LOCATION KAROC CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, nonacid, mesic Xeric Torriorthents
TYPICAL PEDON: Karoc very gravelly sandy loam--on a 59 percent east facing slope under bluebunch wheatgrass, thurber needlegrass and rabbitbrush at 4200 feet elevation. (When described on June 28, 1979, the soil was dry throughout.)
A--0 to 3 inches; dark grayish brown (10YR 4/2) very gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and few fine roots; common very fine interstitial pores; 45 percent pebbles, 10 percent cobbles, 2 percent stones; neutral (pH 7.0); clear smooth boundary. (3 to 5 inches thick)
C1--3 to 13 inches; pale brown (10YR 6/3) very gravelly sandy loam, dark brown (10YR 3/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine and few fine roots; few very fine interstitial and common very fine tubular pores; 45 percent pebbles, 10 percent cobbles, 1 percent stones; neutral (pH 7.0); clear smooth boundary. (9 to 25 inches thick)
C2--13 to 60 inches; pale brown (10YR 6/3) very gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; massive; soft, very friable, nonsticky and nonplastic, common very fine and few fine roots; common very fine interstitial pores; 45 percent pebbles, 10 percent cobbles, 1 percent stones; neutral (pH 7.0).
TYPE LOCATION: Siskiyou County, California; about 3.5 miles northwest of Captain Jacks Stronghold, 475 feet north, 2,050 feet west of the southeast corner of section 6, T.46 N., R.4 W.
RANGE IN CHARACTERISTICS: The depth of colluvial material is 60 inches or more. The mean annual soil temperature ranges from 48 degrees F. to 52 degrees F. The soil temperature at a depth of 20 inches is above 41 degrees F. from about March 15 to December 1 (255 days) and is above 47 degrees F. from about April 15 to November 15 (210 days). The soil between depths of 12 and 36 inches is dry in all parts from June 20 until November 10 (140 days). The soil moisture control section is dry more than half the time the soil temperature is above 41 degrees F. Rock fragments range from 35 to 60 percent. Stones and cobbles range from 5 to 15 percent. Gravel range from 30 to 45 percent. Clay content ranges from 10 to 18 percent. Reaction is neutral or mildly alkaline.
The A horizon has dry color of 10YR 4/2, 5/2 or 6/3 and moist color of 10YR 3/2 or 3/3.
The C horizon has dry color of 10YR 6/2, 6/3, 6/4 or 7.5YR 5/4 and moist color of 10YR 3/3, 3/4, 4/3 or 7.5YR 4/4.
COMPETING SERIES: The is the Wiskiflat (T) series. The Wiskiflat series has a mean annual soil temperature of 55 to 59 degrees F. and the clay content in the control section averages 5 to 10 percent and is moist 10 to 20 days between July and October due to convection storms.
GEOGRAPHIC SETTING: Karoc soils are on colluvial side slopes. Slopes are 50 to 75 percent. The soils formed in colluvium weathered from tuff and andesite. Elevations are 4100 to 4800 feet. The climate is semiarid with warm dry summers and cool moist winters. The average annual precipitation is about 10 to 12 inches. Snowfall is 15 to 25 inches. The mean annual temperature is about 46 to 50 degrees F. The mean January temperature is about 28 to 31 degrees F. and the mean July temperature is about 64 to 66 degrees F. Frost-free season is about 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bucklake (T), Demox (T), Dunnlake and Rangee (T) soils. Bucklake soils are moderately deep to bedrock, have a mollic epipedon and a fine particle control section. Demox soils have a mollic epipedon that ranges from 22 to 36 inches thick. Dunnlake soils have a mollic epipedon, a fine particle control section and are shallow to bedrock. Rangee soils are moderately deep to a hardpan, have a mollic epipedon and a very-fine particle control section.
DRAINAGE AND PERMEABILITY: Well drained; very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Karoc soils are used for wildlife habitat and as rangeland. Vegetation is bluebunch wheatgrass, thurber needlegrass and rabbitbrush.
DISTRIBUTION AND EXTENT: North central California. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Siskiyou County, California; Butte Valley-Tule Lake Soil Survey, 1985.
REMARKS: Diagnostic horizons and features recognized in the pedon are:
Ochric epipedon--0 to 3 inches (A,C) ranges from 0 to 60 inches.
Control section--The zone from 10 to 40 inches, loamy-skeletal family - very gravelly sand loam with about 15 percent clay and 56 percent rock fragments.
Aridic moisture--Dry 140 days. Above 41 degrees F. 255 days. Dry greater than half the time the soil temperature is greater than 41 degrees F.
Last revised by the state on 2/86.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.