LOCATION DAPPLEGRAY CA
Established Series
RLR/GML/RLR
02/2017
DAPPLEGRAY SERIES
The Dapplegray series consists of very deep, well drained soils that formed in human-transported materials (HTM) on engineered hillslopes terraces in areas weathered from calcareous shale bedrock and other calcareous sedimentary rocks. The mean annual precipitation is about 383 mm and the mean annual temperature is about 17 degrees C.
TAXONOMIC CLASS: Fine-loamy, spolic, mixed, superactive, calcareous, thermic Typic Xerorthents
TYPICAL PEDON: Dapplegray fine sandy loam, on a hillslope terrace. (Colors are for moist soil unless otherwise noted).
^A--0 to 8 centimeters; very dark grayish brown (10YR 3/2) fine sandy loam, brown (10YR 5/3) dry; weak fine granular structure; very friable, soft, nonsticky and nonplastic; common very fine roots; common very fine interstitial pores; finely disseminated calcium carbonate; 1 percent gravel; slightly effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary. (6 to 18 cm thick)
^C--8 to 18 centimeters; light olive brown (2.5Y 5/3) fine sand, pale yellow (2.5Y 7/3) dry; single grained; loose, nonsticky and nonplastic; common very fine roots; few very fine irregular pores; finely disseminated calcium carbonate; 3 percent gravel; slightly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary.
^Cu1--18 to 58 centimeters; brown (7.5YR 4/4) gravelly sandy clay loam; moderate medium angular blocky structure; friable, hard, moderately sticky and moderately plastic; common very fine roots; common very fine irregular pores; common distinct clay films on all faces of peds; finely disseminated calcium carbonate; 25 percent gravel; 3 percent artifacts; strongly effervescent; moderately alkaline (pH 8.0); horizon structure and clay films are remnant from source material, formed prior to transport; abrupt wavy boundary.
^Cu2--58 to 90 centimeters; 70 percent dark brown (7.5YR 3/3) and 30 percent brown (7.5YR 4/4) gravelly clay loam; weak coarse subangular blocky structure; friable, very hard ; moderately sticky and moderately plastic; common very fine irregular pores; 25 percent distinct clay films on all faces of peds; finely disseminated and common medium white (10YR 8/1) masses of calcium carbonate; 20 percent gravel; 3 percent artifacts; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary.
^Cu3--90 to 140 cm; 70 percent dark brown (7.5YR 3/3) and 30 percent brown (7.5YR 4/4) gravelly clay; weak coarse subangular blocky structure; friable, very hard; very sticky and very plastic; common very fine irregular pores; many distinct clay films on all faces of peds; finely disseminated and common white (10YR 8/1) masses of calcium carbonate; 20 percent gravel; 3 percent artifacts ; strongly effervescent; moderately alkaline (pH 8.0); band of very dark brown(10YR 2/2) clay at 140 cm; abrupt wavy boundary.
^Cu4--140 to 160 cm; strong brown (7.5YR 4/6) gravelly silty clay loam; weak medium subangular blocky structure; friable, very hard ; moderately sticky and moderately plastic; common very fine irregular pores; many distinct clay films on all faces of peds; finely disseminated and common medium white (10YR 8/1) masses of calcium carbonate; 15 percent gravel; slightly effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Los Angeles County, California. Marilyn Ryan Park Sunset Park in Rancho Palos Verdes. Latitude North 33 degrees, 43 minutes, 60 seconds and longitude West 118 degrees, 20 minutes, 54 seconds, WGS84 - U.S.G.S Quad: San Pedro.
RANGE IN CHARACTERISTICS:
Soil moisture: moist below a depth of about 30 cm some time from October to December and remains moist in some part between depths of about 30 to 90 cm until April or May.
Mean annual soil temperature: 17 to 20 degrees C.
Human-transported materials: typically greater than 100 cm, often greater than 200 cm thick.
Rock fragments: typically 10 to 35 percent, transported from the source material or are detached fragments from in-situ bedrock. Some pedons have less than 10 percent fragments.
Reaction: neutral to moderately alkaline.
