LOCATION OJAVAN                  UT

Tentative Series
Rev. KWC
07/2022

OJAVAN SERIES

The Ojavan series consists of shallow, somewhat excessively drained soils that formed in slope alluvium derived from sandstone. Ojavan soils are on escarpments and structural benches. Slopes range from 15 to 70 percent. Mean annual precipitation is about 15 inches (381mm) and the mean annual temperature is about 48 degrees F (8.9 degrees C).

TAXONOMIC CLASS: Sandy-skeletal, siliceous, mesic Aridic Lithic Ustorthents

TYPICAL PEDON: Ojavan loamy fine sand - rangeland (Colors are for dry soil unless otherwise noted.)

CA--0 to 5 centimeters; yellowish brown (10YR 5/4) gravelly loamy fine sand, very pale brown (10YR 7/4), dry; 85 percent sand; 11 percent silt; 4 percent clay; moderate very thin platy structure parts to weak fine subangular blocky structure; very friable, soft, nonsticky, nonplastic; low excavation difficulty; common fine and very fine roots; 10 percent cobble and 25 percent gravel; noneffervescent, by HCl, 1 normal; slightly acid, pH 6.2; abrupt smooth boundary.

C--5 to 41 centimeters; yellowish brown (10YR 5/4) gravelly loamy fine sand, very pale brown (10YR 7/4), dry; 87 percent sand; 10 percent silt; 3 percent clay; structureless single grain structure; loose, loose, nonsticky, nonplastic; low excavation difficulty; common fine and very fine roots; 10 percent cobble and 25 percent gravel; noneffervescent, by HCl, 1 normal; slightly acid, pH 6.2; abrupt smooth boundary.

R--41 to 66 centimeters; sandstone bedrock.

TYPE LOCATION: Zion National Park, Kane County, Utah; lat. 37 degrees 14 minutes 40.32 seconds N. and long. 112 degrees 52 minutes 23.49 seconds W., UTM Zone: 12N, Northing 4123644, Easting 333858. WGS84

RANGE IN CHARACTERISTICS:

Soil moisture: aridic ustic moisture regime.

AC or CA horizon
Hue: 5YR, 7.5YR, 10YR
Value: 6 or 7 dry, 5 moist
Chroma: 3 or 4, dry or moist
Texture: fine sand, loamy fine sand
Clay content: 2 to 8 percent
Calcium carbonate equivalent: 0 to 1 percent
Electrical conductivity: 0 to 2 mmhos/cm
Rock fragments: 15 to 50 percent
Reaction: slightly acid to neutral (6.1 to 7.3)

C horizon
Hue: 5YR, 7.5YR, 10YR
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 3 or 4, dry or moist
Texture: fine sand, loamy fine sand
Clay content: 2 to 8 percent
Calcium carbonate equivalent: 0 to 1 percent
Electrical conductivity: 0 to 2 mmhos/cm
Rock fragments: 15 to 50 percent
Reaction: slightly acid to neutral (6.1 to 7.3)

COMPETING SERIES: These are the Wheels (AZ) series. Wheels series have thermic temperature regime, mixed mineralogy and is moderately alkaline.

GEOGRAPHIC SETTING: Ojavan soils are mapped on footslopes and toeslopes of sandstone escarpments.
Parent material: slope alluvium derived from sandstone
Landform: escarpments and structural benches
Slopes: 15 to 70 percent
Elevation: 5600 to 6190 feet (1700 to 1875 m)
Mean annual temperature: 45 to 51 degrees F (7.2 to 10.6 degrees C)
Mean annual precipitation: 14 to 16 inches (350 to 406 mm)
Precipitation pattern: May and June are the driest, January to March are the wettest, and monsoonal storms in late summer.
Frost-free period: 120 to 150 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Parkwash (UT), Pinepoint (UT) series. The Parkwash soils are on escarpments and structural benches. Parkwash soils lack rock fragments and are eolian deposits. The Pinepoint soils are on structural benches with low slopes and are very deep eolian deposit with no rock fragments.

DRAINAGE AND PERMEABILITY: somewhat excessively drained, high runoff, rapid to very rapid permeability.

USE AND VEGETATION: Ojavan soils are used for wildlife habitat. Vegetation includes Blue and Sideoats grama, Needle and Thread grass, Cheatgrass, Utah Juniper, Pinyon Pine, Ponderosa Pine, Utah Serviceberry, Yucca, Prickly Pear Cactus, Manzanita, Ephedra.

DISTRIBUTION AND EXTENT: Southern Utah; LRR D, MLRA 35; this soil series is of limited extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Phoenix, Arizona

SERIES PROPOSED: Zion National Park, Utah, soil survey area UT690.

The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Twelfth Edition, 2014

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National Cooperative Soil Survey
U.S.A.