LOCATION FORBAR CAEstablished Series
TAXONOMIC CLASS: Mixed, mesic Typic Psammaquents
TYPICAL PEDON: Forbar fine sand - on a 0 percent slope under switch grass and saltgrass at 4,080 feet elevation. (When described on September 21, l979, the soil was dry throughout.)
A--0 to 2 inches; light brownish gray (2.5Y 6/2) fine sand, dark grayish brown (2.5Y 4/2) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine and fine roots; many very fine interstitial and common very fine tubular pores; slightly effervescent with disseminated lime; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 6 inches thick)
AC--2 to 7 inches; light brownish gray (2.5Y 6/2) fine sand, dark grayish brown (2.5Y 4/2) moist; common large prominent strong brown (7.5YR 5/6) mottles; single grain, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial pores; 8 percent pebbles; slightly effervescent with disseminated lime; mildly alkaline (pH 7.4); abrupt smooth boundary. (4 to 7 inches thick)
C1--7 to 31 inches; light yellowish brown (10YR 6/4) fine sand, dark yellowish brown (10YR 4/4) moist; many large distinct yellowish red (5YR 5/6) mottles; single grain, nonsticky and nonplastic; few very fine interstitial pores; slightly acid (pH 6.5); abrupt smooth boundary. (20 to 26 inches thick)
C2--31 to 43 inches; light yellowish brown (10YR 6/4) fine sand, dark yellowish brown (10YR 3/4) moist; common medium distinct yellowish red (5YR 4/6) mottles; single grain, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; neutral (pH 7.0); abrupt smooth boundary. (10 to 14 inches thick)
2C--43 to 50 inches; light gray (10YR 7/2) fine sand, dark grayish brown (10YR 4/2) moist; single grain, nonsticky and nonplastic; few very fine roots; common very fine interstitial pores; neutral (pH 7.0); abrupt smooth boundary. (4 to 9 inches thick)
2Cq--50 to 55 inches; very pale brown (10YR 7/3) fine sand, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine interstitial pores; 10 percent pebbles; neutral (pH 7.0); abrupt smooth boundary. (4 to 8 inches thick)
2C--55 to 60 inches; very pale brown (10YR 7/3) fine sand, brown (10YR 4/3) moist; single grain, nonsticky and nonplastic; few very fine interstitial pores; 14 percent pebbles; slightly effervescent with disseminated lime; moderately alkaline (pH 8.2).
TYPE LOCATION: Siskiyou County, California; 2,000 feet west of 1,400 feet north of the southeast corner of section 10, T.46 N., R.2 E.
RANGE IN CHARACTERISTICS: The depth of alluvium is 60 inches or more. The mean annual soil temperature ranges from 48 to 51 degrees F. Solum thickness ranges from 2 to 6 inches.
Carbonates are present in the A horizon and are always present but erratic with depth in the C horizon. Clay content ranges from 0 to 5 percent. Coarse and very coarse sands range from 10 to 20 percent throughout the profile.
The A horizon has dry color of 10YR 6/2, 6/3; or 2.5Y 6/2 and moist color of 10YR 4/2, or 2.5Y 4/2. Gravel range from 0 to 10 percent. Reaction is mildly or moderately alkaline.
The AC horizon has dry color of 10YR 6/2, 6/3, 7/2; 2.5Y 6/2 or 7/2 and moist color of 10YR 4/2, 4/3, 5/2; 2.5YR 4/2 or 5/2. Mottles of 10YR 5/6, 6/6 or 7.5YR 5/6 are always present. Gravel range from 0 to 10 percent.
The C horizon has dry color of 10YR 6/4, 7/2, 7/3 or 2.5Y 6/2 and moist color of 10YR 3/4, 4/2, 4/3 or 4/4. Gravel range from 0 to 15 percent. Reaction is slightly acid to moderately alkaline. Mottles are always present.
COMPETING SERIES: These are the Arlovol, Conrad, Gothenburg, Heceta, Junius, Stafford, Tryon, Tyre and Wanser series. Arloval soils have a solum thickness of 6 to 10 inches, commonly noncalcareous in the solum, and are either mildly or moderately alkaline throughout. Conrad soils have buried A horizons and dominantly have chromas of 1 in the textural control section. (See Remarks) Gothenburg soils contain an higher average percentage of coarse fragments and 25 percent or more very coarse and coarse sands in the textural control section. Heceta soils are non-calcareous throughout. Junius soils have a solum thickness that ranges from 20 to 40 inches, have B horizons and lack carbonates in the surface 20 inches. Stafford soil have a solum thickness that ranges from 20 to 40 inches and have B horizons. Tryon soils have a solum thickness of 3 to 9 inches, have buried A horizons, have an 0 horizons and are only calcareous in the O horizons. Tyre soils have a lithic contact at depth of 20 to 40 inches. Wanser soils have a mean annual soil temperature that ranges from 51 to 54 degrees F.
GEOGRAPHIC SETTING: The Forbar soils are in lake basins. Slopes are 0 to 2 percent. The soils formed in alluvium weathered from tuff and lacustrine sediment of volcanic ash. Elevation are 4,075 to 4,090 feet. The mean annual precipitation is about 12 to 16 inches. Snowfall is 15 to 25. The mean January temperature is about 30 degrees F; mean July temperature is 65 degrees F; mean annual temperature is about 46 to 50 degrees F. Frost-free season is about 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Capjac, Lamath and Tulana. These soils all have medial particle size control sections.
DRAINAGE AND PERMEABILITY: Very poorly drained; slow runoff; rapid permeability. A water table is at a depth of 6 to 18 inches from December to June unless artificially drained.
USE AND VEGETATION: This soil is used for wildlife habitat. Vegetation is switchgrass and saltgrass.
DISTRIBUTION AND EXTENT: North central California. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Siskiyou County, California, Butte Valley-Tule Lake Soil Survey. 1985.
REMARKS: Diagnostic horizons and features recognized in the pedon are:
Ochric epipedon - 0 to 12 inches (A, AC).
Control section -- The zone from 10 to 40 inches; sandy with about 4 percent clay.
Aquic moisture - A water table is at 6 to 18 inches unless artificially drained. Prominent mottles occur at a depth of 2 inches. Hue is 2.5Y and chromas are 2.
The Conrad series is of minor extent and currently being remapped. The present data collected indicates that the Conrad series will be classified as a Mollic Psammaquents, mixed, mesic.
Last revised by the state on 3/86.