LOCATION CARGENT CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Typic Dystroxerepts
TYPICAL PEDON: Cargent very gravelly sandy clay loam--on a south facing 71 percent slope under deerbrush, canyon liveoak, Oregon white oak, and grasses at an elevation of 2,500 feet. (Colors are for dry soil unless stated otherwise. When described on October 7, 1982 the upper 4 inches were slightly moist from recent rains. The soil was dry below).
The soil surface is partially covered by 60 percent pebbles.
Oi--1 to 0 inches; leaves and twigs.
A--0 to 3 inches; brown (7.5YR 5/4) very gravelly sandy clay loam, dark brown (7.5YR 3/4) moist; moderate fine and very fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common medium, fine, and very fine roots; common fine and very fine tubular pores; 40 percent pebbles; neutral (pH 7.0); clear wavy boundary. (3 to 5 inches thick).
Bt1--3 to 12 inches; light brown (7.5YR 6/4) very gravelly clay loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common medium, fine and very fine roots; few fine, common very fine tubular pores; few thin clay films lining pores and bridging mineral grains; 35 percent pebbles, 10 percent cobbles; slightly acid (pH 6.5); gradual wavy boundary. (8 to 10 inches thick).
Bt2--12 to 21 inches; light brown (7.5YR 6/4) very gravelly clay loam, brown (7.5YR 4/4) moist; strong medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium, common fine and very fine roots; few fine, common very fine tubular pores; common thin clay films lining pores and bridging mineral grains; 45 percent pebbles, 5 percent cobbles; slightly acid (pH 6.1); gradual wavy boundary. (8 to 10 inches thick).
Bt3--21 to 32 inches; light brown (7.5YR 6/4) extremely gravelly loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine, common very fine roots; few fine, common very fine tubular pores; few thin clay films lining pores and bridging mineral grains; 55 percent pebbles, 10 percent cobbles; slightly acid (pH 6.5); abrupt wavy boundary. (1 to 15 inches thick).
R--32 inches; fractured, platy mica schist.
TYPE LOCATION: Trinity County, California; about 3 1/2 miles southwest of Douglas City, California; take Highway 3 5.6 miles west of Douglas City, turn south on dirt road, ford creek, go 0.7 mile, take left fork, go 0.5 mile, pedon described uphill 500 feet; 2,250 feet west, and 1,300 feet south of the northeast corner of section 26, T.32 N., R.10 W. Hoosimbim Mtn. Quadrangle.
RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 20 to 40 inches. The profile is slightly acid to neutral throughout. The particle-size control section averages 35 to 50 percent coarse fragments mainly pebbles. It averages more than 15 percent mica minerals in the very fine sand fraction. The soil moisture control section is dry in all parts from about July to October 1. The soil temperature exceeds 41 degrees F from about March to December, and exceeds 47 degrees F from about April to November. The mean annual soil temperature is 59 to 64 degrees F.
The A horizon is 7.5YR 5/4, 10YR 4/4, or 5/4. Moist color is 7.5YR 3/4, 10YR 3/4, or 3/3.
The B horizon is 7.5YR 6/4, 4/6, 5/4, 6/6, 10YR 4/4, 5/3, or 7/4). Moist color is 7.5YR 4/4, 3/4, 4/6, 10YR 3/4, 4/3, or 4/4. It is very gravelly clay loam, extremely gravelly loam, or extremely gravelly clay loam. It contains 20 to 30 percent clay.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: The Cargent soils are on south and west facing mountain slopes of 50 to 90 percent. Elevation is 1,900 to 4,200, but mostly below 3,500 feet and on south or west facing slopes. These soils formed in colluvium over residuum weathered from mica schist. The climate is characterized by cool, moist winters and warm, dry summers. Mean annual precipitation is 40 to 60 inches. Snowfall ranges from 6 to 24 inches. Mean January temperature is about 39 degrees F. Mean July temperature is about 76 degrees F. Mean annual temperature is 57 to 62 degrees F. Frost-free period is 90 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Demogul and Vitzthum soils. The Demogul soils are more than 60 inches to bedrock and have mean annual soil temperatures of less than 59 degrees F. They occur on northerly mountain slopes. The Vitzthum soils are less than 20 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; very rapid runoff; moderate permeability.
USE AND VEGETATION: This soil is used for watershed and wildlife habitat. Native vegetation consists of chaparral oak, deerbrush, Oregon white oak, and annual grasses.
DISTRIBUTION AND EXTENT: The Cargent soil is inextensive and occurs in the Klamath Mountains of northern California.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Trinity County, California, Weaverville Area, 1990. Name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--the zone from the surface to 3 inches (A).
Cambic horizon--the zone from 3 to 32 inches (Bt1, Bt2, Bt3).
Particle-size control section--the zone from 10 to 32 inches (Bt1, Bt2, Bt3).
Lithic contact--the boundary at 32 inches.