LOCATION BLACKEAGLE              CA

Established Series
Rev:CAH/PBF/ET
04/2015

BLACKEAGLE SERIES

The Blackeagle series consists of shallow, somewhat excessively drained soils that formed in colluvium and/or residuum from gneissic and/or granitoid rocks. The Blackeagle soils are on hills and mountains. Slopes range from 15 to 75 percent. The mean annual precipitation is about 100 millimeters (4 inches) and the mean annual air temperature is about 21.5 degrees C (71 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, hyperthermic Lithic Haplocambids

TYPICAL PEDON: Blackeagle gravel, on a north-facing, linear, 45 percent slope under desert shrubs at an elevation of 698 meters (2,290 feet). (Colors are for dry soil unless otherwise noted.) The surface is covered by approximately 64 percent gravel, 20 percent cobbles and 1 percent stones.

C -- 0 to 5 centimeters (0 to 2 inches); gravel; 64 percent gravel, 20 percent cobbles and 1 percent stone; abrupt smooth boundary. (4 to 20 centimeters thick)

A -- 5 to 8 centimeters (2 to 3 inches); pale brown (10YR 6/3) very gravelly loamy sand, dark grayish brown (10YR 4/2) moist; weak thin platy structure parting to weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; few medium tubular pores; 50 percent gravel and 5 percent cobbles; slightly effervescent; neutral (pH 6.6); clear wavy boundary. (2 to 6 centimeters thick)

AB -- 8 to 28 centimeters (3 to 11 inches); pale brown (10YR 6/3) extremely gravelly loamy sand, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and few fine and medium roots; common fine tubular pores; 55 percent gravel and 20 percent cobbles; strongly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (0 to 20 centimeters thick)

Bw -- 28 to 41 centimeters (11 to 16 inches); yellowish brown (10YR 5/6) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; few fine and medium roots; 40 percent gravel and 5 percent cobbles; strongly effervescent; slightly alkaline (pH 7.8); clear irregular boundary. (15 to 35 centimeters thick)

R -- 41 centimeters (16 inches); unweathered gneissic bedrock of high to very high excavation difficulty with a thin rind of paralithic material (0 to 4 centimeters thick) at the soil and rock interface.

TYPE LOCATION: Riverside County, California; 76 meters (250 feet) east and 945 meters (3,100 feet) south of the NE corner of sec. 36, T. 3 S., R. 13 E., San Bernardino Base and Meridian; 33 degrees, 51 minutes and 42 seconds north latitude and 115 degrees, 39 minutes and 54 seconds west longitude; USGS Conejo Well 7.5 minute topographic quadrangle; UTM 11S 623488e 3747612n (DTM: NAD83).

RANGE IN CHARACTERISTICS:

Soil moisture control section: usually dry, moist in some parts for short periods during winter and early spring and for 10 to 20 days cumulative between July and September following summer convection storms. The soils have a typic-aridic soil moisture regime.

Soil temperature: 22 to 25 degrees C (72 to 79 degrees F).
Organic matter: 0 to 0.5 percent
Surface rock fragments: range of 80 to 95 percent; with 60 to 65 percent gravel, 20 to 30 percent cobbles, 0 to 5 percent stones, and 0 to 2 percent boulders.

Control section
Depth to upper boundary of the cambic horizon: 6 to 25 centimeters.
Depth to a lithic contact: 36 to 50 centimeters.

C horizon
In lieu of texture: gravel, cobbles or stones.
Rock fragments: 80 to 95 percent; with 35 to 65 percent gravel, 20 to 40 percent cobbles, 1 to 20 percent stones, and 0 to 5 percent boulders.

A horizon
Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 to 4, dry or moist.
Texture of the fine earth: loamy sand, sandy loam or fine sandy loam.
Clay content: 4 to 12 percent.
Rock fragments: 40 to 70 percent, dominantly gravel.
Effervescence: very slightly or slightly effervescent.
Reaction: slightly acid or neutral.

AB horizon (when present)
Chroma: 3 or 4, dry.
Clay content: 8 to 9 percent.
Rock fragments: 45 to 75 percent, dominantly gravel.
Effervescence: strongly or violently effervescent.

Bw or Bk horizon
Value: 5 or 6, dry.
Chroma: 4 to 6, dry and 3 to 4, moist.
Texture of the fine earth: sandy loam or fine sandy loam.
Clay content: 8 to 18 percent.
Rock fragments: 35 to 65 percent, dominantly gravel.
Effervescence: slightly to violently effervescent.
Reaction: neutral or slightly alkaline.
Visible secondary carbonates: 0 to 20 percent as coats on bottom of rock fragments and 0 to 3 percent as masses on bottom of rock fragments.

COMPETING SERIES: These are the Angelpoint (CA) and Lomitas (AZ) series. Angelpoint soils are less than 35 centimeters to a lithic contact. Lomitas soils have a moisture control section that is moist in some part for more than 20 days, cumulative, between July and September, and are formed mainly from extrusive volcanic bedrock.

GEOGRAPHIC SETTING: Blackeagle soils are on hills and mountains. Slopes range from 15 to 75 percent. These soils formed in colluvium and/or residuum from gneissic and/or granitoid rocks. Elevations range from 340 to 1215 meters (1,510 to 3,985 feet). The climate is arid with hot, dry summers and warm, moist winters. The mean annual precipitation is 75 to 125 millimeters (3 to 5 inches); mean annual air temperature is 20 to 23 degrees C (63 to 73 degrees F), and the frost-free season is 300 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aguilareal, Carrizo, Goldenbell, Jadestorm, Rainbowsend and Supplymine soils. Aguilareal soils are found on cooler, adjacent backslopes and have a thermic temperature regime. Carrizo soils are very deep, have sandy-skeletal particle-size control sections and are in drainageways. Goldenbell soils are on summits of nearby fan remnants and have a diagnostic argillic horizon above a duripan. Jadestorm soils are on similar landscape positions, do not have a diagnostic cambic horizon and are shallow and very shallow to a paralithic contact. Rainbowend soils are on nearby fan remnants and have a duripan. Supplymine soils are on adjacent backslopes and have a calcic horizon above a moderately deep lithic contact.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; high to very high runoff; moderately high saturated hydraulic conductivity above the bedrock and moderately low within the bedrock.

USE AND VEGETATION: Blackeagle soils are used for recreation and wildlife habitat. The present vegetation is mainly creosote bush, brittlebush, and burrobush.

DISTRIBUTION AND EXTENT: southern Mojave Desert of southeastern California; MLRA 30. These soils are of moderate extent.

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

SERIES ESTABLISHED: Riverside County, California, Soil Survey of Joshua Tree National Park, 2012. The name is from a historic mine in the soil survey area.

REMARKS: Diagnostic horizons and features in this pedon include:

C horizon - from a depth of 0 to 5 centimeters (C horizon).
Ochric epipedon - from a depth of 5 to 23 centimeters (A and most of AB horizons)
Cambic horizon - from a depth of 28 to 46 centimeters (Bw horizon)
Particle-size control section - from a depth of 25 to 46 centimeters (bottom of AB and Bw horizons)
Lithic contact - the zone beginning at 46 centimeters (R horizon)

ADDITIONAL DATA: NASIS Pedon User ID: 794-DD-11.

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 5/2012. ET

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National Cooperative Soil Survey
U.S.A.