LOCATION DALVORD            CA

DALVORD SERIES

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

TYPICAL PEDON: On Dalvord-Rock outcrop-Langwell complex, 15 to 50 percent slopes at an elevation of 2,732 feet. (Colors are for dry soil unless otherwise noted.)

The soil surface is partially covered with 10 percent gravel, 10 percent cobbles, and 45 percent stones and boulders.

A1-- 0 to 1 inch; pale brown (10YR 6/3) extremely stony sandy loam, brown (10YR 5/3) moist; weak thin platy to weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few very fine roots throughout; common tubular pores throughout; violently effervescent (calcium carbonate equivalent of 1 percent); 35 percent gravel, 10 percent cobbles, and 20 percent stones and boulders; moderately alkaline (pH 8.2); abrupt wavy boundary.

A2-- 1 to 6 inches; very pale brown (10YR 7/3) very gravelly coarse sandy loam, brown (10YR 5/3) moist; weak fine subangular blocky to medium moderate granular structure; soft, very friable, slightly sticky and slightly plastic; few very fine roots in cracks; few fine tubular pores throughout; violently effervescent (calcium carbonate equivalent of 5 percent); 35 percent gravel and 5 percent cobbles; moderately alkaline (pH 8.3); abrupt smooth boundary. (Combined thickness of the A horizon is 1 to 14 inches.)

R-- 6+ inches; unweathered, fractured granitic bedrock with pockets of weathered bedrock material of moderate to high excavation difficulty.

TYPE LOCATION: San Bernardino County, California; about 1,000 feet north and 400 feet east of the center of sec. 2, T. 12 N., R. 2 E.; 35 degrees, 10 minutes, and 01 seconds north latitude, and 116 degrees, 44 minutes, and 08 seconds west longitude; Langford Well quadrangle. UTM 11S, 0524120e 3891391n (Datum=NAS-C)

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 72 degrees F.

Organic matter: 0 to 0.5 percent

Depth to bedrock: 1 to 14 inches

Surface rock fragments: 5 to 85 percent gravel, 0 to 25 percent cobbles, and 0 to 50 percent stones.

Control section -

Clay: 5 to 20 percent

A Horizon
-Hue: 10YR or 2.5Y
-Value: 5 to 7 dry and 3 to 6 moist
-Chroma: 2 to 4 dry or moist
-Texture of the fine earth: coarse sandy loam or sandy loam
-Rock fragments: 20 to 85 percent gravel, 0 to 40
percent cobbles, and 0 to 30 percent stones; range is
40 to 85 percent
-Calcium carbonate equivalent: 1 to 10 percent
-Reaction: slightly or moderately alkaline
-Electrical conductivity: 0 to 2 dS/m
-Sodium adsorption ratio: 0 to 4

Note- Some pedons have a weak Bt horizon with similar characteristics to the A horizon. These horizons do not have the necessary clay increase to be an argillic.

C Horizon (when present)
-Hue: 10YR
-Value: 5 to 7 dry and 3 to 6 moist
-Chroma: 2 to 4 dry or moist
-Texture of the fine earth: coarse sandy loam or sandy loam
-Rock fragments: range is 60 to 85 percent, usually gravel
with 0 to 25 percent cobbles, and 0 to 30 percent stones
-Calcium carbonate equivalent: 1 to 5 percent
-Reaction: slightly or moderately alkaline
-Electrical conductivity: 0 to 2 dS/m
-Sodium adsorption ratio: 0 to 4

R horizon
-Unweathered, slightly to highly fractured granitic
bedrock, with pockets of slightly to moderately
weathered bedrock material of moderate to extremely high
excavation difficulty.

COMPETING SERIES: These are the Akela, Beach, Haleburu, Hindu, Hulda, Noble Pass, Pearce, Razorback, Tecopa, Terlingua and Upspring series. 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. Noble Pass soils formed in rhyolitic parent material. 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. In addition, they have thinner epipedons, 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. 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 Dalvord soils are on mountains, hills, and pediments. Slope ranges from 8 to 75 percent. The soils formed in colluvium and residuum from granite. Elevations are from 1,900 to 5,100 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 2 to 8 inches. The mean annual air temperature is 57 to 70 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 Etinarg, Goldroad, and Langwell soils. Etinarg soils are found on similar landscape positions at higher elevations and have an argillic horizon. They are in a mesic soil temperature regime. Goldroad soils are on adjacent south facing slopes and lower elevations. They are in a hyperthermic soil temperature regime. Langwell soils are found on similar landscape positions and have a loamy particle-size control section.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very high runoff; moderately rapid permeability over bedrock.

USE AND VEGETATION: Dalvord soils are used for military exercises and wildlife habitat. The present vegetation is creosotebush, white bursage, encelia, Anderson wolfberry, and range ratany.

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

MLRA OFFICE RESPONSIBLE: Davis, California.

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

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

1. Ochric epipedon -- 0 to 6 inches (A1 and A2 horizons)
2. Particle-size control section -- 0 to 6 inches (A1 and
A2 horizons)
2. Lithic contact -- the zone beginning at 6 inches (R)