LOCATION DEWMINE CA
Established Series
Rev. KEJ/DJE
01/2023
DEWMINE SERIES
The Dewmine series consists of shallow, well drained soils that formed in material weathered from ultramafic rocks. Dewmine soils are on mountains and have slopes of 15 to 65 percent. The mean annual precipitation is 40 inches and the mean annual temperature is 43 degrees F.
TAXONOMIC CLASS: Clayey-skeletal, magnesic, frigid Lithic Argixerolls
TYPICAL PEDON: Dewmine gravelly loam - on a west facing slope of 45 percent under a cover of grasses, mountain mahogany and scattered Jeffrey pine at 6,200 feet elevation. (Colors are for dry soil unless otherwise stated. When described on 10/1/80 the soil was dry to 5 inches and moist from 5 to 19 inches.)
Oi--0 inch to 1; duff of matted needles and leaves. (0 to 3 inches thick)
A--1 to 3 inches; very dark gray (10YR 3/1) gravelly loam, black (10YR 2/1) moist; moderate very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine interstitial pores; 20 percent pebbles; slightly acid (pH 6.5); abrupt smooth boundary. (1 to 4 inches thick)
BA--3 to 6 inches; dark gray (10YR 4/1) very gravelly clay loam, very dark gray (10YR 3/1) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; common fine interstitial and very fine tubular pores; 35 percent pebbles; neutral (pH 7.0); clear wavy boundary. (2 to 5 inches thick)
BAt--6 to 11 inches; dark grayish brown (10YR 4/2) very gravelly clay loam, very dark gray (10YR 3/1) moist; moderate medium subangular structure; hard, firm, sticky and plastic; common very fine, few fine, medium and coarse roots; common fine interstitial, common fine and very fine tubular pores; few thin and moderately thick clay films on ped faces and in pores; 35 percent pebbles; slightly alkaline (pH 7.8); clear wavy boundary. (3 to 7 inches thick)
Bt--11 to 20 inches; yellowish brown (10YR 5/4) very gravelly clay, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; very hard, very firm, sticky and very plastic; few very fine, fine, medium and coarse roots; few very fine and fine tubular pores; many moderately thick clay films on peds and in pores; 45 percent pebbles, 5 percent cobbles and stones; slightly alkaline (pH 7.8); clear irregular boundary. (4 to 10 inches thick)
R--20 inches; highly fractured serpentinitic rock.
TYPE LOCATION: Siskiyou County, California; Shasta-Trinity National forest; about 9 miles west of Weed on the NE1/4, SW1/4, NW1/4, section 33, T.42N., R.6W., on a road cut.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 6 to 19 inches thick. Depth to bedrock ranges from 10 to 20 inches. Rock fragments make up 25 to 50 percent of the control section, but average greater than 35 percent. The soil, from a depth of about 5 inches down to bedrock, is usually moist in some part for 160 to 180 days from October 15 to May 1. It is dry in all parts for 45 to 90 days from July 1 to September 30. The mean annual soil temperature is 39 to 47 degrees F.
The A horizon has color of 10YR 3/1, 4/1, 5/2, 5/3, or 2.5Y 5/2 and moist color of 10YR 2/1, 3/1, 3/2 or 2.5Y 2/2. It is loam or clay loam with 15 to 30 percent clay modified by 15 to 10 percent pebbles, stones or cobbles. It is slightly acid through mildly alkaline.
The Bt horizon has dry color of 10YR 4/2, 5/4, 3/3, 3/2, or 2.5Y 5/2 and moist color of 10YR 3/1, 3/2, 3/3 inclusive or 2.5Y 2/2. It is heavy clay loam or clay and averages 35 to 45 percent clay modified by 35 to 50 percent pebbles, stones, or cobbles. It is neutral or mildly alkaline.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Dewmine soils are on mountains and have slopes of 15 to 65 percent. These soils are formed in material weathered from ultramafic rocks. Rock outcrop ranges from 5 to 20 percent. Elevation ranges from 5,000 to 6,500 feet. The climate has warm, dry summers and cool moist winters. The annual precipitation is 30 to 45 inches. The snow fall is 10 to 20 inches. The mean January temperature is 28 degrees F. and the mean July temperature is 63 degrees F. The mean annual temperature ranges from 38 to 45 degrees F. The frost-free season is 80 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: See Remarks.
DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for wildlife habitat, watershed, and limited grazing. The principal native plants are perennial bunchgrass, mountain mahogany, and a few scattered Jeffrey pine.
DISTRIBUTION AND EXTENT: Klamath Mountains of California and possibly southern Oregon. The soils of this series are not extensive. Their total acreage is about 9,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Siskiyou County. California, Shasta-Trinity and Klamath National Forests, 1983.
REMARKS: This series was established to map a new family in a survey area that mapped and classified map unit components only to the family level.
ADDITIONAL DATA: Particle-size of the argillic horizon (BAt and Bt) determined by hydrometer at Shasta-Trinity National Forest Lab. Base saturation of mollic epipedon by Hach Kit.
OSED scanned by SSQA. Last revised by state on 5/83.
National Cooperative Soil Survey
U.S.A.