LOCATION AQUAPEAK                CA

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

AQUAPEAK SERIES

The Aquapeak series consists of very shallow and shallow, well drained soils that formed in alluvium from granitoid or other igneous rocks. Aquapeak soils are on fan remnants. Slopes range from 0 to 15 percent. The mean annual precipitation is about 100 millimeters (4 inches) and the mean annual air temperature is about 21.5 degrees C (70 degrees F).

TAXONOMIC CLASS: Loamy, mixed, superactive, hyperthermic, shallow Argidic Argidurids

TYPICAL PEDON: Aquapeak very gravelly fine sandy loam, on a northeast-facing, convex, 6 percent slope under sparse desert shrubs at an elevation of 484 meters (1,589 feet). (Colors are for dry soil unless otherwise noted.)

C -- 0 to 5 centimeters (0 to 2 inches) gravel; approximately 15 percent fine gravel, 65 percent medium and coarse gravel, 10 percent cobbles and 2 percent stones; abrupt smooth boundary. (0 to 7 centimeters thick)

A -- 5 to 8 centimeters (2 to 3 inches); pink (7.5YR 7/4) and light yellowish brown (10YR 6/4) gravelly fine sandy loam, strong brown (7.5YR 4/6) moist; moderate thick platy structure parting to weak medium subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common very fine and fine and few medium vesicular pores; 10 percent fine gravel, and 15 percent medium and coarse gravel; violently effervescent; very strongly alkaline (pH 9.1); abrupt wavy boundary. (1 to 10 centimeters thick)

Btkq -- 8 to 27 centimeters (3 to 11 inches); strong brown (7.5YR 5/6) fine sandy loam, strong brown (7.5YR 4/6) moist; moderate medium subangular blocky structure; moderately hard, firm, slightly sticky and moderately plastic; 35 percent, faint, strong brown (7.5YR 4/6) clay films on ped faces; 1 percent fine, distinct, white (10YR 8/1), cylindrical, calcium carbonate masses in the matrix; 10 percent, faint, pink (7.5YR 7/3) silica coats on the bottom of rock fragments; few very fine roots; common very fine and few medium interstitial pores; 5 percent fine gravel and 5 percent medium and coarse gravel; strongly effervescent; strongly alkaline (pH 8.8); abrupt wavy boundary. (11 to 30 centimeters thick)

Bkqm -- 27 to 48 centimeters (11 to 19 inches); pale yellow (2.5Y 8/2) weakly cemented gravelly loamy sand, pale yellow (2.5Y 7/3) moist; duripan with continuous cementation; massive; very hard, very firm, brittle; 10 percent fine gravel and 10 percent medium and coarse gravel; gradual wavy boundary. (20 to 60 centimeters thick)

Bkq1 -- 48 to 84 centimeters (19 to 33 inches); pale yellow (2.5Y 8/2) gravelly loamy sand, very pale brown (10YR 7/4) moist; massive; moderately hard, firm, nonsticky and nonplastic; 40 percent prominent, very pale brown (10YR 8/2) calcium carbonate coats on all sides of rock fragments; 30 percent, faint, very pale brown (10YR 7/3) silica coats on the bottom of rock fragments; 10 percent fine gravel and 10 percent medium and coarse gravel; violently effervescent (17 percent calcium carbonate equivalent in the fine earth fraction); slightly alkaline (pH 7.7); gradual wavy boundary.

Bkq2 -- 84 to 152 centimeters (33 to 60 inches); very pale brown (10YR 8/2) gravelly sand, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; 50 percent prominent, very pale brown (10YR 8/2) calcium carbonate coats on bottom of rock fragments; 30 percent, faint, very pale brown (10YR 7/3) silica coats on the bottom of rock fragments; 15 percent fine gravel and 15 percent medium and coarse gravel; violently effervescent (10 percent calcium carbonate equivalent in the fine earth fraction); slightly alkaline (pH 7.8). (20 to 125 centimeters thick)

TYPE LOCATION: San Bernardino County, California; approximately 3.1 kilometers south southeast of the junction of Highway 62 and Iron Age Road; 35 meters (115 feet) west and 600 meters (1,968 feet) north of the SE corner of section 13, T. 1 S., R. 12 E., San Bernardino Base and Meridian; 34 degrees, 5 minutes and 2.5 seconds north latitude and 115 degrees, 40 minutes and 4.4 seconds west longitude; USGS New Dale 7.5 minute topographic quadrangle; UTM 11S 0622902e 3772274n (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: 35 to 98 percent, with 10 to 40 percent fine gravel,
20 to 85 percent medium and coarse gravel, 3 to 30 percent cobbles, 0 to 5
percent stones and 0 to 2 percent boulders.

Control section -
Depth to the upper boundary of an argillic horizon from the upper boundary of
the A horizon: 1 to 10 centimeters (0.5 to 4 inches).
Depth to the upper boundary of a duripan from the upper boundary of the A
horizon: 12 to 36 centimeters (5 to 14 inches).
Clay content: averages 8 to 18 percent.
Rock fragments: 1 to 30 percent; with 1 to 30 percent gravel and 0 to 5
percent cobbles.
Organic matter: 0 to 0.5 percent.

