LOCATION PLASKETT CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Lithic Haploxerolls
TYPICAL PEDON: Plaskett gravelly loam - under mixed hardwoods. (Colors are for dry soil unless otherwise stated.)
01--1 to 0 inches; litter of oak leaves and twigs in various stages of decomposition; moderately acid (pH 5.9); abrupt wavy boundary. (0 to 3 inches thick)
A11--0 to 3 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; soft, very friable, nonsticky, nonplastic; many very fine roots; many very fine interstitial pores; about 30 percent angular shale fragments; moderately acid (pH 6.0); clear wavy boundary. (2 to 9 inches thick)
A12--3 to 10 inches; dark brown (10YR 4/3) very shaly loam, dark brown (10YR 3/3) moist; weak medium granular structure; soft, very friable, nonsticky, nonplastic; many very fine, common medium roots; many very fine and common fine interstitial pores; 75 percent shale fragments; slightly acid (pH 6.4); clear wavy boundary. (0 to 12 inches thick)
R--10 to 24 inches; pale brown (10YR 6/3) fractured hard fine grained sandstone; brown (10YR 4/3) moist; slightly acid (pH 6.5); brown soil similar to that in the horizon above occurs in rock fractures. Roots extend into the fractured rock.
TYPE LOCATION: Monterey County, California; Hunter Liggett Military Reservation about 1/4 mile east and 100 feet north of SW corner of sec. 20, T.23S., R.6E.
RANGE IN CHARACTERISTICS: Depth to lithic contact of hard but fractured rock ranges from 6 to 20 inches. Dominantly, the soils are more than 10 inches deep. The mean annual soil temperature at the lithic contact ranges from 55 degrees to 58 degrees F. The soil below the upper few inches usually is continuously moist from some time in October or November until some time in May and is dry all the rest of the time. Pebbles, cobblestones, and larger stones make up 35 to 75 percent of the volume. Base saturation is more than 75 percent throughout. Organic matter is between 1 and 4 percent.
The A horizon when dry is dark gray, dark grayish brown, dark brown or grayish brown (10YR 4/1, 4/2, 4/3, 5/2; 2.5Y 5/2). When moist, it is very dark grayish brown, very dark brown or dark brown (10YR 3/2, 2/2, 3/3; 2.5Y 3/2; 7.5YR 3/2). This horizon is sandy loam or loam with less than 18 percent clay and is modified by gravel, cobblestones, stone, and angular shale fragments. It is neutral to moderately acid.
In pedons having B horizons or C horizons above the bedrock, the color, texture, and reaction are similar to the A horizon. Some pedons have a few thin clay films accompanied by little or no clay increase.
COMPETING SERIES: These are the Bakeoven, Gamboa, Godde, Hambright, Lickskillet, Lopez, McMullin, Permanente, Rockly, Venator, and Virgin Peak soils. Bakeoven, Lickskillet, and Rockly soils have more than 18 percent clay and a mean annual soil temperature of 47 degrees to 54 degrees F. Godde and Virgin Peak soils have an aridic moisture regime that borders on xeric. Gamboa soils have a lithic contact below 40 inches. Hambright and Lopez soils have thermic temperature. McMullin soils have less than 35 percent rock fragments. Permanente soils are mildly alkaline and have dry hue of 7.5YR or redder. Venator soils have a mean annual soil temperature of 47 degrees to 49 degrees F.
GEOGRAPHIC SETTING: Plaskett soils are on steep and very steep side slopes at elevations of 1,800 to 4,200 feet. They formed in residuum from fractured, slightly weathered sandstone, shale, and schist. The climate is dry subhumid mesothermal with a mean annual rainfall of 30 to 70 inches with warm dry summers and cool moist winters. The average January temperature is about 40 degrees F., average July temperature is about 66 degrees F., and the mean annual temperature is about 54 degrees F. Freeze-free season is 180 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gaviota and Reliz soils and the competing Gamboa and McMullin soils. Gaviota and Reliz soils have ochric epipedons.
DRAINAGE AND PERMEABILITY: Excessively drained; rapid or very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used principally for watershed, wildlife, and recreation. Vegetation is mainly hardwoods and brush species such as Canyon live oak, laurel, scrub interior live oak, and poison oak together with scattered coulter and ponderosa pine.
DISTRIBUTION AND EXTENT: Santa Lucia range in the central part of the Coast Range in California. The soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Monterey County, California, 1972.
REMARKS: The Plaskett soils would formerly have been classified as Lithosols.
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
OSED scanned by SSQA. Last revised by state on 11/72.