LOCATION PAINTROCKS CA

Established Series
Rev: PBF/ET
12/2015

PAINTROCKS SERIES

The Paintrocks series consists of very shallow, excessively drained soils formed in granitic residuum. The Paintrocks soils are on mountains, hills, and pediments. Slope ranges from 2 to 50 percent. The mean annual precipitation is about 5 inches and the mean annual air temperature is about 64 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, calcareous, thermic Lithic Torriorthents

TYPICAL PEDON: On Rock outcrop-Paintrocks complex, 15 to 50 percent slopes at an elevation of 3,457 feet. (Colors are for dry soil unless otherwise noted.)

The soil surface is partially covered with 40 percent gravel, 5 percent cobbles, and 5 percent stones.

A -- 0 to 2 inches; pale brown (10YR 6/3) very gravelly coarse sandy loam, brown (10YR 4/3) moist; weak thin platy structure; soft, very friable, slightly sticky and slightly plastic; slightly effervescent; 35 percent gravel, 2 percent cobbles, and trace of strones; neutral (pH 7.0); abrupt smooth boundary. (1 to 3 inches thick)

Cr -- 2 to 3 inches; partially to moderately weathered granitic bedrock material of moderate to high excavation difficulty.

R -- 3 inches; unweathered, fractured granitic bedrock with pockets of weathered bedrock material of moderate to high excavation difficulty.

TYPE LOCATION: San Bernardino County, California; about 2 miles WNW of Painted Rocks; about 1,600 feet east and 2,700 feet south of the NW corner of sec. 16, T. 13 N., R. 2 E.; 35 degrees, 13 minutes, and 14 seconds north latitude, and 116 degrees, 46 minutes, and 39 seconds west longitude; Paradise Range quadrangle. UTM 11S, 0520210e 3897327n

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 is 59 to 71 degrees F.

Organic matter: 0 to 0.5 percent

Depth to a paralithic contact: 1 to 3 inches

Surface rock fragments: 35 to 60 percent gravel, 0 to 20 percent cobbles, and 0 to 5 percent stones.

Control section -

Clay content: 8 to 18 percent

A horizon
-Value: 4 to 6 dry, and 3 to 5 moist

-Chroma: 2 to 6 dry, and 3 to 8 moist

-Texture of the fine earth: coarse sandy loam or sandy
loam

-Rock fragments: 25 to 55 percent gravel, 0 to 20
percent cobbles, and 0 to 5 percent stones; range is
35 to 70 percent

-Calcium carbonate equivalent: 0 to 1 percent

-Reaction: neutral to moderately alkaline

COMPETING SERIES: These are the Akela, Beach, Dalvord, Haleburu, Hindu, Hulda, Pearce, Razorback, Tecopa, Terlingua and Upspring series. Akela, Beach, Dalvord, Haleburu, Hindu, Hulda, Pearce, Razorback, Tecopa, Terlingua and Upspring series are all greater than 4 inches to a paralithic or lithic contact. In addition, Akela soils form in calcareous material from basaltic alluvium and rhyolitic tuff and the moisture control section is moist in some part for more than 20 days cumulative between June and September; Beach soils form from fine grained metamorphic sandstone and have an A horizon with hues of 2.5YR or 5YR and receive most of their precipitation during the summer months; Haleburu soils formed from volcanic sources and have finer textures; Hindu soils form from limestone or calcareous sedimentary rocks, have a control section dominated by cobbles, and a moisture control section that is moist in some part for more than 20 days cumulative between June and September; Hulda soils are in the 8 to 10 inch precipitation zone; Pearce soils are in the 8 to 12 inch precipitation zone, have finer textures and have calcium carbonate equivalents of 5 to 35 percent; Razorback soils are in the 6 to 12 inch precipitation zone, formed from extrusive igneous rocks and have finer textures; Tecopa soils form from mixed metamorphic and igneous rocks such as schist, gneiss, and quartzite, have a thicker epipedon, contain a larger proportion of medium and finer sands, and are dry during the summer months; Terlingua soils have horizons with accumulations of secondary calcium carbonate and formed in volcanic rock; and Upspring soils form from basic igneous rocks with some pyroclastic material, have a control section that ranges from very gravelly to very stony, and are dry in the moisture control section during the summer.

GEOGRAPHIC SETTING: The Paintrocks soils are on mountains, hills, and pediments. Slope ranges from 2 to 50 percent. The soils formed in material from granitic sources. Elevations are from 2,400 to 5,700 feet. The climate is arid, with hot, dry summers and cool winters. Most precipitation comes in the winter but in some areas it is sporadic. The mean annual precipitation is 3 to 8 inches. The mean annual air temperature is 57 to 69 degrees F. Mean July temperature is about 78 degrees F., and mean January temperature is about 42 degrees F. The frost-free season is 200 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cajon and Langwell (T) soils. Cajon soils have sandy control sections and are very deep. They are on alluvial fans adjacent to pediments. Langwell soils are found on similar landscape positions, have a loamy particle-size control section, and have a lithic contact at 4 to 14 inches.

DRAINAGE AND PERMEABILITY: Excessively drained; high to very high runoff; moderately rapid permeability.

USE AND VEGETATION: Paintrocks soils are used for military exercises and wildlife habitat. The present vegetation is mainly California buckwheat, creosotebush, white bursage, range ratney, Nevada ephedra, Pine bluegrass and desert needlegrass.

DISTRIBUTION AND EXTENT: Mojave Desert of southeastern California. MLRA 30. The series is of small extent.

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

SERIES ESTABLISHED: San Bernardino County, California, Fort Irwin Soil Survey Area, 2000. The name is from a local landscape feature.

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

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

National Cooperative Soil Survey
U.S.A.