LOCATION STONEGOLD               CA

Established Series
Rev: LJL/PBF/ET
12/2015

STONEGOLD SERIES

The Stonegold series consists of very shallow and shallow well drained soils that formed in residuum and colluvium from basalt and other volcanic sources. Stonegold soils are on summits of basalt hills and mountains. Slope ranges from 2 to 8 percent. The mean annual precipitation is about 5 inches and the mean annual air temperature is about 64 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, thermic Lithic Haplargids

TYPICAL PEDON: On Stonegold extremely cobbly loam, 2 to 8 percent slopes at an elevation of 3,949 feet. (Colors are for dry soil unless otherwise noted.) The surface is covered by approximately 50 percent gravel, 25 percent cobbles and 10 percent stones.

A -- 0 to 3 inches; very pale brown (10YR 7/3) extremely cobbly loam, dark yellowish brown (10YR 4/4) moist; moderate thick platy structure parting to weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common fine and medium tubular pores; 50 percent gravel, 25 percent cobbles, and 10 percent stones; strongly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (2 to 4 inches thick)

Btk -- 3 to 11 inches; light brown (7.5YR 6/4) gravelly loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; common very fine, fine, and medium roots; few fine tubular pores; many faint discontinuous clay films on faces of peds; 15 percent gravel, 5 percent cobbles, and trace of stones; very few fine carbonate threads and soft masses; slightly effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary. (4 to 14 inches thick)

R -- 11 to 14 inches; hard, slightly fractured basalt bedrock with some soil, roots, and lime and silica cementation in fractures.

TYPE LOCATION: San Bernardino County, California; about 750 feet east and 30 feet south of the northwest corner of section 14 , T. 14 N., R. 1 E., 35 degrees, 18 minutes, 58 seconds north latitude and 116 degrees, 51 minutes, 05 seconds west longitude; East of Goldstone 7.5 minute quadrangle; (UTM 11S, 0513521e 3807908n)

RANGE IN CHARACTERISTICS:

Soil moisture control section: Usually dry, moist in some part for short periods during winter and early spring and for 10 to 20 days cumulative between July and October following convection storms. The soils have a Typic-Aridic moisture regime.

Soil temperature: 63 to 68 degrees F.
Organic matter: 0 to 0.5 percent
Surface rock fragments: 40 to 60 percent gravel, 15 to 40 percent cobbles and 0 to 15 percent stones.


Control section -

Depth to bedrock: 8 to 18 inches

Clay content: 15 to 25 percent

Rock fragments: 5 to 20 percent, mainly gravel


A horizon

Value: 5 to 7 dry, and 4 or 5 moist

Chroma: 3 or 4, dry or moist

Texture of the fine earth: sandy loam or loam

Clay content: 10 to 15 percent

Rock fragments: 35 to 60 percent gravel, 15 to 35
percent cobbles, and 0 to 15 percent stones; range is
from 50 to 85 percent

Consistence: soft or slightly hard, very friable or
friable

Effervescence: very slightly to strongly effervescent

Reaction: slightly or moderately alkaline


Btk horizon

Hue: 7.5YR or 10 YR

Value: 5 to 7 dry, and 4 or 5 moist

Chroma: 3 or 4, dry or moist

Consistence: slightly hard to hard, very friable to firm

Effervescence: very slightly to strongly effervescent

Reaction: slightly or moderately alkaline

Calcium carbonate equivalent: 0 to 5 percent

COMPETING SERIES: These are the Aftaden (NM), Sparkhule (CA), and Zyplar T (NV) series. Aftaden and Zyplar soils receive more rainfall and are moist for more than 20 days cumulative in some part of the soil moisture control section during July and October. In addition, Zyplar soils have characteristically lower soil temperatures, and have 20 to 30 percent clay in the control section. Sparkhule soils have finer textures and redder hues in the control section.

GEOGRAPHIC SETTING: Stonegold soils are on summits of basalt hills and mountains. Slope ranges from 2 to 8 percent. The soils formed in residuum and colluvium from basalt and other volcanic sources. Elevations are from 3,200 to 4,500 feet. The climate is arid with hot, dry summers and warm, moist winters. Most precipitation occurs in winter but a significant portion is received between July and September following convection storms. The mean annual precipitation is 4 to 7 inches; mean annual air temperature is 61 to 66 degrees F., and the frost-free season is 240 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Haleburu soils on adjacent side slopes. Haleburu soils do not have a argillic horizon, have a duripan over bedrock and loamy-skeletal control sections.

DRAINAGE AND PERMEABILITY: Well drained; very to high runoff; moderate permeability.

USE AND VEGETATION: Stonegold soils are used for military exercises and wildlife habitat. The present vegetation is mainly creosotebush and shadscale with lesser amounts of Nevada ephedra, turpentine broom, range ratany, white bursage, and Joshua tree.

DISTRIBUTION AND EXTENT: Mojave Desert of southeastern California. These soils are of small extent in MLRA 30.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: San Bernardino County, California, Fort Irwin Soil Survey Area, 2000. The name is coined.

REMARKS: Diagnostic horizons and features recognized in the profile are:

1. Ochric epipedon -- 0 to 3 inches (A horizon)
2. Argillic horizon -- 3 to 11 inches (Btk horizon)
3. Lithic contact -- the zone beginning at 11 inches (R
horizon)
4. Particle-size control section -- 3 to 11 inches (Btk
horizon)

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 6/2000. ET

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National Cooperative Soil Survey
U.S.A.