LOCATION ELAM                    CA

Established Series
Rev. KDG/JEM/ET
12/2022

ELAM SERIES

The Elam series consists of somewhat excessively drained Regosols (See Remarks) developed from moderately coarse textured alluvium from rhyolitic and andesitic rocks. They occur on gently sloping fans under coniferous vegetation. Characteristically, the Elam soils have thin grayish brown A horizons which grade into light gray or paler parent materials. The soils are deep, gravelly or very gravelly, and medium acid throughout. The Elam series occurs in the upper valleys of the Cascade Mountains in California and is used almost exclusively for timber production.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, nonacid, frigid Typic Xerofluvents

TYPICAL PEDON: Elam gravelly sandy loam (on a southwest facing slope of 10 percent at an elevation of 4,800 feet under ponderosa pine, white fir, sugar pine, prostrate ceanothus, and white thorn ceanothus vegetation in an area used for timber production).

Oi & Oe--2 to 0 inches; fresh needles and leaves becoming more decomposed with depth; abrupt, smooth, lower boundary, 1/2 to 3 inches thick.

A11--0 to 2 inches; dark gray (10YR 4/1) gravelly sandy loam, black (10YR 2/1) when moist; strong fine granular structure; soft when dry, very friable when moist; abundant very fine roots; many very fine pores; strongly acid, pH 5.2; abrupt smooth lower boundary. (1/2 to 3 inches thick)

A12--2 to 5 inches; light brownish gray (2.5Y 6/2) very gravelly sandy loam, dark grayish brown (2.5Y 4/2) when moist; strong fine granular structure; soft when dry, very friable when moist, abundant very fine roots; many very fine pores; moderately acid, pH 5.6; gradual smooth lower boundary. (1/2 to 3 inches thick)

C1--5 to 20 inches; light gray (10YR 7/2) very gravelly sandy loam, light brownish gray (10YR 6/2) when moist; strong fine granular structure; soft when dry, very friable when moist; plentiful very fine and fine roots; many very fine pores, moderately acid, pH 5.7; diffuse lower boundary. (10 to 15 inches thick)

C2--20 to 60 inches+; light gray (10YR 7/2) very gravelly sandy loam, light brownish gray (10YR 6/2) when moist; nearly single grain; nearly loose when dry and moist; few large roots, common fine pores; moderately acid, pH 5.7 increasing to 6.0.

TYPE LOCATION: SW corner of the SE1/4 of the SE1/4 of section 31, T. 29 N., R. 5 E., 2 miles NW of Gurnsey Creek camp ground, just east of California Highway No. 36, at the eastern edge of Tehama County, California.

RANGE IN CHARACTERISTICS: The A11 horizon varies in color from grayish brown to very dark grayish brown or dark gray. The lower horizons are generally light gray but may be very pale brown or white. The surface texture varies from gravelly sandy or fine sandy loam to gravelly loamy sand. The C horizon is very gravelly sandy loam or very gravelly loam. The soil reaction is about medium acid throughout although the pH tends to increase slightly with depth.

COMPETING SERIES:

GEOGRAPHIC SETTING: Nearly level to gently sloping. Soil is associated with short alluvial fans. The Elam soils occur at elevations of 4,000 to 5,000 feet in a humid mesothermal but nearly microthermal climate, having a mean annual precipitation of 50 to 55 inches, with cool, nearly dry summers and cold, wet winters. Snow covers much of the area from November until March. The average January temperature is 30 degrees F., the average July temperature is 62 degrees F., with a mean annual temperature of 45 degrees F., and an average frost-free season of 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: The Elam soils occur in the same general areas the Childs, Chummy, Jiggs, and Lyonsville soils. They resemble the Delaney, Jiggs, and Lyonsville soils in some respects. However, the Delaney soils developed in alluvium from andesite which is usually tuffaceous. The Jiggs soils developed in rhyolite and are shallow or moderately deep. The Lyonsville soils developed in dacite and have weakly developed textural B horizons.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; runoff is slow because of the rapid permeability. High water tables may occur seasonally along the edges of wet meadows if the soil is underlain by slowly or less permeable rock strata.

USE AND VEGETATION: Used almost exclusively for timber production. Cleared areas support little or no grass. Some areas are mined for gravel. Ponderosa pine, white fir, sugar pine, Jeffery pine, with an understory of prostrate ceanothus and white thorn ceanothus. Lodgepole pine and Jeffery pine occur in areas of high water tables.

DISTRIBUTION AND EXTENT: Along the edges of small valleys at higher elevations in the southern Cascade Mountains of California.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Soil survey of Tehama County, California. Source of name is from Elam Creek, Eastern Tehama County, California.

REMARKS: The soil is classified as follows:

USDA Yearbook: Alluvial soil.
Revised Classification: 1.430, Regosol (usually moist)
University of California, Storie and Weir: Podzolic
Alluvial, Profile Group 1.

The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET

OSED scanned by SSQA. Last revised by state on 10/59.

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National Cooperative Soil Survey
U.S.A.