C horizon (when present)
80 to 98 percent rock fragments; 1 to 20 percent fine gravel, 35 to 85 percent medium to coarse gravel, 3 to 30 percent cobbles, 0 to 5 percent stones.

A horizon
Hue: 7.5YR or 10YR.
Value: 5 to 7, dry; 4 or 5, moist.
Chroma: 3 or 4, dry; 2 to 6, moist.
Clay content: 3 to 15 percent.
Texture of the fine earth: fine sand, fine sandy loam, or loam.
Rock fragments: 15 to 55 percent gravel.
Effervescence: noneffervescent to violently effervescent.
Calcium carbonate equivalent: 0 to 5 percent.
Reaction: slightly alkaline to very strongly alkaline.
Salinity: 0 to 4 dS/m.
Other features: significant quantity of vesicular pores present throughout
horizon.

Btk or Btkq horizon
Hue: 7.5YR or 10YR.
Value: 5 or 6, dry; 4 or 5, moist.
Chroma: 4 to 6, dry or moist.
Clay content: 8 to 20 percent.
Texture of the fine earth: sandy loam, fine sandy loam, or loam.
Rock fragments: 5 to 35 percent; with 3 to 30 percent gravel and 0 to 5
percent cobbles.
Effervescence: noneffervescent to violently effervescent.
Calcium carbonate equivalent: 0 to 10 percent.
Reaction: slightly alkaline to strongly alkaline.
Salinity: 0 to 4 dS/m.
Silica: 0 to 10 percent as coats on underside of rock fragments.

Bkq or Bkqm horizon
Hue: 7.5YR, 10YR, or 2.5Y.
Value: 5 to 8, dry; 4 to 7, moist.
Chroma: 1 to 6, dry; 2 to 6, moist.
Clay content: 3 to 12 percent.
Texture of the fine earth: sand, loamy sand, or sandy loam.
Rock fragments: 5 to 60 percent; with 5 to 45 percent gravel, 0 to 10
percent cobbles and 0 to 10 percent stones.
Effervescence: slightly to violently effervescent.
Calcium carbonate equivalent: 1 to 20 percent.
Reaction: slightly alkaline to strongly alkaline.
Salinity: 0 to 4 dS/m.
Silica: 0 to 40 percent as coats on underside of rock fragments.
Cementation: 75 to 100 percent, weak to moderate cementation.

Ck or C horizon (when present)
Value: 5 to 7, dry; 4 or 5, moist.
Chroma: 2 to 4, dry; 3 to 6, moist.
Clay content: 1 to 6 percent.
Texture of the fine earth: sand or loamy sand.
Rock fragments: 5 to 45 percent; with 5 to 35 percent gravel and 0 to 10
percent cobbles.
Effervescence: slightly to violently effervescent.
Calcium carbonate equivalent: 1 to 5 percent.
Reaction: slightly alkaline to strongly alkaline.
Salinity: 0 to 6 dS/m.

COMPETING SERIES: There are no competing series at this time.

GEOGRAPHIC SETTING: Aquapeak soils are on fan remnants. Slopes range from 0 to 15 percent. These soils formed in alluvium from granitoid or mixed igneous rocks. Elevations range from 458 to 750 meters (1,500 to 2,460 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 Buzzardsprings, Carpetflat, Coxpin, Dalelake and Pintobasin soils. Buzzardsprings, Carpetflat and Coxpin soils are on similar landscape positions, Dalelake soils are on adjacent sandsheets, and Pintobasin soils are on adjacent fan aprons. Buzzardsprings, Carpetflat and Coxpin soils do not have an argillic horizon. In addition, Buzzardsprings soils do not have a duripan while Coxpin soils are 36 to 50 centimeters deep to a duripan. Dalelake and Pintobasin soils are very deep, are sandy throughout the particle-size control section and have no diagnostic horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; low or medium runoff; moderately high or high saturated hydraulic conductivity above the duripan, low saturated hydraulic conductivity within the duripan and high saturated hydraulic conductivity below the duripan.

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

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: San Bernardino County, California, Joshua Tree National Park Soil Survey, 2012. The name is from Aqua Peak, a location in the soil survey area.

REMARKS: Diagnostic horizons and features in this pedon include:

C horizon - from a depth of 0 to 5 centimeters.
Ochric epipedon - from a depth of 5 to 8 centimeters (A horizon).
Argillic horizon - from a depth of 8 to 27 centimeters (Btkq horizon).
Duripan - from a depth of 27 to 48 centimeters (Bkqm horizon).
Calcic horizon - the zone beginning at 48 centimeters (Bkq horizons).
Particle-size control section - from a depth of 0 to 27 centimeters (C, A and
Btkq horizons).

ADDITIONAL DATA: NASIS User Pedon ID: 12476050-X.

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

---

National Cooperative Soil Survey
U.S.A.