LOCATION CRISPIN CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, isomesic Ultic Haplustalfs
TYPICAL PEDON: Crispin loam - on a southwest facing slope of 3 percent under annual grasses and forbs at 120 feet elevation. (Colors are for dry soil unless otherwise stated. When described on October 30, 1986 the soil was slightly moist throughout.
A--0 to 6 inches; dark brown (10YR 3/3) loam, very dark brown (10YR 2/2) moist; strong very fine, fine and medium granular structure; hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular and interstitial pores; 5 percent hard subrounded sandstone pebbles (2-20mm); moderately acid (pH 5.8); clear wavy boundary. (5 to 10 inches thick)
AB--6 to 14 inches; dark brown (10YR 3/3) loam, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; hard, friable, sticky and plastic; common very fine and fine roots; many very fine tubular and interstitial pores; 5 percent hard subrounded sandstone pebbles (2-20mm); strongly acid (pH 5.4); clear wavy boundary. (5 to 10 inches thick)
Bt--14 to 23 inches; brown (10YR 4/3) loam, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; hard, friable, sticky and plastic; common very fine and fine roots; many very fine tubular and interstitial pores; few thin clay films lining pores and bridging mineral grains; 5 percent hard subrounded sandstone pebbles (2-20mm); moderately acid (pH 5.8); abrupt irregular boundary. (8 to 27 inches thick)
2Cr--23 to 62 inches; variegated yellowish brown (10YR 5/6) and yellow (10YR 7/6) weakly consolidated marine sediments, strong brown (7.5YR 4/6) and yellowish brown (10YR 5/6) moist; massive; very hard, very firm, few very fine roots; 15 percent hard subrounded and subangular pebbles (2-75mm); very strongly acid (pH 4.8)
TYPE LOCATION: Mendocino County, California; about 300 feet west and 625 feet north of the southeast corner of sec. 13, T.13N., R.17W., MDBM, Point Arena quadrangle.
RANGE IN CHARACTERISTICS: Depth to soft bedrock is 20 to 40 inches. The umbric epipedon is 20 to 40 inches thick and contains 2.0 to 5.0 percent organic carbon. The mean annual soil temperature ranges from 50 to 56 degrees F. The difference between mean summer and mean winter soil temperature ranges from 6 to 9 degrees F. The soil between the depths of 6 and 18 inches is moist in all parts from November 1 to June 1. It is dry in some or all part from July 1 to October 1 in most years.
The A horizon is 10YR 3/2, 3/3, 4/2 or 4/3. Moist color is 10YR 2/2 or 3/2. Clay content ranges from 15 to 20 percent. Gravel content ranges from 0 to 5 percent. Base saturation (ammonium acetate) ranges from 35 to 50 percent. Reaction is strongly or moderately acid.
The Bt horizon is 10YR 3/2, 3/3, 4/2 or 4/3. Moist color is 10YR 2/2, 3/2 or 3/3. Clay content ranges from 23 to 27 percent. Gravel content ranges from 0 to 5 percent. Base saturation (sum of cations) ranges from 50 to 70 percent.
The 2Cr horizon is weakly consolidated marine sediments. Color is7.5YR 4/6, 5/6; 10YR 5/6, 6/6 or 7/6. Moist color is 7.5YR 4/4, 4/6; 10YR 5/4, 5/6. Gravel content ranges from 15 to 30 percent.
COMPETING SERIES: These are the Cabrillo (CA), Inverness (CA), Ornbaun (CA) and Zeni (CA) soils. Cabrillo soils are very deep. Inverness soils have a paralithic contact between 40 and 60 inches and contain 5 to 20 percent mica flakes. Ornbaun soils have a paralithic contact between 40 and 60 inches. Zeni soils do not have coarse fragments in the paralithic and do not have umbric epipedons.
GEOGRAPHIC SETTING: The Crispin soils occur on marine terraces. Slopes are 0 to 5 percent. Elevations are 20 to 240 feet. The soil formed in alluvium from mixed rock sources. The climate is humid with cool foggy summers and cool moist winters. A strong marine influence limits the diurnal and annual range of temperature. Mean annual precipitation ranges from 35 to 45 inches. Mean January temperature is about 48 degrees F., mean July temperature is about 57 degrees F., and the mean annual temperature is 53 degrees F. The frost-free period is 250 to 330 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the competing Cabrillo, and the Biaggi, Flumeville, Mallopass and Windyhollow soils. These soils are on similar landscape positions. Biaggi soils are moderately deep to a lithic contact. Flumeville and Windyhollow soils are often in subtle depressions. Flumeville soils have mottles between 10 and 30 inches, and have a fine particle-size control section and a mollic epipedon. Windyhollow soils have mottles between 30 and 50 inches, and have a mollic epipedon. Mallopass soils have mottles between 50 and 60 inches, and have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; surface runoff under bare soil conditions is very slow or slow; moderate permeability in the solum and slow permeability below.
USE AND VEGETATION: This soil is used for livestock grazing and as wildlife habitat. A few areas are used as pasture and for hay production. Vegetation consists of perennial and annual grasses and forbs.
DISTRIBUTION AND EXTENT: Northern coastal California. The series is not extensive. MLRA 4.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, California, Western Part, 1993.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - the zone from 0 to 23 inches (A, AB, Bt)
Argillic horizon (minimal) - the zone from 14 to 23 inches (Bt)
Paralithic contact - the boundary at 23 inches. The horizon is massive and very hard - it does not slake in water. Can be dug with difficulty with backhoe or sharp shooter. Cementing agent unknown.
Many areas now mapped as the Crispin series were mapped as Kneeland, Hardpan variant in the Soil Survey of the Mendocino County Bottomlands California, 1973.