LOCATION PONYSPRING NVEstablished Series
TAXONOMIC CLASS: Ashy, glassy, mesic Vitritorrandic Argixerolls
TYPICAL PEDON: Ponyspring gravelly ashy loamy coarse sand, rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with approximately 40 percent pebbles; lithology of fragments is welded tuff.
A1--0 to 2 inches; brown (10YR 5/3) gravelly ashy loamy coarse sand, dark brown (10YR 3/3) moist; weak medium granular structure; soft, very friable, slightly sticky and nonplastic; few very fine and fine roots; few very fine and fine irregular and tubular pores; 25 percent pebbles and 5 percent cobbles; neutral (pH 7.0); clear smooth boundary. (2 to 6 inches thick)
A2--2 to 6 inches; dark grayish brown (10YR 4/2) gravelly ashy sandy loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few very fine, common fine and few medium roots; few very fine and fine irregular and tubular pores; 15 percent pebbles and 5 percent cobbles; neutral (pH 7.2); clear smooth boundary. (0 to 7 inches thick)
Btk1--6 to 12 inches; brown (10YR 5/3) cobbly ashy sandy clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine, common fine and medium roots; common fine and medium irregular and tubular pores; common distinct clay films on faces of peds; 15 percent pebbles and 15 percent cobbles; few (2 percent) distinct secondary calcium carbonate concretions on bottom of rock fragments; neutral (pH 7.0); clear smooth boundary. (3 to 12 inches thick)
Btk2--12 to 20 inches; yellowish brown (10YR 5/4) gravelly ashy sandy clay loam, dark yellowish brown (10YR 3/4) moist; strong coarse subangular blocky structure; very hard, very firm, moderately sticky and moderately plastic; few very fine, common fine and medium roots; common fine and medium irregular and tubular pores; many distinct clay films on faces of peds and lining pores; 15 percent pebbles; common (5 percent) distinct secondary calcium carbonate concretions around rock fragments; neutral (pH 7.2); clear smooth boundary.
Btk3--20 to 30 inches; yellowish brown (10YR 5/4) gravelly ashy sandy loam, dark yellowish brown (10YR 3/4) moist; strong coarse subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine, common fine and few medium roots; common very fine and fine irregular and tubular pores; common faint clay films on faces of peds; 20 percent pebbles; common (5 percent) distinct secondary calcium carbonate concretions around rock fragments; slightly alkaline (pH 7.5); clear smooth boundary. (Combined thickness of the Btk2 and Btk3 horizons is 16 to 24 inches)
Btqk1--30 to 46 inches; yellowish brown (10YR 5/4) ashy clay loam, dark yellowish brown (10YR 4/4) moist; strong coarse subangular blocky structure parting to moderate medium subangular blocky; hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; few very fine irregular pores; common distinct clay films on faces of peds and coating sand grains; 10 percent pebbles and 1 percent cobbles; common (10 percent) distinct secondary calcium carbonate and secondary silica concretions around rock fragments and common (10 percent) secondary calcium carbonate masses and fine threads; slightly effervescent; slightly alkaline (pH 7.5); clear smooth boundary. (10 to 20 inches thick)
Btqk2--46 to 60 inches; light yellowish brown (10YR 6/4) gravelly ashy coarse sandy loam, dark yellowish brown (10YR 4/4) moist; massive; hard, firm, moderately sticky and moderately plastic; few very fine roots; few very fine irregular pores; common distinct clay films on faces of peds and bridging sand grains; 15 percent pebbles and 2 percent cobbles; common (10 percent) distinct secondary calcium carbonate and secondary silica concretions around rock fragments and secondary calcium carbonate disseminated throughout; strongly effervescent; moderately alkaline (pH 8.1).
TYPE LOCATION: Lincoln County, Nevada; approximately 3 miles south of Pony Springs, 0.5 miles west of State Highway 93; about 1,200 feet north and 800 feet east of the southwest corner section 20, T. 5 N., R. 66 E.; USGS Pony Springs 7.5 minute topographic quadrangle; 38 degrees 16 minutes 29 seconds north latitude and 114 degrees 36 minutes 8 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist for short periods in winter and early spring and intermittently moist for 10 to 20 days cumulative from July through September due to convection storms. Aridic soil moisture regime bordering on xeric.
