (25 to 40 inches).

GEOGRAPHIC SETTING: Sancarlos soils are on mountain slopes at elevations of 730 to 1,536 meters (2,395 to 5,039 feet). Slope is 25 to 75 percent. Sancarlos soils formed in colluvium over residuum derived from sandstone, siltstone and/or metasedimentary rock. The climate consists of hot dry summers and cool moist winters. Mean annual precipitation is 432 to 610 millimeters 17 to 24 inches). Mean annual temperature is 13 to 15 degrees C. (55 to 59 degrees F). Frost-free period is 150 to 200 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Borreguero, Delmexico, Idriapeak, and Duckworth soils. Borreguero soils are shallow and have loamy particle size class. Delmexico, Idriapeak, and Duckworth soils have magnesic mineralogy.

DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for recreation and wildlife. The vegetation is blue oak, interior live oak, California foothill pine, Tucker oak, birchleaf mountain mahogany, buckbrush, California juniper, bromes, and forbs.

DISTRIBUTION AND EXTENT: These soils are in the Clear Creek Management Area, San Benito County in the California Coast Ranges. They are not extensive. MLRA 15.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES PROPOSED: San Benito County, California, 2009. Named after San Carlos Peak that is in the area.

REMARKS: The modal pedon ID for the Sancarlos Series is 09CA069001 (Pedon number 09N0920). Other supporting pedons are 90CA069063, 90CA069085, and 90CA069081.

ADDITIONAL DATA: Mean annual soil temperature at a depth of 50 cm (20 inches) is 14.5 degrees C (58 degrees F) at the typical profile site, based on 1 year's data (8/1/2009-8/1/2010) measured with an Onset Soil Temperature Recorder.

National Cooperative Soil Survey
U.S.A.