Artifacts: 0 to 10 percent, construction debris.
^A(u) horizons:
Dry color: hue of 2.5Y or 10YR, value of 3 to 6, chroma of 2 or 3.
Moist color: hue of 2.5Y or 10YR, value of 2 to 5, chroma of 1 to 3.
Texture: fine sandy loam, loam or silt loam.
Clay content: 18 to 35 percent.
Rock fragments: 0 to 15 percent.
Artifacts: 0 to 10 percent, construction debris.
^C(u) horizons:
Color: hue of 2.5Y, 10YR or 7.5YR, value of 4 to 7, chroma of 2 to 6.
Texture: loam, sandy loam, sandy clay loam, silt loam or clay loam.
Clay content: 18 to 35 percent.
Rock fragments: 0 to 35 percent, transported from the source material or are detached fragments from in-situ bedrock.
Artifacts: 0 to 10 percent construction debris with individual horizons containing 10 to 25 percent.
COMPETING SERIES:
Sepulveda soils: typically have less than 10 percent rock fragments and originates from sedimentary alluvium on remnant alluvial fans and uplifted alluvium.
GEOGRAPHIC SETTING:
Landscape: hills and mountains.
Landform: cut and fill hillslope terraces, leveled land, graded areas of developed hillsides.
Parent material: human-transported materials originating from material weathered from calcareous shale and other sedimentary rocks.
Elevation: 5 to 455 meters
Slope: 0 to 15 percent on treads and graded slopes, up to 60 percent on risers.
Climate: warm dry summers and cool moist winter.
Mean annual precipitation: 280 to 500 mm.
Mean January temperature: 14 degrees C.
Mean July temperature: 20 degrees C.
Mean annual temperature: 16 to 19 degrees C.
Frost free season: 300 to 365 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Apollo soils: have a paralithic contact at a depth of 100 to 150 cm and occur on natural hillslopes.
Balcom soils: have a calcic horizon and occur on natural hillslopes.
Counterfeit soils: have greater than 35 percent clay and occur on similar landscapes.
Filiorum soils: have greater than 35 percent clay and occur on marine terraces.
Lunada soils: have greater than 35 percent rock fragments occur on steep canyon side slopes and hillslopes.
Marina soils: have sandy textures and lamellae and occur on coastal sand dunes.
Montebello soils: are human transported soils that originate from alluvium weathered from granitic sources and occur on graded, remnant alluvial fans.
Nacimiento soil: have a paralithic contact within a depth 100 cm and occur on natural hillslopes.
Oceanaire soils: have an argillic horizon and occurs on natural hillslopes.
Windfetch soils: have an argillic horizon and occurs on uplifted alluvium and terraces.
Zaca soils: have greater than 35 percent clay and occurs on natural hillslopes.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to very high runoff; moderate saturated hydraulic conductivity.
USE AND VEGETATION: Dapplegray soils are used for residential neighborhoods in urban areas. Vegetation is ornamental plants, succulents and lawns.
DISTRIBUTION AND EXTENT: Coastal hills, foot hills, and low mountains of southern California mountains; MLRA 20. These soils are of moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Los Angeles County, California, 2016.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from a depth of 0 to 8 cm.
Artifacts - the zone from a depth of 18 to 140 cm.
Human-transported materials - the zone from a depth of 0 to 160 cm.
Particle-size control section - the zone from a depth of 25 to 100 cm.
Some pedons have sandy textured horizons near the surface to improve drainage and infiltration. Soil structure and secondary carbonate in the human-transported materials are considered geogenic and not pedongenic in nature having been formed prior to transport of material. Some pedons also have clay films that are discontinuous and not oriented.
Taxonomic subgroup tagged as typic due to presence of human-transported materials. The soil has occurs on appropriate landforms and has soil properties that support the concept of human-transported materials. The use of the Anthroportic subgroup is not currently permitted in the xeric soil moisture regime, but will be explored for future consideration for correlation.
ADDITIONAL DATA:
User site ID: 2015CA6961231
Classified using the Twelfth Edition Keys to Soil Taxonomy (2014)
National Cooperative Soil Survey
U.S.A.