LOCATION DESFIREX CA

Established Series
Rev. JCR/LJL/ET
04/2015

DESFIREX SERIES

The Desfirex series consists of moderately deep to a duripan, well drained soils that formed in sandy alluvium derived from granite. The Desfirex soils are on fan remnants and have slopes of 2 to 4 percent. The mean annual precipitation is about 4 inches and the mean annual air temperature is about 68 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Argidic Argidurids

TYPICAL PEDON: Narea-Desfirex-Edalph complex, 2 to 4 percent slopes at an elevation of 2680 feet. (Colors are for dry soil unless otherwise noted.) The surface is covered by approximately 10 percent gravel.

A1--0 to 2 inches; light yellowish brown (10YR 6/4) loamy coarse sand, dark yellowish brown (10YR 4/4) moist; moderate thin and platy structure; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; many very fine vesicular pores; 10 percent gravel; moderately alkaline (pH 8.2); abrupt wavy boundary.

A2--2 to 5 inches; light yellowish brown (10YR 6/4) loamy coarse sand, dark yellowish brown (10YR 4/4) moist; moderate medium and coarse subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and common fine roots; many very fine and fine tubular pores; 10 percent gravel; strongly alkaline (pH 8.7); clear wavy boundary. (Combined thickness of the A horizons range from 4 to 10 inches).

Btk1--5 to 12 inches; light yellowish brown (10YR 6/4) coarse sandy loam, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; very hard, firm, slightly sticky and slightly plastic; common very fine, fine and few medium roots between peds; common very fine tubular pores; 40 percent discontinuous distinct reddish yellow (7.5YR 6/6) clay bridging between sand grains; 30 percent discontinuous distinct reddish yellow (7.5YR 6/6) clay films on faces of peds and pores; 7 percent very thin lime coats on undersides of rock fragments; 2 percent fine irregular soft carbonate threads; 10 percent gravel; slightly effervescent (1 percent calcium carbonate equivalence); strongly alkaline (pH 8.6); clear wavy boundary.

Btk2--12 to 23 inches; light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 4/4) moist; strong medium and coarse subangular blocky structure; extremely hard, very firm, sticky and plastic; common very fine and few fine roots between peds; common very fine tubular pores; 30 percent discontinuous prominent reddish yellow (7.5YR 6/6) clay bridging between sand grains; 15 percent discontinuous prominent reddish yellow (7.5YR 6/6) clay films on faces of peds and pores; 5 percent thin lime coats on undersides of rock fragments; 3 percent very fine and fine irregular carbonate threads; 10 percent gravel; strongly effervescent (2 percent calcium carbonate equivalence); strongly alkaline (pH 8.8); clear wavy boundary. (Combined thickness of the Btk horizons range from 15 to 25 inches).

Bkq--23 to 28 inches; light yellowish brown (10YR 6/4) loamy coarse sand, yellowish brown (10YR 5/4) moist; massive; moderately hard, friable, nonsticky and nonplastic; few very fine roots; common fine and very fine tubular pores; 5 percent thin lime coats on undersides of rock fragments; 7 percent very coarse and extremely coarse rounded very pale brown (10YR 8/2) soft masses of carbonate; 35 percent very coarse and extremely coarse irregular and platelike brownish yellow (10YR 6/6) hard durinodes throughout; 3 percent thin discontinuous laminar caps throughout; 10 percent gravel; violently effervescent (19 percent calcium carbonate equivalent); very strongly alkaline (pH 9.1); clear broken boundary. (0 to 5 inches thick).

Bkqm--28 to 32 inches; very pale brown (10YR 8/2) weakly cemented duripan, light gray (10YR 7/2) moist; massive; extremely hard, very firm, brittle; clear smooth boundary. (3 to 5 inches thick).

Bkq'--32 to 43 inches; very pale brown (10YR 7/4) loamy coarse sand, yellowish brown (10YR 5/4) moist; massive; very hard, friable, nonsticky and nonplastic; common very fine and fine roots; few very fine tubular pores; 5 percent thin lime coats on undersides of coarse fragments; 8 percent very coarse and extremely coarse rounded very pale brown (10YR 8/2) soft masses of carbonate; 45 percent very coarse and extremely coarse irregular and plate-like brownish yellow (10YR 6/6) hard durinodes throughout; 1 percent thin discontinuous laminar caps throughout; electrical conductivity of 1 dS/m; sodium absorption ratio is 11; 10 percent gravel; violently effervescent (17 percent calcium carbonate equivalent); strongly alkaline (pH 9.0); clear irregular boundary. (10 to 15 inches thick).

Ckqn--43 to 60 inches; pale yellow (2.5Y 8/3) stratified very gravelly coarse sand through coarse sand, light olive brown (2.5Y 5/3) moist; single grain; loose, nonsticky and nonplastic; 5 percent thin lime coats on undersides of coarse fragments; 5 percent very coarse and extremely coarse rounded very pale brown (10YR 8/2) soft masses of carbonate; 10 percent coarse cylindrical brownish yellow (10YR 6/6) very hard durinodes; electrical conductivity of 1 dS/m; sodium absorption ratio is 17; averages 40 percent gravel and 5 percent cobbles; strongly effervescent (4 percent calcium carbonate equivalent); very strongly alkaline (pH 9.3).

