LOCATION CORNCREEK               NV

Established Series
Rev. LJL/TM/RLB/ET
04/2015

CORNCREEK SERIES

The Corncreek series consists of very deep, well drained soils that formed in alluvium derived from limestone and dolomite over lacustrine deposits. Corncreek soils are on fan skirts. Slope ranges from 0 to 8 percent. The mean annual precipitation is about 150 millimeters (6 inches) and the mean annual air temperature is about 17 degrees C. (63 degrees F.).

TAXONOMIC CLASS: Loamy-skeletal, carbonatic, thermic Sodic Haplocalcids

TYPICAL PEDON: Corncreek extremely gravelly fine sandy loam - rangeland and wildlife habitat. Colors are for dry soil unless otherwise noted. The soil surface is covered by approximately 85 percent gravel.

A--0 to 3 centimeters (0 to 1 inch); light gray (10YR 7/2) extremely gravelly fine sandy loam, brown (10YR 5/3) moist; strong very thick platy structure; hard, very friable, slightly sticky and non-plastic; common very fine, fine and medium vesicular pores and few fine tubular pores; 70 percent gravel; violently effervescent (55 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.4); abrupt smooth boundary. (5 to 8 centimeters thick)

Btk--3 to 10 centimeters (1 to 4 inches); light gray (10YR 7/2) gravelly fine sandy loam, brown (10YR 5/3) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and non-plastic; common very fine, few fine and medium roots; few very fine and fine interstitial pores; common faint clay skins on ped faces and colloidal stains; common distinct calcium carbonate coats on undersides of rock fragments; 25 percent gravel; violently effervescent (35 percent calcium carbonate equivalent in the fine earth fraction); strongly alkaline (pH 8.6); clear wavy boundary. (5 to 13 centimeters thick)

C1--10 to 43 centimeters (4 to 17 inches); light gray (10YR 7/2) extremely gravelly sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, non-sticky and non-plastic; common very fine, fine and few medium roots; common very fine and fine interstitial pores; few distinct randomly oriented calcium carbonate coats on rock fragments; 65 percent gravel; violently effervescent (60 percent calcium carbonate equivalent in the fine earth fraction); strongly alkaline (pH 8.8); clear wavy boundary. (25 to 48 centimeters thick)

C2--43 to 79 centimeters (17 to 31 inches); light gray (10YR 7/2) extremely gravelly sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, non-sticky and non-plastic; common very fine, few fine and medium roots; common very fine and fine interstitial pores; few distinct randomly oriented calcium carbonate coats on rock fragments; 65 percent gravel; violently effervescent (60 percent calcium carbonate equivalent in the fine earth fraction); strongly alkaline (pH 8.8); abrupt wavy boundary. (18 to 38 centimeters thick)

2Bkn1--79 to 104 centimeters (31 to 41 inches); white (10YR 8/1) silt loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, very friable, slightly sticky and moderately plastic; few very fine through medium roots; common very fine, fine and few medium tubular pores; 10 percent gravel consisting of very strongly cemented calcium carbonate nodules; sodium absorption ratio 13; violently effervescent (90 percent calcium carbonate equivalent in the fine earth fraction); very strongly alkaline (pH 9.4); gradual wavy boundary. (20 to 30 centimeters thick)

2Bkn2--104 to 152 centimeters (41 to 60 inches); white (10YR 8/1) silt loam, light yellowish brown (10YR 6/4) moist; massive; very hard, friable, slightly sticky and slightly plastic; few fine and medium roots; common very fine through medium tubular pores; 10 percent gravel consisting of very strongly cemented calcium carbonate nodules; sodium absorption ratio 18; violently effervescent (80 percent calcium carbonate equivalent in the fine earth fraction); strongly alkaline (pH 9.0).

TYPE LOCATION: Clark County, Nevada; approximately 5.6 kilometers (3 1/2 miles) west northwest of Corn Creek Springs in the northwest end of Las Vegas Valley; about 363 meters (1,190 feet) south and 349 meters (1,145 feet) east of the northwest corner of sec. 30, T. 17 S., R. 59 E.; USGS Corn Creek Springs NW, NV 7.5 minute topographic quadrangle; 36 degrees, 27 minutes, 07 seconds north latitude and 115 degrees, 25 minutes, 11 seconds west longitude; UTM 11s, 641614e, 4035237n; NAD 83.

