LOCATION LAZAN NVEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic, shallow Xeric Torriorthents
TYPICAL PEDON: Lazan very gravelly coarse sand--forestland. (Colors are for dry soil unless otherwise noted.) The surface is covered by approximately 60 percent pebbles, 5 percent cobbles, and 1 percent stones.
A1--0 to 1 inch; pale brown (10YR 6/3) very gravelly coarse sand, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; 50 percent pebbles; neutral (pH 7.0); clear smooth boundary. (1 to 4 inches thick)
A2--1 to 4 inches; pale brown (10YR 6/3) very gravelly loamy coarse sand, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; 50 percent pebbles; neutral (pH 6.8); clear wavy boundary. (3 to 8 inches thick)
Cr--4 inches; highly fractured granitic rock.
TYPE LOCATION: Mineral County, Nevada; in the Wassuk Range northwest of Willow Canyon; approximately 1,000 feet south and 2,400 feet east of the northwest corner of section 32, T. 7 N., R. 30 E.; USGS Lucky Boy 7.5 minute topographic quadrangle; 38 degrees 25 minutes 38 seconds north latitude and 118 degrees 39 minutes 26 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in winter and spring, dry in summer and fall except for 10 to 20 days cumulative in some part between July and October due to convection storms; aridic (torric) moisture regime that borders on xeric.
Mean annual soil temperature - 47 to 53 degrees F.
Ochric epipedon thickness - 4 to 10 inches.
Depth to bedrock - 4 or 10 inches to a paralithic contact. The paralithic materials below the contact are weathered granitic rocks such as granite or granodiorite.
Particle-size control section - Clay content: Averages 6 to 10 percent; Rock fragments: 35 to 60 percent, mainly fine (2 to 5 millimeter) gravel. Lithology of fragments are granitic rocks such as granite or granodiorite.
Reaction - Neutral through slightly alkaline.
Effervescence - Noneffervescent or slightly effervescent.
A horizons - Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 through 4, dry or moist.
Texture: Very gravelly coarse sand or very gravelly loamy coarse sand; some pedons have thin A1 horizons of gravelly loamy sand or very gravelly coarse sandy loam.
Structure: Single grain or weak subangular blocky.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Lazan soils are on mountains and rock pediments. They typically occur on all slope positions, but usually have a south-facing aspect. These soils formed in residuum and colluvium from granitic rock. Slopes are 8 to 75 percent. Elevations range from 5,400 to 8,800 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 12 to 14 inches, mean annual temperature is 45 to 50 degrees F., and the frost-free period is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nupart and Rockabin soils. Nupart soils have mollic epipedons and a frigid temperature regime. Rockabin soils have mollic epipedons and are moderately deep to paralithic contacts.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very low or low surface runoff; very rapid permeability.
USE AND VEGETATION: Lazan soils are used for forestland and wildlife habitat. The present vegetation is a forest canopy of singleleaf pinyon with an understory of green ephedra, Wyoming big sagebrush, desert needlegrass, bottlebrush squirreltail, and antelope bitterbrush.
DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. The series concept and main acreage is in MLRA 26, while other acreage occurs in MLRA 29.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Esmeralda County, Nevada, 1984.
REMARKS: This revision of October 2002 updates the taxonomic class, from Sandy-skeletal, mixed, mesic, shallow Typic Xerorthents, because of a change in concept for moisture regime.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 4 inches (A1 and A2 horizons).
Paralithic contact - The boundary at 4 inches to underlying weathered, fractured bedrock (Cr layer).
Particle-size control section - The zone from the soil surface to 4 inches (A1 and A2 horizons).