Soil temperature: 47 to 52 degrees F.
Thickness of the mollic epipedon: 10 to 14 inches and may include the upper part of the argillic horizon.
Depth to argillic horizon: 3 to 7 inches.
Depth to identifiable secondary calcium carbonate: 6 to 14 inches.
Mineralogy: 40 to 60 percent volcanic glass in the 0.2 to 2.0 millimeter fraction.
Control section - Clay content: 18 to 27 percent.
Rock fragments: 15 to 35 percent, mainly pebbles.
A horizons - Value: 4 or 5 dry.
Chroma: 2 or 3, dry or moist.
Structure: Weak or moderate granular or subangular blocky.
Btk horizons - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 through 4, dry or moist.
Texture: Gravelly ashy sandy loam, gravelly ashy clay loam, gravelly ashy sandy clay loam, or cobbly ashy sandy clay loam.
Clay content: 18 to 27 percent.
Rock fragments: 15 to 35 percent.
Structure: Moderate to strong, medium to coarse subangular blocky.
Secondary calcium carbonate: Faint to distinct concretions on bottom or around rock fragments.
Reaction: Neutral to slightly alkaline.
Btqk horizons - Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Gravelly ashy coarse sandy loam, ashy sandy clay loam, and ashy clay loam.
Clay content: 18 to 35 percent.
Rock fragments: 10 to 35 percent.
Structure: Massive or medium to coarse subangular blocky.
Reaction: Neutral to moderately alkaline.
Effervescence: Slightly effervescent to strongly effervescent.
Calcium carbonate equivalent: 1 to 5 percent in the material less than 2 mm.
COMPETING SERIES: These are the
Ashone(NV),
Bidwell(CA),
Coppersmith(T CA) and
Simpson(CA) series.
The Ashone soils are moderately deep to paralithic material, do not have secondary calcium carbonate in the profile and are not intermittently moist for 10 to 20 days cumulative from July to September due to convection storms. Bidwell soils have 0 to 10 percent rock fragments in the control section and are not intermittently moist for 10 to 20 days cumulative from July to September due to convection storms. Coppersmith soils contain 20 to 70 percent durinodes and are not intermittently moist for 10 to 20 days cumulative from July to September due to convection storms. Simpson soils have a mollic epipedon that is 20 to 27 inches thick and have 35 to 50 percent clay in the control section.
GEOGRAPHIC SETTING: Ponyspring soils are on fan remnants. These soils formed in alluvium derived from welded tuff. Slopes range from 0 to 15 percent. Elevations range from 5,400 to 7,500 feet. The mean annual temperature is 45 to 50 degrees F., mean annual precipitation is 12 to 14 inches and the frost-free period is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cath, Nevu, Okayview and Zoda series. Cath soils have a mean annual soil temperature of 53 to 58 degrees and contain a horizon with a firm and brittle matrix. Nevu soils are moderately deep to a duripan. Okayview soils are shallow to a paralithic contact. Zoda soils are moderately deep to a duripan.
DRAINAGE AND PERMEABILITY: Well drained; runoff is low to medium; permeability is moderate; saturated hydraulic conductivity class is moderately high or high.
USE AND VEGETATION: Livestock grazing and wildlife habitat. The potential native vegetation includes bluebunch wheatgrass, Thurbers needlegrass, muttongrass, basin wildrye, mountain big sagebrush and antelope bitterbrush. This pedon is correlated to Ecological Site R028AY092NV, Loamy 12-14 P.Z.
DISTRIBUTION AND EXTENT: South central Nevada. Ponyspring soils are not extensive. MLRA 28A and 29.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Lincoln County, Nevada, North Part; 2004. The name is from a spring in the area.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 12 inches (A1, A2 and Btk1 horizons).
Argillic horizon - The zone from 6 to 60 inches (Btk1, Btk2, Btk3, Btqk1 and Btqk2 horizons).
Particle-size control section - The zone from 6 to 26 inches (Btk1, Btk2 and the upper part of the Btk3 horizons).