LOCATION FRANKTOWN NV CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Ultic Haploxerolls
TYPICAL PEDON: Franktown very stony sandy loam--forest land. (Colors are for dry soil unless otherwise noted).
Oi--0 to 0.5 inches; slightly decomposed forest litter of pine needles; abrupt wavy boundary. (0 to 2 inches thick).
A--0.5 to 5 inches; olive gray (5Y 5/2) very stony sandy loam, dark olive gray (5Y 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine roots; many very fine interstitial pores; 60 percent rock fragments, predominantly stones; moderately acid (pH 6.0); clear smooth boundary. (4 to 16 inches thick)
C--5 to 10 inches; light olive gray (5Y 6/2) very gravelly sandy loam, olive gray (5Y 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine and few medium roots; many very fine interstitial pores; 60 percent gravel and some stones and cobbles; moderately acid (pH 6.0); abrupt irregular boundary. (0 to 10 inches thick)
R--10 to 14 inches; gray (N 5/0) extremely hard gneiss bedrock, very dark gray (N 3/0) moist.
TYPE LOCATION: Douglas County, Nevada; on the Toiyabe National Forest in the Carson Range about 1.5 miles northwest of Genoa; approximately 1,600 feet east and 700 feet south of the northwest corner of section 4, T. 13 N., R. 19 E.; USGS Genoa 7.5 minute topographic quadrangle; 39 degrees 01 minute 28 seconds north latitude and 119 degrees 51 minutes 24 seconds west longitude, NAD83; UTM zone 11N 252694E, 4323377N, NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in the moisture control section during late fall, winter, and spring; dry from July through early October for 75 to 90 consecutive days in the four months following the summer solstice; Xeric moisture regime that borders on aridic.
Mean annual soil temperature - 44 to 47 degrees F.
Mollic epipedon thickness - 4 to 16 inches; In some pedons includes 1 to 3 inches of the C horizon for a total of 7 inches, mixed.
Depth to bedrock - 4 to 20 inches to a lithic contact.
Particle-size control section - Clay content: Averages 5 to 10 percent; Rock fragments: Averages 50 to 80 percent, mainly gravel and cobbles. Lithology of rock fragments are metavolcanic rocks such as gneiss, schist, shale or metavolcanics.
A horizon - Hue: 10YR through 5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3 dry or moist.
Organic matter content: 2 or 3 percent.
Reaction: Moderately acid or slightly acid.
C horizon - Hue: 10YR through 5Y.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Very gravelly sandy loam, extremely gravelly coarse sandy loam, or very gravelly fine sandy loam.
Clay content: 12 to 18 percent.
Rock fragment content: 50 to 80 percent, mainly gravel or cobbles.
Organic matter content: 1 or 2 percent.
Reaction: Moderately acid or slightly acid.
Base saturation: Less than 60 percent.
COMPETING SERIES: These are the Baldknob, Blewett, Fivebit, Timgulch (T), and Wintercanyon series.
Baldknob soils have a cambic horizon and do not have a C horizon. Blewett soils do not have a C horizon. Fivebit soils have texture of clay loam, silty clay loam, or loam and do not have a C horizon. Timgulch soils have 15 to 20 percent clay in the particle-size control section. Wintercanyon soils have 10 to 18 percent clay in the particle-size control section and do not have a C horizon.
GEOGRAPHIC SETTING: Franktown soils are on mountains. They typically occur on backslope positions. Elevations range from 5,200 to 8,000 feet. Slopes are 45 to 80 percent. These soils formed in residuum and colluvium derived from metamorphic rocks such as gneiss, schist, slate, or metavolcanics. The climate is subhumid-continental with a mean annual precipitation of 16 to 30 inches. The mean annual temperature is 41 to 45 degrees F., the mean January temperature is about 38 degrees F., and the mean July temperature is about 65 degrees F. The frost-free period is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Genoa and Toiyabe soils. Genoa soils have argillic horizons. Toiyabe soils are sandy, shallow to weathered bedrock, and have ochric epipedons.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very high surface runoff; moderately rapid permeability (high saturated hydraulic conductivity).
USE AND VEGETATION: Franktown soils are used mainly for wildlife habitat and watershed. The vegetation is principally Jeffrey pine in small groves or as scattered trees with an understory of mountain big sagebrush, antelope bitterbrush, serviceberry, snowberry, bluegrass, needlegrass, buckwheat, and curlleaf mountainmahogany.
DISTRIBUTION AND EXTENT: Western Nevada and eastern California in the Sierra Nevada Range. Franktown soils are not extensive with about 3,000 acres of the series mapped to date. MLRA 22A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Douglas County (Carson Valley Area), Nevada, 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0.5 to 7.5 inches (A horizon and part of the C horizon).
Lithic contact - The boundary at 10 inches to underlying hard bedrock (R layer).
Particle-size control section - The zone from the soil surface to 10 inches (Oi, A, and C horizons).