LOCATION ORICTO                  NV

Established Series
Rev. JHD/WED/JBF
05/2016

ORICTO SERIES

The Oricto series consists of very deep, well drained soils that formed in mixed alluvium derived from rhyolite, andesite and granodiorite. Oricto soils are on fan remnants, fan piedmonts and beach plains. Slopes are 0 to 30 percent. The mean annual precipitation is about 100 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Typic Calciargids

TYPICAL PEDON: Oricto very gravelly fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 8 cm; pale brown (10YR 6/3) very gravelly fine sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; few fine and very fine roots; many very fine and fine vesicular pores; 35 percent gravel and 15 percent cobbles; slightly effervescent; strongly alkaline (pH 8.5); abrupt wavy boundary. (3 to 10 cm thick)

Bt--8 to 20 cm; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; moderate coarse and medium subangular blocky structure; soft, very friable; slightly sticky and slightly plastic; few medium, common very fine and fine roots; common very fine tubular pores; 40 percent gravel and 15 percent cobbles; few faint clay films on faces of peds, many faint clay films in pores; violently effervescent; very strongly alkaline (pH 9.2); abrupt wavy boundary. (8 to 24 cm thick)

Bk--20 to 36 cm; pale brown (10YR 6/3) extremely gravelly sandy loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; few very fine and fine roots; few very fine and fine tubular pores; 40 percent gravel and 25 percent cobbles; common distinct carbonate pedants on rock fragments; violently effervescent; very strongly alkaline (pH 9.6); abrupt smooth boundary. (8 to 30 cm thick)

2C--36 to 66 cm; pale brown (10YR 6/3) extremely gravelly sand, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine and fine interstitial pores; 60 percent gravel and 5 percent cobbles; violently effervescent; very strongly alkaline (pH 9.6); abrupt smooth boundary. (0 to 50 cm thick)

3C--66 to 94 cm; pale brown (10YR 6/3) very gravelly loamy sand, brown (10YR 5/3) moist; massive; soft, very friable; nonsticky and nonplastic; few very fine and fine roots; common very fine and fine interstitial pores; 35 percent gravel; strongly effervescent; very strongly alkaline (pH 9.2); clear smooth boundary. (0 to 84 cm thick)

4C--94 to 152 cm; pale brown (10YR 6/3) extremely gravelly coarse sand, brown (10YR 5/3) moist; massive, soft, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine and fine interstitial pores; 60 percent gravel and 5 percent cobbles; violently effervescent; strongly alkaline (pH 9.0).

TYPE LOCATION: Mineral County, Nevada, about 1/4 mile north of the old Placer mine; about 2,100 feet south and 500 feet west of the northeast corner of section 23, T. 13 N., R. 33 E.; USGS Murphys Well, NV 7.5 minute topographic quadrangle; latitude 38 degrees 58 minutes 43 seconds N and longitude 118 degrees 17 minutes 09 seconds W; WGS84 Decimal Degrees 38.9786111 latitude, -118.219167 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in some part for short periods during winter and early spring months and for 10 to 20 days cumulative between July and October due to convective storms. Dry in lower moisture control section, typic aridic moisture regime.
Mean annual soil temperature: 13 to 15 degrees C.
Reaction: Strongly alkaline or very strongly alkaline. Sandy surface layer may be moderately alkaline.
Depth to 2C horizon: 23 to 48 cm.
Depth to bottom of Bt horizon: 15 to 23 cm.

Particle-size control section - Clay content: Averages 2 to 6 percent.
Rock fragments: Averages 35 to 60 percent, mainly gravel.

A horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.
Effervescence: Slightly effervescent through violently effervescent.

Bt horizon
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 3 or 4.
Rock fragments: Average 35 to 55 percent
Texture: Loam or sandy clay loam.
Clay content: 20 to 27 percent.
Structure: Prismatic or subangular blocky.
Consistence: Soft to hard, very friable to firm, slightly sticky to sticky and slightly plastic to plastic.
Effervescence: Strongly effervescent or violently effervescent.
Sodicity (SAR): 13 to 45.

Bk horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.
Texture: Sandy loam or coarse sandy loam.
Rock fragments: 35 to 70 percent.
Structure: Massive or subangular blocky.
Consistence: Nonplastic to slightly plastic.
Effervescence: Strongly effervescent or violently effervescent.

C horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 1 through 3.
Rock fragments: 35 to 70 percent.
Texture: Stratified coarse sand and loamy sand.
Sodicity (SAR): 13 to 90.
Consistence: Soft to hard dry, very friable to firm, nonsticky to slightly sticky and nonplastic to slightly plastic.
Effervescence: Slightly effervescent through violently effervescent.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Oricto soils are on fan pediments, beach plains and fan remnants. These soils formed in mixed alluvium derived from rhyolite, andesite and granodiorite. Elevations are 1,091 to 1,820 meters. Slopes are 0 to 30 percent. The climate is cool, and arid with an average annual temperature of 12 to 14 degrees C, mean annual precipitation is 75 to 150 mm and the average frost free season is 130 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Annaw and Izo soils. Annaw soils have a cambic horizon and are on remnant side slopes and inset alluvial fan surfaces. Izo soils lack an argillic horizon.

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

USE AND VEGETATION: Rangeland and wildlife habitat. The vegetation is principally shadscale, and Cooper wolfberry with less than 10 percent canopy cover.

DISTRIBUTION AND EXTENT: Central Nevada. The soils are of small extent. MLRA 27 and 29.

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

SERIES ESTABLISHED: Esmeralda County, Nevada, 1984.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface to 8 cm (A horizon).
Argillic horizon - The zone from 8 to 20 cm (Bt horizon).
Calcic horizon - The zone from 20 to 36 cm (Bk horizon).
Particle size control section - The zone from 25 to 100 cm (2C, 3C and parts of the Bk and 4C horizons).

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National Cooperative Soil Survey
U.S.A.