LOCATION EELCOVE                 CA

Established Series
JFR/DCE/RLR
04/2019

EELCOVE SERIES

The Eelcove series consists of deep, well drained soils that formed in fine alluvium derived from mixed rock sources. Eelcove soils are on marine terraces and have slopes of 2 to 9 percent. The mean annual precipitation is about 235 millimeters (9 inches) and the mean annual temperature is about 17 degrees C. (62.5 degrees F.).

TAXONOMIC CLASS: Fine, smectitic, isothermic Typic Natrustalfs

TYPICAL PEDON: Eelcove cobbly silt loam, on a marine terrace of 2 percent slope under a cover of cholla, Australian saltbush, boxthorn and red brome at about 15 meters (50 feet) elevation. When described on September 9, 1981 the soil was dry to 60 cm (24 inches) and slightly moist below. (Colors are for dry soil unless otherwise noted.)

En--0 to 10 centimeters (0 to 4 inches); light brownish gray (10YR 6/2) cobbly silt loam, dark grayish brown (10YR 4/2) moist; moderate thick and very thick platy structure; hard, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; many very fine and few fine tubular pores; ESP is 11; 3 percent stones, 10 percent cobbles and 5 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (3 to 13 centimeters; 1 to 5 inches thick)

Btn1--10 to 30 centimeters (4 to 12 inches); light brownish gray (10YR 6/2) clay, dark grayish brown (10YR 4/2) moist; strong fine and medium prismatic parting to moderate medium angular blocky structure; very hard, friable, very sticky and very plastic; many very fine and few fine roots mostly along faces of prisms; many very fine tubular pores; 5 percent cobbles and 5 percent gravel; common faint and few distinct clay films on peds and lining pores; cracks are about 3 to 8 millimeters wide and 20 to 30 centimeters apart; ESP is 40; moderately alkaline (pH 8.0); clear wavy boundary. (15 to 25 centimeters; 6 to 10 inches thick)

Btn2--30 to 61 centimeters (12 to 24 inches); grayish brown (10YR 5/2) clay, very dark grayish brown (10YR 3/2) moist; strong fine and medium prismatic parting to moderate fine angular blocky structure; very hard, friable, very sticky and very plastic; common very fine roots mostly along ped faces; common very fine tubular pores; 5 percent cobbles and 5 percent gravel; common faint clay films on ped faces and lining pores; few faint silt coatings; cracks 5 to 12 millimeters wide and 20 to 30 centimeters apart; common pressure faces; ESP is 52; moderately alkaline (pH 8.0); clear wavy boundary. (25 to 38 centimeters; 10 to 15 inches thick)

Btn3--61 to 84 centimeters (24 to 33 inches); grayish brown and light brownish gray; (2.5Y 5/2 and 2.5Y 6/2) cobbly clay, dark grayish brown (10YR 4/2) with streaks of dark gray (10YR 4/1) moist; moderate coarse prismatic and moderate medium angular blocky structure; very hard, friable, very sticky and very plastic; common very fine roots mostly on the faces of prisms; 20 percent cobbles and 10 percent gravel; cracks 1 to 3 millimeters wide and 20 to 30 centimeters apart; common pressure faces; ESP is 52; moderately alkaline (pH 8.0); clear wavy boundary. (20 to 30 centimeters; 8 to 12 inches thick).

2Cn--84 to 117 centimeters (33 to 46 inches); pale yellow (2.5Y 7/4) and light yellowish brown (10YR 6/4) stony sandy loam, light olive brown (2.5Y 5/4) and brown (10YR 5/3) moist; massive; hard, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; 20 percent stones and 10 percent cobbles; ESP is 36; moderately alkaline (pH 8.0); gradual wavy boundary. (25 to 41 centimeters; 10 to 16 inches thick).

2C--117 to 152 centimeters (46 to 60 inches); pale yellow (2.5Y 7/4) extremely stony sandy loam, brown (10YR 5/3) moist; massive; hard, very friable, nonsticky and nonplastic; few very fine roots; few very fine tubular pores; ESP is 48; 30 percent stones, 40 percent cobbles and 15 percent gravel; moderately alkaline (pH 8.0).

