LOCATION CAGAS                   NV

Established Series
Rev. BAL/RLB/JBF
11/2016

CAGAS SERIES

The Cagas series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from andesite, and welded tuff. The Cagas soils are on mountains and mountain ridges. Slopes are 15 to 50 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid Vitritorrandic Argixerolls

TYPICAL PEDON: Cagas extremely cobbly ashy sandy loam--woodland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with approximately 20 percent gravel, 40 percent cobbles, and 10 percent stones.

A1--0 to 8 cm; dark grayish brown (10YR 4/2) extremely cobbly ashy sandy loam, very dark grayish brown (10YR 3/2) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; 20 percent gravel, 40 percent cobbles, and 10 percent stones; neutral (pH 6.6); clear smooth boundary. (5 to 10 cm thick)

A2--8 to 13 cm; brown (10YR 5/3) extremely cobbly ashy sandy loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and common medium roots; many very fine and fine tubular and interstitial pores; 20 percent gravel, 40 percent cobbles, and 10 percent stones; neutral (pH 6.8); clear smooth boundary. (0 to 25 cm thick)

ABt--13 to 30 cm; brown (10YR 5/3) extremely cobbly ashy sandy loam, dark brown (10YR 3/3) moist; strong fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many very fine and fine tubular and interstitial pores; few faint clay films on faces of peds; 30 percent gravel and 30 percent cobbles; neutral (pH 7.0); clear smooth boundary. (13 to 25 cm thick)

Bt--30 to 48 cm; pale brown (10YR 6/3) extremely cobbly ashy sandy clay loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; common very fine, fine and medium roots; many very fine and fine tubular and interstitial pores; few faint clay films on faces of peds; 30 percent gravel and 30 percent cobbles; neutral (pH 7.0); clear smooth boundary. (13 to 25 cm thick)

C--48 to 69 cm; pale brown (10YR 6/3) extremely cobbly ashy sandy loam, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine, fine and medium roots; many very fine and fine interstitial pores; 20 percent gravel, 45 percent cobbles, and 2 percent stones; neutral (pH 7.0); abrupt irregular boundary. (19 to 49 cm thick)

2Cr--69 cm; soft, weathered tuff.

TYPE LOCATION: Lincoln County, Nevada; approximately 15 miles northwest of Atlanta, 1,700 feet south and 900 feet east of the northwest corner of section 16 T. 9 N., R. 67 E.; USGS Indian Springs Knolls 7.5 minute topographic quadrangle; 38 degrees latitude 38 minutes 38 seconds N and longitude 114 degrees 28 minutes 13 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist for short periods in winter and spring, dry in summer and fall and intermittently moist for 10 to 20 days cumulative between July and September due to convection storms; xeric bordering aridic soil moisture regime.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 36 cm, includes all or part of the AB horizon.
Depth to paralithic contact: 50 to 100 cm.
Reaction: Neutral or slightly alkaline.
Minerology: 30 to 50 percent volcanic glass in the 0.02 to 2.0 mm fraction, mainly weathered from the parent material.

Particle-size control section - Clay content: Averages 18 to 30 percent.
Rock fragments: 60 to 85 percent, mostly cobbles.

A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.

AB horizon
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Texture: Sandy loam or loam.
Clay content: 10 to 18 percent
Rock fragments: 60 to 85 percent.

Bt horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Sandy clay loam or loam.
Clay Content: 20 to 35 percent.
Rock fragments: 60 to 85 percent.

C horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 10 to 18 percent.
Rock fragments: 60 to 85 percent, mainly cobbles.

COMPETING SERIES: These are the Cabinspring, Derallo, Glassbutte , Jacksplace, Roughridge, and Slockey series.

Cabinspring soils do not receive appreciable summer moisture and have lithic contacts. Derallo soils do not receive appreciable summer moisture and are deep. Glassbutte and Roughridge soils do not receive appreciable summer moisture and are very deep. Jacksplace soils do not receive appreciable summer moisture and are moderately deep to lithic contacts. Slockey soils have lithic contacts and do not have C horizons.

GEOGRAPHIC SETTING: Cagas soils are on shoulders and backslopes of mountains and mountain ridges. These soils formed in residuum and colluvium derived from andesite and welded tuff. Slopes are 15 to 50 percent. Elevations are 1,830 to 2.595 meters. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 300 to 400 mm, mean annual temperature is 6 to 7 degrees C, and the frost-free season is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anaud and Nuhelen soils. Anaud soils have bedrock at 36 to 50 cm and Nuhelen soils have bedrock at 18 to 46 cm and have an average soil temperature of 8 to 12 degrees C.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, medium or very high runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Cagas soils are used for woodland and wildlife habitat. The potential native vegetation is mainly singleleaf pinion, mountain big sagebrush, mutton grass, and antelope bitterbrush. This pedon is correlated to Ecological Site F028AY076NV, Pinyon and mountain big sagebrush.

DISTRIBUTION AND EXTENT: Eastern Nevada. These soils are not extensive. MLRA 28A.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Lincoln County, Nevada, North Part; 1992. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 30 cm (A1, A2, and AB horizons).
Argillic horizon - The zone from 13 to 48 cm (ABt and Bt horizons).
Paralithic contact - The zone at 69 cm (2Cr horizon).
Particle-size control section - The zone from 30 to 48 cm (Bt horizon).

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National Cooperative Soil Survey
U.S.A.