LOCATION CARPETFLAT              CA

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

CARPETFLAT SERIES

The Carpetflat series consists of very shallow and shallow, somewhat excessively drained soils that formed in alluvium from granitoid rocks. Carpetflat soils are on summits of fan remnants. Slopes range from 0 to 4 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, shallow Typic Haplodurids

TYPICAL PEDON: Carpetflat gravel on a west-facing, linear, 1 percent slope under desert shrubs at an elevation of 631 meters (2,071 feet). (Colors are for dry soil unless otherwise noted).

C -- 0 to 6 centimeters (0 to 2.5 inches) gravel; with approximately 40 percent fine gravel, 32 percent medium and coarse gravel, 20 percent cobbles and 3 percent stones; abrupt wavy boundary. (0 to 7 centimeters thick)

A -- 6 to 11 centimeters (2.5 to 4.5 inches); pale brown (10YR 6/3) gravelly silt loam, dark yellowish brown (10YR 4/4) moist; weak thin platy structure; hard, very friable, moderately sticky and moderately plastic; very few very fine roots; many fine vesicular pores; 10 percent fine gravel, 5 percent medium and coarse gravel and 3 percent cobbles; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (2 to 6 centimeters thick)

Bw -- 11 to 19 centimeters (4.5 to 7.5 inches); pale brown (10YR 6/3) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak thin platy parting to weak fine subangular blocky structure; slightly hard, firm, nonsticky and nonplastic; few fine tubular pores; 30 percent fine gravel, 20 percent medium and coarse gravel and 5 percent cobbles; violently effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (0 to 14 centimeters thick)

Bk -- 19 to 34 centimeters (7.5 to 13.5 inches); pale brown (10YR 6/3) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; loose, slightly sticky and slightly plastic; 2 percent fine carbonate filaments throughout matrix and 3 percent thick carbonate coats on bottom sides of rock fragments; few very fine and fine tubular pores; 20 percent fine gravel, 10 percent medium and coarse gravel and 5 percent cobbles; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (0 to 26 centimeters thick)

Bkqm1 -- 34 to 41 centimeters (13.5 to 16 inches); very pale brown (10YR 8/2) weakly to moderately cemented loamy sand, very pale brown (10YR 7/3) moist; duripan with 95 percent cementation; massive; moderately hard, firm, brittle; violently effervescent.

Bkqm2 -- 41 to 66 centimeters (16 to 26 inches); very pale brown (10YR 8/2) very strongly cemented duripan with 100 percent cementation, very pale brown (10YR 7/3) moist; massive; extremely hard, very firm, brittle; violently effervescent.

TYPE LOCATION: Riverside County, California; 770 meters (2,525 feet) west and 735 meters (2,411 feet) south of the NE corner of section 33, T. 3 S., R. 13 E., San Bernardino Base and Meridian; 33 degrees, 52 minutes and 1.6 seconds north latitude and 115 degrees, 37 minutes and 30.1 seconds west longitude; USGS Conejo Well, CA 7.5 minute topographic quadrangle; UTM 11S 0627177e 3748273n (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 77 F).
Surface rock fragments: 70 to 100 percent; with 60 to 80 percent gravel, 10
to 25 percent cobbles and 0 to 5 percent stones.

Control section -
Rock fragments: averages 35 to 50 percent.
Clay content: 8 to 12 percent.
Organic matter: 0 to 0.5 percent.
Depth to the upper boundary of a duripan: 18 to 36 centimeters (7 to 14
inches).

C horizon (where present)
80 to 100 percent rock fragments; with 60 to 80 percent gravel, 10 to 25
percent cobbles and 0 to 5 percent stones.

A horizon
Hue: 7.5YR, 10YR or 2.5Y.
Value: 6 to 8, dry and 4 or 5, moist.
Chroma: 3 or 4, dry or moist.
Texture of the fine earth: fine sand, sandy loam or silt loam.
Clay content: 1 to 20 percent.
Rock fragments: 15 to 55 percent; with 15 to 45 percent gravel and 0 to 10
percent cobbles.
Effervescence: strongly or violently effervescent.
Calcium carbonate equivalent: 0 to 5 percent.
Reaction: moderately or strongly alkaline.
Note: some pedons are characterized by vesicular pores in this horizon.

Bw and/or Bk horizons (where present)
Hue: 7.5YR or 10YR.
Value: 6 or 7, dry and 4 or 5, moist.
Chroma: 3 or 4, dry and 3 to 6, moist.
Texture of the fine earth: sandy loam or silt loam.
Clay content: 8 to 12 percent.
Rock fragments: 20 to 55 percent; with 20 to 55 percent gravel and 0 to 5
percent cobbles.
Calcium carbonate equivalent: 0 to 10 percent.
Visible secondary carbonates: 0 to 20 percent as coats on rock fragments.

Bkq or Bkqm horizons
Hue: 7.5YR or 10YR.
Chroma: 1 or 2, dry and 1 to 3, moist.
Cementation: weakly to moderately cemented in the upper part and very
strongly cemented in the lower part; 50 to 100 percent continuity.

COMPETING SERIES: This is the Rainbowsend (CA) series. Rainbowsend soils are 36 to 50 centimeters deep to the upper boundary of a duripan.

GEOGRAPHIC SETTING: Carpetflat soils are on summits of fan remnants. Slopes range from 0 to 4 percent. These soils formed in alluvium from igneous rock. Elevations range from 470 to 775 meters (1,540 to 2,540 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) and the mean annual air temperature is 20 to 23 degrees C (68 to 73.5 degrees F). The frost-free season is 300 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aquapeak, Missionsweet and Pintobasin soils. Aquapeak soils are on similar landscape positions and have an argillic horizon above the duripan. Missionsweet soils are on steeper sideslopes of fan remnants and have a less than strongly cemented duripan with an upper boundary 36 to 50 centimeters from the soil surface. Pintobasin soils are on adjacent fan aprons, are very deep, have sandy particle-size control sections and do not have diagnostic horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; low to medium runoff; moderately high saturated hydraulic conductivity in the surface horizon, high saturated hydraulic conductivity above the duripan and moderately low saturated hydraulic conductivity within the duripan.

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

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

REMARKS: Diagnostic horizons and features in this pedon include:

C horizon - from a depth of 0 to 6 centimeters.
Ochric epipedon - from a depth of 6 to 11 centimeters (A horizon).
Duripan - the zone beginning at 34 centimeters (Bkqm1 and Bkqm2).
Particle-size control section - from a depth of 0 to 34 centimeters (A, AB
and Bk horizons).

ADDITIONAL DATA: NASIS Pedon User ID: 794-LL-7.

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 9/2012. ET

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National Cooperative Soil Survey
U.S.A.