TYPE LOCATION: Los Angeles County, California, San Clemente Island; about 2,500 feet going south from the intersection of Westshore road and road to Magazine area, going towards Eel Point, then 100 feet east to site; 32.9288 degrees latitude, -118.54393 degrees longitude; UTM zone 11, 3644451n, 355649e; U.S.G.S. Quad: San Clemente Island, central.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 18 degrees C. (64.5 degrees F.) The soil temperature is above 8 degrees C. (47 degrees F.) the entire year and the difference between the mean winter and the mean summer is less than 6 degrees C.
Soil moisture: moist in some or all parts between a depth of 18 to 33 centimeters (6 to 13 inches) from about December to about April and is dry the rest of the year.

Solum thickness: 75 to 100 centimeters (30 to 40 inches).
Sodium absorption ratio (SAR): 40 to 55 meq/L in the argillic horizon.
Exchangeable sodium percentage (ESP): 35 to 55 percent in the argillic horizon.
Electrical conductivity (EC): 5 to 10 ds/m in the upper part of the argillic and 10 to 16 in the lower part.
Reaction: neutral to moderately alkaline.

E horizon
Dry color: 10YR 5/3, 6/2, 6/3 or 7/2
Moist color: 10YR 3/2, 3/3, 4/2 or 4/3
Texture: cobbly/stony silt loam or cobbly/stony loam
Clay content: 15 to 20 percent
Rock fragments: 1 to 5 percent stones, 10 to 15 percent cobbles and 5 to 10 percent gravel.
Sodium absorption ratio: 8 to 12 meq/L
Electrical conductivity: 2 to 4 ds/m

Btn1 horizon, upper part
Dry color: 10YR 5/2, 5/3, 6/2 or 6/3.
Moist color: 10YR 3/2, 3/3, 4/2 or 4/3
Texture: clay
Clay content: 40 to 50 percent
Rock fragment content: 5 to 10 percent cobbles and 5 to 10 percent gravel.

Btn2 horizon, lower part
Dry color: 10YR 5/2, 5/3, 6/2, 6/3, 2.5Y 5/2 or 6/2
Moist color: 10YR 3/2, 3/3, 4/2, 4/3, 2.5YR 3/2 or 4/2
Texture: cobbly clay or cobbly silty clay
Clay content: 45 to 60 percent
Rock fragment content: 15 to 25 percent cobbles and 10 to 20 percent gravel.

C horizon
Dry color 10YR 5/3, 7/3, 7/4, or 2.5Y 7/4
Moist color is 10YR 4/3, 4/4, 2.5Y 4/4 or 5/4
Texture: cobbly or extremely stony sandy loam.
Rock fragment content: 25 to 30 percent stones, 30 to 35 percent cobbles and 5 to 15 percent gravel.
Sodium absorption ratio: 40 to 50 meq/L
Electrical conductivity: 10 to 16 ds/m

COMPETING SERIES:
Vizcapoint soils: are weathered from mostly sedimentary rocks and occur at San Nicolas Island marine terraces.

GEOGRAPHIC SETTING:
Landscape: islands
Landform: low lying marine terraces
Slope: 0 to 9 percent
Parent material: alluvium derived from mixed rock sources
Elevations: nearly sea level to 380 meters (0 to 1245 feet)
Climate: maritime with dry warm foggy summers and moist mild clear winters.
Mean annual precipitation: 235 millimeters (9 inches)
Mean annual air temperature: 17 degrees C. (62.5 degrees F.)
Frost-free season: 365 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Eelpoint soils: are moderately-deep to a lithic contact, have an SAR less than 13 and are on hills or terraces.
Lostpoint soils: have a paralithic contact and are on hills or terraces.
San Clemente soils: are moderately-deep to a lithic contact, SAR greater than 13 and are on hills or terraces.
Westshore soils: have a clayey-skeletal particle-size class and are on similar landforms.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; low or medium runoff; low saturated hydraulic conductivity.

USE AND VEGETATION: Eelcove soils are used mainly for military maneuvers and to a minor extent for wildlife habitat. The vegetation consists of cholla, Australian saltbush, boxthorn, goldentop and red brome.

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 from Eel Cove.

REMARKS:

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from a depth of 0 to 10 centimeters
Natric horizons - the zone from a depth of 10 to 84 centimeters
Lithologic discontinuity - at a depth of 84 centimeters

OSD revised during correlation of the San Clemente Island Interim Report in 2018.

Original classification from the 1982 Interim Report was - Fine, montmorillonitic, isothermic Typic Natrustalfs.

OSD revised during correlation of the San Clemente Island Interim Report in 2018.

ADDITIONAL DATA:

NASIS User Site/Pedon ID: 1982CA037EELCOVE
Classified using the Twelfth Edition Keys to Soil Taxonomy (2014)

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National Cooperative Soil Survey
U.S.A.