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 to October following convection storms. The soils have a typic-aridic soil moisture regime.

Soil temperature: 17 to 20 degrees C. (63 to 68 degrees F.).

Depth to unconformity and calcic horizon: 64 to 89 centimeters (25 to 35 inches).

Control section
Clay content: 8 to 18 percent. Rock fragments: averages 35 to 60 percent. Upper part has 60 to 75 percent, mainly limestone gravel and the lower part has 5 to 20 percent, very strongly cemented calcium carbonate nodules.
A horizon:
Value: 7 or 8 dry, 5 or 6 moist.
Calcium carbonate equivalent in the fine earth fraction: 30 to 60 percent.

Btk horizon:
Value: 7 or 8 dry, 5 or 6 moist.
Texture: fine sandy loam or very fine sandy loam.
Clay content: 8 to 18 percent.
Rock fragments: 5 to 25 percent, mainly gravel.
Structure: coarse or very coarse, subangular blocky or platy.
Consistence: slightly hard or hard, friable or very friable, non plastic or slightly plastic.
Reaction: Moderately alkaline or strongly alkaline.
C horizons:
Chroma: 2 through 4 dry, 3 or 4 moist.
Texture: Sandy loam or fine sandy loam.
Clay content: 8 to 18 percent.
Rock fragments: 60 to 75 percent, mainly gravel.
Structure: Medium or coarse.
Consistence: Soft or slightly hard.
Calcium carbonate equivalent in the fine earth fraction: 45 to 75 percent.
Sodicity (SAR): 1 through 5.
Other features: None to few very thin calcium carbonate coats randomly oriented on rock fragments in most pedons. 0 to 3 percent gravel size calcium carbonate nodules.

2Bkn horizons:
Value: 7 or 8 dry, 5 or 6 moist.
Chroma: 1 through 4.
Texture: Silt loam or loam.
Clay content: 10 to 18 percent.
Rock fragments: 5 to 20 percent, very strongly cemented calcium carbonate nodules.
Calcium carbonate equivalent in the fine earth fraction: 70 to 95 percent.
Reaction: Strongly alkaline or very strongly alkaline.
Sodicity (SAR): 13 through 30.
Other features: Greater than 5 percent very strongly cemented secondary calcium carbonate nodules and soft masses.

COMPETING SERIES: These are the Joemay (NV) and Oldspan (NV) series. Joemay soils average 60 to 75 percent rock fragments in the particle size control section and have a calcic horizon at 5 to 50 centimeters (2 to 20 inches). Oldspan soils have a calcic horizon at 13 to 30 centimeters (5 to 12 inches) and does not have lacustrine sediments.

GEOGRAPHIC SETTING: Corncreek soils are on fan skirts. These soils formed in alluvium derived from limestone and dolomite over lacustrine sediments. Slope ranges from 0 to 8 percent. Elevations are 840 to 1070 meters (2,760 to 3,500 feet). The climate is hot and arid with warm, moist winters and hot, dry summers. The mean annual precipitation is 125 to 178 millimeters (5 to 7 inches); mean annual air temperature is 16 to 18 degrees C. (60 to 65 degrees F.), and the frost-free season is 200 to 260 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pahrump series. Pahrump soils have 35 to 60 percent indurated calcium carbonate nodules that make it loamy-skeletal.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very low runoff; moderate permeability; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly white bursage, shadscale and creosotebush.

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada; MLRA 30. These soils are moderately extensive.

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

SERIES ESTABLISHED: Clark County Area, Nevada, 2006. The name is coined from Corn Creek Spring which is located nearby.

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

Ochric epipedon - 0 to 10 centimeters (0 to 4 inches) (A and 2Bkn1 horizons).
Calcic horizon - 79 to 152 centimeters (31 to 60 inches) (2Bkn1 and 2Bkn2 horizons).
Particle-size control section - 25 to 100 centimeters (10 to 40 inches) (Part of C1 horizon, C2 horizon and part of 2Bkn1).

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 6/2011. ET

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National Cooperative Soil Survey
U.S.A.