LOCATION EXPRESS CA
Established Series
MEB/KP
06/2011
EXPRESS SERIES
The Express series consists of moderately deep, excessively drained soils that formed in materials weathered from dioritic igneous rock. Express soils are on side slopes interfluves and drainages of hills and mountains on islands. Slopes range from 2 to 75 percent. The mean annual precipitation is about 355 millimeters (14 inches) and the mean annual temperature is about 21 degrees C (69 degrees F).
TAXONOMIC CLASS: Coarse-loamy, mixed, active, thermic Typic Haploxerepts
TYPICAL PEDON: Express sandy loam, on a north facing 75 percent side slope of mountain interfluve, under a cover of sage, Lemonade bush, Laurel and grasses and at an elevation of 1446 feet(441 meters). (Colors are for dry soil unless otherwise noted).
A1--0 to 8 inches, (0 to 20 cm); light brownish gray (10YR 6/2) broken face sandy loam, very dark grayish brown (10YR 3/2) broken face moist; 7 percent clay; moderate medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine roots; many fine interstitial and many very fine interstitial pores; 5 percent rounded 2 to 75 millimeter quartz-diorite fragments; slightly acid, pH 6.3 by pH meter 1:1 water; gradual wavy boundary. (9 to 20 cm thick)
Bw1--8 to 20 inches, (20 to 52 cm); grayish brown (10YR 5/2) broken face loam, dark brown (10YR 3/3) broken face moist; 9 percent clay; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; few very fine roots; many fine interstitial and many very fine interstitial pores; patchy faint clay films on rock fragments and patchy faint clay films between sand grains; 5 percent rounded 2 to 75 millimeter quartz-diorite fragments; slightly acid, pH 6.4 by pH meter 1:1 water; abrupt wavy boundary. (21 to 32 cm thick)
Bw2--20 to 33 inches, (52 to 85 cm); light yellowish brown (10YR 6/4) broken face loamy sand, dark yellowish brown (10YR 4/4) broken face moist; 6 percent clay; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; many fine interstitial and many very fine interstitial pores; faint clay films on rock fragments; 10 percent rounded 2 to 75 millimeter quartz-diorite fragments; slightly acid, pH 6.5 by pH meter 1:1 water; gradual wavy boundary. (7 to 42 cm thick)
Cr--33 to 39 inches, (85 to 98 cm); weakly cemented, highly fractured (less than 10 cm apart) quartz-diorite porphyry.
TYPE LOCATION: Santa Catalina Island, Los Angeles County, CA, in the Channel Islands Soil Survey Area 33 degrees, 20 minutes, 49 seconds North latitude and 118 degrees, 23 minutes, 17 seconds West longitude, NAD83. - U.S.G.S Quad: Santa Catalina Island East.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 15 to 22 degrees C. (59 to 71 degrees F.) The soil moisture control section is dry in all parts from about mid-June to mid-November and is usually moist the rest of the time.
The A horizon dry color is 10YR 7/2, 6/2, 6/3, 6/4. Moist color is 10YR 5/2, 4/2, 4/3, 4/4.
Textures are loamy sand, sandy loam, gravely sandy loam, fine sandy loam.
Coarse fragments may be 0 to 20 percent small gravels.
The Bw1 (A2 when present) horizon dry color is 10YR 7/2, 6/2, 6/3, 6/4. Moist color is 10YR 5/2, 4/2, 4/3, 4/4.
Textures are sandy loam, gravely sandy loam, loam, gravely loam, gravely fine sandy loam.
Coarse fragments may be 0 to 25 percent small gravels.
The Bw2 (when present) horizon dry color is 10YR 7/2, 6/2, 6/3, 6/4. Moist color is 10YR 5/2, 4/2, 4/3, 4/4.
Textures are loamy sand, very gravely loamy sand, sandy loam, gravely sandy loam, very gravely sandy loam.
Coarse fragments may be 0 to 40 percent small gravels.
The Cr horizon ranges from soft (un-cemented) to rigid (very strongly cemented) quartz-diorite porphyry and diorite. This Cr contact can vary to fragmental, thus increasing profile depths below 100 cm.
COMPETING SERIES: These are the
Vista,
Crystalhill,
Oregongulch series. Vista soils are superactive and form from granite, Crystalhill soils are very deep to densic bedrock. Oregongulch soils are moderately deep to densic bedrock.
GEOGRAPHIC SETTING: Express soils formed in dioritic igneous rock. on complex side slopes of interfluves of hills and mountains on islands. Slopes range from 45 to 75 percent. Elevations are from sea level to 1550 feet (0 to 472 meters). The climate is characterized by warm, dry summers and cool, moist winters with potential fog common all year. The mean annual precipitation is 13 to 24 inches (330 to 660 mm), the mean annual temperature is 61 to 73 degrees F. (16 to 23 degrees C.), and the frost free season is 355 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These soils are
Oboship,
Bosun,
Nauti,
Flyer,
Loadline and
Marpol. Oboship soils are found on predominately north aspects under continuous stands of oak and chaparral. Bosun soils are skeletal and found on side slopes especially lower portions, Nauti soils are fine-loamy and have an argillic horizon. Flyer soils have an argillic horizon. Loadline soils are shallow and typically found on convex positions like crests of interfluves and side slopes. Marpol soils are fine textured. All these soils are found on hills and mountains of islands.
DRAINAGE AND PERMEABILITY: Excessively drained; high runoff, rapid permeability.
USE AND VEGETATION: Wildlife habitat, recreation and building site development. Vegetation is predominately Coastal Sage Scrub and Non-native Scrub, Maritime Cactus Scrub and Coastal Bluff Scrub, Island Chaparral.
DISTRIBUTION AND EXTENT: Santa Catalina Island, Los Angeles County, California. The soil is not extensive. MLRA 20.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES PROPOSED: Santa Catalina Island, Los Angeles County, California, 2006.
REMARKS: The series name is coined. Diagnostic horizons and features recognized in this pedon:
Ochric epipedon--The zone from the soil surface to a depth of about 8 inches (20 centimeters (A horizons).
Cambic endopedon--The zone below the ochric epipedon to a depth of about 40 inches (100 centimeters (A horizons).
National Cooperative Soil Survey
U.S.A.