LOCATION OLYMPUS CA

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

OLYMPUS SERIES

The Olympus series consists of very deep, well drained soils formed in granitic alluvium. The Olympus soils are on alluvial fans. Slope ranges from 2 to 8 percent. The mean annual precipitation is about 4 inches and the mean annual temperature is about 67 degrees F.

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

TYPICAL PEDON: On Olympus-Cajon complex, 2 to 8 percent slopes at an elevation of 2,550 feet. (Colors are for dry soil unless otherwise stated. The soil surface is covered by 35 percent gravel.

A -- 0 to 1 inch; dark yellowish brown (10YR 4/4) gravelly loamy sand, brown (10YR 4/3) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots throughout; strongly effervescent; 30 percent gravel; slightly alkaline (pH 7.6); abrupt smooth boundary. (1 to 7 inches thick)

C1 -- 1 to 12 inches; yellowish brown (10YR 5/4) gravelly loamy sand, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, slighty sticky and slightly plastic; few fine and medium roots throughout; strongly effervescent; 15 percent gravel; moderately alkaline (pH 8.2); clear smooth boundary.

C2 -- 12 to 27 inches; yellowish brown (10YR 5/4) gravelly loamy sand, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; few fine and medium roots in cracks; strongly effervescent; 30 percent gravel; moderately alkaline (pH 8.2); abrupt smooth boundary. (Combined thickness of C horizons is 19 to 35 inches.)

2Btk1 -- 27 to 47 inches; strong brown (7.5YR 4/6) gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, sticky and plastic; few fine and medium roots in cracks; few thin coats on ped faces and few thin threads of calcium carbonate throughout; strongly effervescent; 30 percent gravel; moderately alkaline (pH 8.2); clear smooth boundary.

2Btk2 -- 47 to 55 inches; light yellowish brown (10YR 6/4) sandy loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots in cracks; few masses and threads of calcium carbonate throughout; strongly effervescent; 5 percent gravel; moderately alkaline (pH 8.2); clear smooth boundary. (Combined thickness of 2Btk horizons is 16 to 40 inches.)

2Ck -- 55 to 83 inches; very pale brown (10YR 7/3) gravelly sandy loam, yellowish brown (10YR 5/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; strongly effervescent; 25 percent gravel; moderately alkaline (pH 8.3).

TYPE LOCATION: San Bernardino County, California; about 2,500 feet west of Fort Irwin Road, 1,500 feet west and 1,150 feet south of the northeast corner of sec. 3, T. 12 N., R. 2 E; 35 degrees, 10 minutes, and 03 seconds north latitude, and 116 degrees, 45 minutes, and 19 seconds west longitude; Paradise Range quadrangle. (UTM 11S, 0522283e and 3891488n)

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: 66 to 72 degrees F.

Organic matter: 0 to 0.5 percent

Depth to upper boundary of argillic: 20 to 40 inches

Surface rock fragments: 30 to 65 percent gravel

Control section
Clay content: 18 to 35 percent

A horizon
Hue: 7.5YR or 10YR

Value: 4 to 6 dry, and 4 or 5 moist

Chroma: 3 or 4 dry or moist

Clay content: 2 to 8 percent

Rock fragments: 25 to 55 percent gravel

Calcium carbonate equivalent: 1 to 5 percent

Reaction: neutral or slightly alkaline

C horizon
Hue: 7.5YR or 10YR

Value: 5 dry and 4 to 5 moist

Chroma: 3, 4, or 6 dry, and 3 to 4 moist

Clay content: 2 to 8 percent

Rock fragments: 10 to 50 percent gravel

Calcium carbonate equivalent: 1 to 5 percent

Reaction: slightly or moderately alkaline

2Btk horizon
Hue: 7.5YR or 10YR

Value: 4 to 6 dry or moist

Chroma: 4 to 6 dry and 3 or 4 moist

Texture of the fine earth: sandy loam or sandy clay loam

Rock fragments: 5 to 30 percent gravel

Calcium carbonate equivalent: 1 to 5 percent

Reaction: slightly or moderately alkaline

Clay content: 18 to 35 percent in the upper part and 10 to 18 percent in the lower part

2Ck horizon
Value: 5 to 7 dry or moist

Chroma: 3 to 4 dry or moist

Rock fragments: 20 to 30 percent gravel

Texture of the fine earth: loamy sand or sandy loam

Clay content: 5 to 15 percent

Calcium carbonate equivalent: 1 to 5 percent

COMPETING SERIES: This is the Maljamar and Pipeflat series. Maljamar soils receive more rainfall and are moist for more than 20 days, cumulative, in some part of the moisture control section between July and October. Pipeflat soils have less than 18 percent clay within the control section and the surface horizons consist of eolian sands.

GEOGRAPHIC SETTING: The Olympus soils are on alluvial fans. Slope ranges from 2 to 8 percent. The soils formed in material from granitic sources. Elevations are 1,900 to 3,100 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 6 inches. The mean annual temperature is 64 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 240 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ambrosia, Cajon, and Garlock soils. Ambrosia soils are found on upper parts of alluvial fans and have a calcic horizon. Cajon soils are found in drainage ways and channels and have a sandy particle size control section. Garlock soils have a fine-loamy particle-size control section and are found on similar landscape positions.

DRAINAGE AND PERMEABILITY: Well drained; very low to low runoff; rapid permeability in the upper part of the profile and moderately slow permeability in the upper part of the 2Btk horizon. Some pedons have loamy sand textures below the 2Btk with moderately slow over rapid permeability.

USE AND VEGETATION: Olympus soils are used for military exercises and wildlife habitat. The present vegetation is mainly creosotebush, white bursage, and California ephedra.

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 an abandoned mine site.

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

1. ochric epipedon -- 0 to 1 inches
2. argillic horizon -- 27 to 55 inches (2Btk1 and 2Btk2)

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

National Cooperative Soil Survey
U.S.A.