LOCATION OAKZANITA               CA

Tentative Series
Rev. TCM/RLR
07/2022

OAKZANITA SERIES

The Oakzanita series consists of deep, well drained soils that formed in colluvium and residuum derived from material weathering from gabbro and other igneous rocks. Oakzanita soils are on hillslopes and mountain slopes and have slopes of 5 to 60 percent. The mean annual precipitation is about 720 millimeters and the mean annual air temperature is about 13 degrees C.

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

TYPICAL PEDON: Oakzanita soils in an area of Oakzanita gravelly loam on a slope of 26 percent facing south at an elevation of 1480 meters under a cover of chamise, mountain mahogany, and buckwheat. (Colors are for dry soil unless otherwise noted). The surface is covered by approximately 30 percent fine gravel and 15 percent medium gravel.

A--0 to 22 centimeters; brown (7.5YR 4/2) gravelly loam, dark brown (7.5YR 3/2), moist; moderate fine subangular block structure; very friable, slightly hard, moderately sticky, slightly plastic; common fine roots; common fine tubular and interstitial pores; neutral (pH 6.8); clear wavy boundary. (10 to 24 cm thick)

2Bt1--22 to 55 centimeters; red (2.5YR 4/6) clay loam, reddish brown (2.5YR 4/4), moist; moderate medium subangular blocky structure; friable, extremely hard, very sticky, very plastic; few very fine roots; common fine tubular pores; many distinct clay films on faces of peds; neutral (pH 7.0); clear wavy boundary. (12 to 25 cm thick)

2Bt2--55 to 73 centimeters; red (2.5YR 4/6) clay loam, red (2.5YR 4/6), moist; strong medium subangular blocky structure; friable, extremely hard, very sticky, very plastic; very few fine roots; common fine and medium tubular pores; many distinct clay films on faces of peds; neutral (pH 7.0); clear wavy boundary. (20 to 30 cm thick)

2BCt--73 to 110 centimeters; yellowish red (5YR 5/6) clay loam, yellowish red (5YR 4/6), moist; weak medium subangular blocky structure; friable, extremely hard, moderately sticky, moderately plastic; few very fine roots; few medium and many fine tubular pores; many distinct clay films on faces of peds; neutral (pH 7.0); clear gradual wavy boundary. (10 to 30 cm thick)

2Cr--110 to 150 centimeters; moderately cemented gabbro-diorite rock


TYPE LOCATION: San Diego County, California; approximately 300 meters west of East Mesa Fire Road and 320 meters north of North Descanso Creek Trail in Cuyamaca Rancho State Park, about 300 meters west and 280 meters north of the northwest corner of section 11, T15S, R04E; 32.89231 degrees latitude, -116.5553 degrees longitude WGS84; UTM Zone 11, 3639436n, 541592e. U.S.G.S Quad Name: Cuyamaca Peak, California

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 13 degrees C.
Soil moisture: Usually dry in all parts from late May or early June until late November or early December, and usually moist in some or all parts the rest of the year.

Rock fragments: 0 to 25 percent gravel throughout
Reaction: slightly acid to neutral throughout.
Clay content: 25 to 35 percent by average in the particle-size control section.

A horizon:
Dry color: 10YR or 7.5YR 4/2, 4/3, 5/3, 5/2
Moist color: 10YR or 7.5YR 2/2, 3/2, 3/3
Texture: sandy loam, fine sandy loam, loam
Clay content: 8 to 18 percent
Rock fragments: 5 to 25 percent gravel
Organic matter content: 1 to 3 percent

B horizons:
Dry color: 10YR 6/4, 7.5YR or 5YR 6/6, 5/6, 6/4, 4/4
Moist color: 7.5YR or 5YR 4/4, 3/4, 4/6
Texture: sandy clay loam, clay loam, loam
Clay content: 24 to 35 percent
Rock fragments: 0 to 5 percent gravel

BC horizon
Dry color: 7.5YR, 5YR 5/6, 6/4, 4/6
Moist color: 7.5YR, 5YR 5/4, 4/4, 4/6
Texture: loamy sand, sandy loam, very fine sandy loam and is typically stratified; some pedons have lenses of clay loam.
Clay content: 10 to 30 percent
Rock fragments: 0 to 10 percent gravel

COMPETING SERIES:
Bancas soils: 50 to 100 centimeters to a paralithic contact of igneous rock
Bull Trail soils: 18 to 27 percent clay in the particle control section
Cranecreek soils: 50 to 100 centimeters to a paralithic contact of basic igneous rock
Hilt soils: 50 to 100 centimeters to a lithic contact of sandstone
Ipish soils: Ca:Mg ratio is 1 or less
Mary soils: 50 to 100 centimeters to a lithic contact of extrusive igneous rock
San Carlos soils: greater than 20 percent clay in the A horizons
Shefflein soils: 15 to 40 percent coarse or very coarse sand in the particle control section
Vannoy soils: 50 to 100 centimeters to a paralithic contact of metamorphosed bedrock

GEOGRAPHIC SETTING:
Landscape: coastal plains and valleys and canyons
Landform: hillslopes and mountain slopes
Parent Material: colluvium over residuum weathered from gabbro and other intrusive igneous rocks
Slope: 5 to 60 percent slopes
Elevation: 1180 to 1540 meters
Mean annual precipitation: 650 to 760 mm
Mean January temperature: 6 degrees C.
Mean July temperature: 22 degrees C.
Mean annual temperature: 12.0 to 13.8 degrees C.
Frost-free season: 180 to 200 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Bancas soils: 50 to 100 centimeters to a paralithic contact of igneous rock
Crouch soils: less than 18 percent clay in the particle control section
Tollhouse soils: 25 to 50 centimeters to a paralithic contact of diorite
Cieneba soils: 25 to 50 centimeters to a lithic contact of diorite
Holland soils: greater than 150 centimeters to a lithic contact

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderate to moderately slow saturated hydraulic conductivity.

USE AND VEGETATION: Used for wildlife and recreation. Native vegetation is chamise, ceanothus, mountain mahogany, coffeeberry, California buckwheat, yucca, and white sage.

DISTRIBUTION AND EXTENT: Southern California Coastal Plains and Mountains, MLRA 19. This soil is moderately extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: San Diego County, California 2022.

REMARKS:

Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon: the zone from 0 to 22 cm
Argillic horizon: the zone from 22 to 110 cm
Lithologic discontinuity: the zone from 22 to 110 cm
Paralithic contact: 110 centimeters
Paralithic materials: the zone from 110 to 150 cm
Particle-size control section: the zone from 22 to 72 cm


ADDITIONAL DATA:

NASIS User Site/Pedon ID: 2019CA073002

Classified using the Twelfth Edition Keys to Soil Taxonomy (2014)

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National Cooperative Soil Survey
U.S.A.