LOCATION MISSIONSWEET            CA

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

MISSIONSWEET SERIES

The Missionsweet series consists of shallow, well drained soils that formed in alluvium from igneous rock. Missionsweet soils are on sideslopes of fan remnants. Slopes range from 8 to 30 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 Cambidic Haplodurids

TYPICAL PEDON: Missionsweet very gravelly loam on a north-northwest facing, linear, 13 percent slope under desert shrubs at an elevation of 645 meters (2,115 feet). (Colors are for dry soil unless otherwise noted).

C -- 0 to 5 centimeters (0 to 2 inches) gravel; with approximately 75 percent gravel, 15 percent cobbles, and 1 percent stones. (2 to 5 centimeters thick)

A -- 5 to 7 centimeters (2 to 3 inches); light yellowish brown (10YR 6/4) very gravelly loam, brown (10YR 4/3) moist; weak thin platy structure parting to weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine and fine tubular pores; 20 percent fine gravel, 15 percent medium and coarse gravel and 10 percent cobbles; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (2 to 6 centimeters thick)

Bk -- 7 to 28 centimeters (3 to 11 inches); light yellowish brown (10YR 6/4) extremely gravelly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and common medium roots; few fine tubular pores; 3 percent, white (10YR 8/1) calcium carbonate threads throughout the matrix; 30 percent fine gravel, 20 percent medium and coarse gravel and 12 percent cobbles; violently effervescent; moderately alkaline (pH 8.2); abrupt irregular boundary.

Bkq -- 28 to 43 centimeters (11 to 17 centimeters); pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 4/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; few fine tubular pores; 30 percent, white (10YR 8/1) very strongly cemented durinodes in the matrix, 25 percent fine gravel, 15 percent medium and coarse gravel and 12 percent cobbles; violently effervescent; moderately alkaline (pH 8.0); abrupt irregular boundary. (Combined thickness of the Bk horizons is 23 to 39 centimeters).

Bkqm -- 43 to 68 centimeters (17 to 27 inches); white (10YR 8/1) strongly cemented sandy loam, light gray (10YR 7/2) moist; duripan with 90 percent cementation; massive; moderately hard, firm and brittle; violently effervescent.

TYPE LOCATION: Riverside County, California; 310 meters (1,017 feet) west and 535 meters (1,754 feet) north of the SE corner of section 33, T. 3 S., R. 13 E., San Bernardino Base and Meridian; 33 degrees, 51 minutes and 51.2 seconds north latitude and 115 degrees, 37 minutes and 12 seconds west longitude; USGS Buzzard Spring 7.5 minute topographic quadrangle; UTM 11S 0627646e 3747957n (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 convection storms. The soils have
a typic-aridic soil moisture regime.

Soil temperature: 22 to 25 degrees C (72 to 77 F).
Organic matter: 0 to 0.5 percent.
Surface rock fragments: 85 to 95 percent; with 65 to 95 percent gravel, 10
to 20 percent cobbles and 0 to 5 percent stones.

Control section -
Depth to the upper boundary of a duripan: 36 to 50 centimeters (14 to 20
inches).
Clay content: averages 8 to 12 percent.
Rock fragments: averages 55 to 90 percent; with 40 to 80 percent gravel, 0
to 40 percent cobbles and 0 to 10 percent stones.

C horizon
85 to 95 percent; with 35 to 55 percent fine gravel, 30 to 50 percent
medium and coarse gravel, 10 to 35 percent cobbles and 0 to 5 percent
stones.

A horizon
Hue: 7.5YR or 10YR moist.
Value: 3 or 4 moist.
Chroma: 3 or 4 dry, 2 to 4 moist.
Clay content: 8 to 14 percent.
Rock fragments: 40 to 60 percent; with 30 to 50 percent gravel and 3 to 10
percent cobbles.
Effervescence: strongly or violently effervescent.
Calcium carbonate equivalent: 0 to 5 percent.

Bk or Bkq horizon
Hue: 7.5YR or 10YR.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 to 4 dry, 3 or 4 moist.
Texture of the fine earth: sandy loam or loam.
Clay content: 8 to 12 percent.
Rock fragments: 40 to 85 percent; with 35 to 60 percent gravel and 2 to 15
percent cobbles.
Calcium carbonate equivalent: 5 to 10 percent.
Visible secondary carbonates: 0 to 20 percent as coats on rock fragments.
Silica: 0 to 30 percent as strongly cemented durinodes within the matrix.
Cementation: 5 to 30 percent, very weakly or weakly cemented.

Bkqm horizon
Cementation: 90 to 100 percent, moderately to very strongly cemented.

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

GEOGRAPHIC SETTING: Missionsweet soils are on sideslopes of fan remnants. Slopes range from 8 to 30 percent. These soils formed in alluvium from igneous rock. Elevations range from 470 to 780 meters (1,542 to 2,558 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 (68 to 73.5 degrees F), and the frost-free season is 300 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carpetflat, Carrizo, Friedliver and Oldale soils. Carpetflat, Friedliver and Oldale soils are found on summits of fan remnants. Carpetflat soils have a loamy particle-size control section above the duripan. Friedliver and Oldale soils have coarse-loamy and loamy-skeletal particle-size control sections, respectively, have an argillic horizon and do not have a duripan. Carrizo soils are in drainageways, are very deep, have a sandy-skeletal particle-size control section and do not have a duripan.

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

USE AND VEGETATION: Missionsweet soils are used for recreation and wildlife habitat. The present vegetation is mainly creosote bush, white ratany, burrobush and water jacket.

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, Joshua Tree National Park Soil Survey, 2012. The name is from a site 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 7 centimeters (A horizon).
Particle-size control section - from a depth of 25 to 43 centimeters (part
of the Bk and the Bkq horizons).
Duripan - the zone beginning at 43 centimeters (Bkqm horizon).

ADDITIONAL DATA: NASIS User Pedon ID: 794-LL-6.

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 5/2012. ET

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National Cooperative Soil Survey
U.S.A.