LOCATION CATBOB CA

Tentative Series
IRD: GMW/LJL/CAH/ET
04/2015

CATBOB SERIES

The Catbob series consist of deep, well drained soils that formed in residuum derived from metamorphic rocks. Catbob soils are on low hills. Slopes range from 2 to 15 percent. The mean annual precipitation is about 150 millimeters (6 inches) and the mean annual temperature is 18.5 C (65 degrees F).

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Typic Haplargids

TYPICAL PEDON: Catbob loamy sand, on an 8 percent slope under desert shrubs at an elevation of 1,166 meters (3,825 feet). (Colors are for dry soils unless otherwise noted.) The soil surface is covered by approximately 10 percent fine gravel and 30 percent medium and coarse gravel.

A -- 0 to 3 centimeters (0 to 1 inch); brown (10YR 5/3) loamy sand, dark brown (10YR 3/3) moist; moderate thick platy structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; common very fine tubular and vesicular pores; 4 percent fine gravel and 1 percent medium and coarse gravel; neutral (pH 6.7); abrupt smooth boundary. (2 to 5 centimeters thick)

Bt1 -- 3 to 13 centimeters (1 to 5 inches); dark yellowish brown (10YR 4/4) sandy loam, dark yellowish brown (10YR 3/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine irregular pores; 5 percent faint, dark yellowish brown (10YR 3/4), clay films bridging sand grains and 10 percent dark yellowish brown (10YR 3/4), clay films on rock fragments; 7 percent fine gravel and 3 percent medium and coarse gravel; neutral (pH 6.7); clear wavy boundary. (8 to 13 centimeters thick)

Bt2 -- 13 to 42 centimeters (5 to 17 inches); dark yellowish brown (10YR 4/4) gravelly loamy sand, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; 10 percent faint, dark yellowish brown (10YR 3/4), clay films bridging sand grains and 5 percent dark yellowish brown (10YR 3/4), clay films along fractures; 15 percent fine gravel; neutral (pH 6.8); clear wavy boundary. (29 to 47 centimeters thick)

C -- 42 to 110 centimeters (17 to 43 inches); brown (10YR 5/3) gravelly coarse sand, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and few fine and medium roots in cracks; 25 percent fine gravel and 5 percent medium and coarse gravel; neutral (pH 6.8); gradual irregular boundary. (40 to 68 centimeters thick)

Cr -- 110 to 163 centimeters (40 to 64 inches); hard, moderately weathered, fractured metamorphic rock, with fractures greater than 10 centimeters apart; very high excavation difficulty.

TYPE LOCATION: San Bernardino County, California; approximately 7.5 kilometers southwest of the intersection of Ivanpah Road and Cedar Canyon Road; 125 meters (410 feet) east and 10 meters (35 feet) north of the southwest corner of section 24, T. 12 N., R. 17 E., San Bernardino Baseline and Meridian; 35 degrees, 5 minutes, and 57.1 seconds north latitude, and 115 degrees, 6 minutes, and 29.7 seconds west longitude; USGS Signal Hill 7.5 minute topographic quadrangle; UTM 11S 0672426e 3885682n (DATUM: NAD83).

RANGE IN CHARACTERISTICS:
Soil moisture control section: usually dry, moist in some part 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: 19 to 22 degrees C (66 to 72 degrees F).
Surface rock fragments: range from 40 to 70 percent with 5 to 20 percent fine gravel, 30 to 50 percent medium and coarse gravel, and 0 to 5 percent cobbles.

Control section
Rock fragments: averages 10 to 35 percent gravel.
Clay content: averages 8 to 14 percent clay.
Depth to argillic horizon: 2 to 5 centimeters (1 to 2 inches).
Depth to base of argillic horizon: 10 to 25 centimeters (4 to 10 inches).
Depth to paralithic contact: 100 to 150 centimeters (40 to 59 inches).

A horizon
Hue: 2.5Y or 10YR.
Chroma: 3 or 4 moist.
Clay content: 5 to 8 percent.
Rock fragments: 0 to 15 percent gravel.
Reaction: slightly acid to neutral.

Bt horizons
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry; 3 to 5 moist.
Chroma: 4 or 6 moist.
Texture of the fine earth: loamy sand or sandy loam.
Clay content: 8 to 16 percent.
Rock fragments: 5 to 30 percent, gravel.
Reaction: slightly acid to neutral

C horizon
Hue: 2.5Y or 10YR.
Value: 3 or 4 moist.
Texture of the fine earth: coarse sand or sand.
Clay content: 2 to 3 percent.
Rock fragments: 15 to 30 percent gravel.

COMPETING SERIES: These are the Dovecanyon (CA), Friedliver (CA), Goldivide (CA), Goldpeak (CA), Helendale (CA), Hexie (CA), Jumborox (CA), Littlefargo (CA), Searchlight (NV), Sonoita (AZ+NM), Tray (CA), and Wingap (CA). The Dovecanyon, Friedliver, Goldivide, Goldpeak, Helendale, Jumborox, Searchlight, Sonoita, and tray soils are all very deep soils and do not have a paralithic contact within 150 centimeters, and are formed mainly in alluvium. Hexie and Littlefargo are moderately deep to a paralithic contact. In addition Sonoita soils are moist greater than 20 days cumulative in some part of the soil moisture control section following summer convection storms. Friedliver soils have an upper boundary of the argillic horizon between 25 and 50 centimeters, and Goldivid within 50 to 100 centimeters. Tray soils are strongly to very strongly alkaline in all parts and have an argillic horizon with an ESP of 15 to 30. Wingap soils have a mean annual soil temperature of 15 to 19 degrees C.

GEOGRAPHIC SETTING: Catbob soils are on low hills. Slopes range from 2 to 15 percent. These soils formed in residuum derived from metamorphic rocks. Elevations range from 1,000 to 1,250 meters (3,280 to 4,100 feet). The climate is arid with hot, dry summers and warm, moist winters. The mean annual precipitation is 125 to 175 millimeters (5 to 7 inches); mean annual air temperature is 17 to 20 degrees C. (62 to 68 degrees F.), and the frost-free season is 270 to 320 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Hexie soil. Hexie soils are moderately deep to a paralithic contact.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high saturated hydraulic conductivity above the bedrock and moderately high saturated hydraulic conductivity within the bedrock.

USE AND VEGETATION: These soils are used for recreation and wildlife habitat. The present vegetation is mainly Cooper's goldenbush, eastern Mojave buckwheat, and Nevada jointfir.

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 PROPOSED: San Bernardino County, California; Soil Survey of the Mojave National Preserve Area, California, 2012. This name is coined from the Bobcat Hills.

REMARKS: Diagnostic horizons and features in this pedon include:
Ochric epipedon - from a depth of 0 to 3 centimeters (A horizon).
Argillic horizon - from a depth of 3 to 42 centimeters (Bt1 and Bt2 horizons).
Paralithic contact - the zone beginning at 110 centimeters (Cr horizon).
Particle-size control section - from a depth of 3 to 42 centimeters (Bt1 and Bt2 horizons).

ADDITIONAL DATA: NASIS Pedon User ID: 2012CA795501.

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 10/2012. ET

National Cooperative Soil Survey
U.S.A.