TYPE LOCATION: San Bernardino County, California; approximately 1 mile northeast of Sand Hill and 1 mile northeast along Surprise Spring Road from southern military base boundary; about 100 feet east and 800 feet south of the northwest corner of section 16, T. 2 N., R. 7 E; 34 degrees, 15 minutes, 47.9 seconds north latitude and 116 degrees, 15 minutes, 48.7 seconds west longitude; Goat Mountain quadrangle; UTM 11S, 0567804e 3791400n; NAS-C.

RANGE IN CHARACTERISTICS:

Soil moisture - 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 - 68 to 71 degrees F.

Depth to the argillic - 4 to 14 inches.

Depth to duripan - 20 to 30 inches.

Particle-size control section - Clay content: Averages 18 to 35 percent.

A horizons - Value: 6 or 7 dry, 4 or 5 moist.

Chroma: 3 or 4.

Rock fragments: 0 to 15 percent.

Effervescence: Noneffervescent or slightly effervescent.

Calcium carbonate equivalent: 0 to 3 percent.

Btk1 horizon - Value: 5 or 6 dry, 4 or 5 moist.

Chroma: 4 or 5 dry, 3 or 4 moist.

Rock fragments: 0 to 15 percent.

Clay content: 12 to 20 percent.

Effervescence: Slightly effervescent or strongly effervescent.

Reaction: Moderately alkaline to strongly alkaline.

Calcium carbonate equivalent: 1 to 5 percent.

Btk2 horizon - Value: 5 or 6 dry, 4 or 5 moist.

Chroma: 4 or 5 dry, 3 or 4 moist.

Rock fragments: 0 to 15 percent.

Clay content: 20 to 35 percent.

Effervescence: Slightly effervescent or strongly effervescent.

Reaction: Moderately alkaline to strongly alkaline.

Calcium carbonate equivalent: 1 to 5 percent.

Bkq horizon - Value: 6 through 8 dry, 5 through 7 moist.

Chroma: 2 through 4.

Rock fragments: 0 to 15 percent gravel.

Calcium carbonate equivalent: 10 to 25 percent.

Bkqm horizon - Structure: Massive or platy.

Cementation: Very weakly or weakly cemented.

Bkq' horizon - Value: 6 through 8 dry, 5 through 7 moist.

Chroma: 2 through 4.

Rock fragments: 0 to 15 percent gravel.

Calcium carbonate equivalent: 10 to 20 percent.

Reaction: Strongly alkaline or very strongly alkaline.

Electrical conductivity: 0 to 2 dS/m.

Sodium absorption ratio: 5 to 12.

Ckqn horizon - Value: 6 through 8 dry, 5 through 7 moist.
Chroma: 2 through 4.

Rock fragments: 35 to 50 percent gravel, 0 to 5 percent cobbles.

Calcium carbonate equivalent: 1 to 5 percent.

Reaction: Strongly alkaline or very strongly alkaline.

Electrical conductivity: 0 to 2 dS/m.

Sodium absorption ratio: 13 to 30.

COMPETING SERIES: These are the Joshua (CA) and Strozi (NV) series. Joshua soils have a mean annual soil temperature of 63 to 67 degrees F. and have 15 to 35 percent gravels in the particle-size control section. Strozi series have a mean annual soil temperature of 63 to 67 degrees F.

GEOGRAPHIC SETTING: Desfirex soils are on fan remnants. These soils formed in sandy alluvium derived from granite. Elevations are 1,885 to 2,900 feet. Slopes are 2 to 4 percent. The climate is arid with hot, dry summers and warm, moist winters. The mean annual precipitation is 2 to 6 inches; the mean annual air temperature is 66 to 69 degrees F. and the frost free season is 240 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Calcio, Edalph and Narea soils. Calcio soils do not have duripans. Edalph and Narea soils do not have argillic horizons or duripans.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability above the pan and very rapid below.

USE AND VEGETATION: Military exercises and wildlife habitat. The present vegetation is mainly white bursage and creosotebush.

DISTRIBUTION AND EXTENT: Mojave desert of southeastern California, U.S.A.; MLRA 30. These soils are of small extent.

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

SERIES ESTABLISHED: San Bernardino County, California, Marine Corps Air/Ground Combat Center Soil Survey Area, 2000. The name is coined from the acronym for Desert Fire Exercises (Desfirex), an intense training cycle involving a series of progressive live fire exercises.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

1. Ochric epipedon -- 0 to 5 inches (A1 and A2 horizons).
2. Argillic horizon -- 5 to 23 inches (Btk1 and Btk2 horizons)
3. Duripan -- 28 to 32 inches (Bkqm horizon).
4. Particle-size control section -- 5 to 23 inches (Btk1 and Btk2 horizons).

Sampled by National Lab #S97CA-071-004

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 6/2000. ET

National Cooperative Soil Survey
U.S.A.