LOCATION DANN CAEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, ferritic, mesic Typic Haploxerepts
TYPICAL PEDON: Dann very cobbly clay loam - on a west facing convex slope of 10 percent under sugar pine, ponderosa pine and manzanita, at 4030 feet elevation. (Colors are for dry soil unless otherwise stated. When described on May 22, 1980 the soil was moist below 10 inches).
A--0 to 5 inches; reddish brown (2.5YR 4/4) very cobbly clay loam, dusky red (10R 3/3) moist; strong very fine and fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, and common medium roots; many very fine interstitial pores; 5 percent pebbles (2-75mm), 30 percent cobbles (7.5-25cm) and 10 percent stones (25-40cm); slightly acid (pH 6.4); abrupt wavy boundary. (3 to 6 inches thick)
Bw1--5 to 21 inches; strong brown (7.5YR 5/6) extremely stony clay loam, dark brown (7.5YR 4/4) moist; weak very fine granular structure; soft, very friable, sticky and slightly plastic; many very fine and fine and common medium roots; many fine interstitial pores; 5 percent pebbles (2-75mm), 15 percent cobbles (7.5-25cm) and 50 percent stones (25-65cm); neutral (pH 6.8); clear irregular boundary. (10 to 21 inches thick)
Bw2--21 to 31 inches; strong brown (7.5YR 5/6) extremely stony clay loam; dark brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, sticky and slightly plastic; common fine and medium roots; common very fine interstitial pores; 10 percent greenish gray (5GY 6/1) saprolite with black (N 2/0) and strong brown (7.5YR 5/8) stains along fractures; 5 percent pebbles (2-75mm), 15 percent cobbles (7.5-25cm) and 50 percent stones (25-65cm); neutral (pH 7.0); abrupt irregular boundary. (7 to 14 inches thick)
R--31 to 60 inches; variegated reddish yellow (7.5YR 7/8) and greenish gray (5GY 6/1) hard, fractured, slightly weathered peridotite; many black (N 2/0) stains within fractures that are 1 to 2mm and 3 to 10cm apart.
TYPE LOCATION: Mendocino County, California; from U.S. Hwy 101 frontage road south of Reynolds, turn on Red Mountain access road and head about 4.5 miles to Cat Track road, head 5.5 miles to quarry, 10 feet west of road; 2150 feet south and 1800 feet west of the northeast corner of sec. 19, T.24N., R.16W.,MDBM, Leggett quadrangle.
RANGE IN CHARACTERISTICS: Depth to a lithic contact and thickness of the solum ranges from 20 to 40 inches. The mean annual soil temperature ranges from 53 to 57 degrees F. The soil between a depth of 10 and 35 inches or to a lithic contact, whichever is shallower, is moist in all parts from November 1 to June 1 and is dry in all parts from July 15 to October 1 in most years. Base saturation (sum) ranges from 50 to 75 percent throughout the profile. 25 to 40 percent of the soil surface is covered with cobbles and 5 to 15 percent is covered with stones. The particle-size control section averages 35 to 40 percent clay. Reaction is slightly acid or neutral throughout the profile.
The A horizon is 2.5YR 4/4, 5/4 or 5YR 5/4. Moist color is 10R 3/3, 3/4; 2.5YR 3/4 or 3/6. Clay content ranges from 27 to 35 percent. Gravel content is 2 to 10 percent, cobble content is 25 to 35 percent, and stone content is 5 to 15 percent. Total rock fragment content is 35 to 60 percent.
The Bw horizon is 7.5YR 4/6, 5/4, 5/6, 6/6 or 5YR 5/4. Moist color is 7.5YR 4/4, 4/6; 5YR 4/4, 4/6; 2.5Y 3/4 or 3/6. It is very stony clay loam, extremely stony clay loam or very stony clay with 35 to 50 percent clay. Total rock fragment content is 35 to 70 percent. Gravel content is 2 to 10 percent, cobble content is 15 to 45 percent, and stone content is 25 to 60 percent.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Dann soils are on mountains. Slopes are 5 to 75 percent. Elevations are 2000 to 4100 feet. Dann soils formed in material weathered from ultramafic intrusive rocks. The climate is characterized by hot dry summers and cool moist winters. Mean annual precipitation is 60 to 70 inches with occasional snowfall. Mean January temperature is about 45 degrees F.; mean July temperature is about 66 degrees F.; and the mean annual temperature is about 55 degrees F. The frost-free period is 150 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Casabonne, Hiltabidel, Hollowtree, Holohan, and Littlered soils. Casabonne, Hollowtree and Holohan soils formed from sandstone. They occur on the mountains surrounding the ultramafic rock intrusion on which Dann, Hiltabidel and Littlered soils formed. Hiltabidel and Holohan soils are greater than 40 inches deep to a lithic contact. Casabonne soils are greater than 40 inches deep to a paralithic contact. Littlered soils are less than 20 inches deep to a lithic contact. Hollowtree soils have an argillic horizon and have mixed mineralogy.
DRAINAGE AND PERMEABILITY: Well drained; surface runoff under bare soil conditions is medium through very rapid; moderately slow permeability.
USE AND VEGETATION: This soil is used for wildlife habitat and watershed. Vegetation consists of sugar pine, ponderosa pine, incense cedar, Jeffrey pine, manzanita, bracken fern, buckwheat, silene spp. and stonecrop. Chemical characteristics, including a low calcium to magnesium ratio restrict plant growth and influence species composition.
DISTRIBUTION AND EXTENT: Mendocino County, California, Red Mountain area. This series is not extensive. MLRA 5.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, Western Part, California, 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon -- the zone from 0 to 5 inches (A)
Cambic horizon -- the zone from 5 to 31 inches (Bw1, Bw2)
Lithic contact -- the boundary at 31 inches (R).
Mineralogy -- oxidic. Dithionite citrate extractable iron: Bw1 = 30.4 percent; Bw2 = 19.0 percent
ADDITIONAL DATA: NSSL samples: 817284, 817285, 821748-821750