LOCATION CHINAPOINT CA
Established Series
DCE/RLR/ET
04/2019
CHINAPOINT SERIES
The Chinapoint series consists of moderately deep, well drained soils that formed in fine alluvium derived from mixed rock sources. Chinapoint soils are on hills and terraces and have slopes of 2 to 30 percent. The mean annual precipitation is about 255 millimeters (about 10 inches) and the mean annual temperature is about 17.5 degrees C. (63.5 degrees F.).
TAXONOMIC CLASS: Fine, smectitic, thermic Sodic Haploxererts
TYPICAL PEDON: Chinapoint silt loam - on a 5 percent slope under a cover of slender oats, soft chess, stipa and clover at 305 meters (1,000 feet) elevation. (Colors are for dry soil unless otherwise stated. When described on May 5, 1982, the soil was slightly moist at 5 to 18 centimeters (2 to 7 inches) and was moist below 18 centimeters (7 inches).
E--0 to 5 centimeters (0 to 2 inches); gray (10YR 5/1) silt loam, very dark gray (10YR 3/1) moist; moderate coarse angular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine roots; many very fine interstitial and tubular pores; cracks are 1/2 to 2 centimeters wide; neutral (pH 7.0); abrupt smooth boundary. (0 to 10 centimeters; 0 to 4 inches thick)
A--5 to 18 centimeters (2 to 7 inches); dark grayish brown (10YR 4/2) clay, very dark brown (10YR 2/2) with coatings of black (10YR 2/1) moist; moderate medium prismatic and weak medium and coarse angular blocky structure; very hard, friable, very sticky and very plastic; many very fine and few fine roots; common very fine tubular pores; cracks are 1/2 to 2 centimeters wide; slightly alkaline (pH 7.5); clear wavy boundary. (10 to 15 centimeters; 4 to 6 inches thick)
An1--18 to 51 centimeters (7 to 20 inches); dark grayish brown (10YR 4/2) clay, very dark brown (10YR 2/2) with coatings of black (10YR 2/1) moist; strong medium and coarse prismatic structure; extremely hard, friable, very sticky and very plastic; common very fine roots, common very fine tubular pores; common wedge shaped aggregates; SAR is 25; cracks 1/2 to 2 centimeters wide; moderately alkaline (pH 8.0); gradual wavy boundary. (25 to 38 centimeters; 10 to 15 inches thick)
An2--51 to 86 centimeters (20 to 34 inches); dark grayish brown (10YR 4/2) clay, very dark brown (10YR 2/2) with coatings of black (10YR 2/1) moist; strong coarse and very coarse prismatic structure; extremely hard, friable, very sticky and very plastic; common very fine roots; common very fine tubular pores; SAR is 30; common wedge shaped aggregates; cracks 1/2 to 1 centimeters wide; moderately alkaline (pH 8.0); abrupt wavy boundary. (25 to 41 centimeters; 10 to 16 inches thick)
2Cr--86 to 119 centimeters (34 to 47 inches); yellowish brown (10YR 5/4) semiconsolidated sands, that crushes to a loamy coarse sand.
TYPE LOCATION: San Clemente Island, Los Angeles County, California; about 1.1 miles going southeast from the intersection of Main Road and road leading to Magazine Area and Eel Point, about 700 feet northwest from the intersection of Main Road and Nanny Road, and then about 100 feet west to site; 32.9806 degrees latitude, -118.55056 degrees longitude; UTM zone 11, 355114.19e, 3650203.68n; U.S.G.S. Quad: San Clemente Island Central, California.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 18 to 18.5 degrees C. (65 degrees F.)
Soil moisture and cracks: when dry, the soil forms cracks about 1 to 5 cm wide that extend from the surface to the paralithic contact and remain closed from late December to late March or early April.
Depth to a paralithic contact: 50 to 100 centimeters (20 to 40 inches) to weakly consolidated sands.
Slickensides: some pedons have few and intersecting from 18 to 86 cm (7 to 34 inches).
Surface rock fragments: 0 to 5 percent stones, 0 to 25 percent cobbles and 5 to 10 percent gravel.
Exchangeable sodium percentage (SAR): 25 to 30 percent.
Electrical conductivity (EC): 4 to 16 ds/m in the lower part.
Clay content: 40 to 60 percent.
E horizon: (where it occurs):
Texture: silt loam, loam or is clay when the upper 18 centimeters (7 inches) is mixed.
A horizon:
Dry color: 10YR 5/2 or 4/2
Moist color is 10YR 3/2 or 2/2
Texture: clay
Reaction: slightly acid or neutral in the upper part and is neutral to moderate alkaline in the lower part.
Calcium carbonate: some pedons have finely disseminated calcium carbonate or fine calcium carbonate masses in the layer above a paralithic contact.
2Cr horizon: weakly consolidated massive sands.
COMPETING SERIES:
Alcapay soils: do not have a paralithic contact and are found in level basins.
Lostpoint soils: are deep to a paralithic contact and are on similar landscape positions.
Tranquillity soils: are somewhat poorly drained and are on fan skirts.
GEOGRAPHIC SETTING:
Landscape: islands
Landforms: hills and terraces.
Slope: 2 to 30 percent.
Parent material: fine alluvium derived from mixed rock sources.
Elevations: 200 to 365 meters (650 to 1200 feet).
Climate: maritime with warm foggy dry summers and cool moist winters.
Mean annual precipitation: 254 millimeters (10 inches).
Mean January temperature: 12.2 degrees C. (54 degrees F.)
Mean July temperature: 19.4 degrees C. (67 degrees F.)
Mean annual temperature: 16 to 18 degrees C. (61 to 64 degrees F.)
Frost-free season: 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
Eelpoint soils: are moderately-deep to a lithic contact and are on similar landforms.
Notspier soils: have an ustic moisture regime and are on similar landforms.
Shoba soils: have an argillic horizon, are moderately-deep to a lithic contact and are on hills or mountains.
Thirst soils: are shallow to a lithic contact and are on hills or mountains.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, medium to very high runoff, low saturated hydraulic conductivity.
USE AND VEGETATION: This soil is used mainly for military maneuvers and to a minor extent for wildlife habitat. The vegetation is slender oats, stipa, australian saltbush and soft chess.
DISTRIBUTION AND EXTENT: Channel Islands area at San Clemente Island; Southern California Mountains, MLRA 20. These soils are not extensive.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Clemente Island, Los Angeles County, California, 1982. Series name is for China Point at the Southwest tip of the Island.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from a depth of 0 to 18 centimeters
Paralithic contact - at a depth of 86 centimeters
Paralithic materials - the zone from a depth of 86 to 111 centimeters
Original taxonomic classification in 1982 San Clemente Interim report was Fine, montmorillonitic, thermic Typic Chromoxererts.
OSD revised during correlation of the San Clemente Island Interim Report in 2018.
ADDITIONAL DATA:
NASIS User Site/Pedon ID: 1982CA037CHINAPOINT
Classified using the Twelfth Edition Keys to Soil Taxonomy (2014)
National Cooperative Soil Survey
U.S.A.