LOCATION PIMOGRAN CA+NVEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid, shallow Entic Haploxerolls
TYPICAL PEDON: Pimogran very gravelly loamy coarse sand--forest land. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 35 percent gravel, 10 percent cobbles, 10 percent stones, and 10 percent boulders.
A1--0 to 2 inches; grayish brown (10YR 5/2) very gravelly loamy coarse sand, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; many very fine interstitial pores; 35 percent gravel and 10 percent cobbles; slightly acid; clear wavy boundary. (1 to 3 inches thick)
A2--2 to 10 inches; brown (10YR 5/3) very gravelly loamy coarse sand, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, common fine, and common medium roots; many very fine interstitial pores; 50 percent gravel and 5 percent cobbles; slightly acid; clear wavy boundary. (7 to 11 inches thick)
C1--10 to 14 inches; light brownish gray (10YR 6/2) very gravelly coarse sand, dark grayish brown (10YR 4/2) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and few fine roots; many very fine interstitial and few very fine tubular pores; 45 percent gravel and 5 percent cobbles; 10 percent paragravel; slightly acid; clear wavy boundary. (3 to 8 inches thick)
C2--14 to 18 inches; light gray (10YR 7/2) very gravelly coarse sand, grayish brown (10YR 5/2) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine tubular and interstitial pores; 50 percent gravel and 5 percent cobbles; 10 percent paragravel; slightly acid; clear irregular boundary. (3 to 5 inches thick)
Cr--18 to 28 inches; weathered and fractured granitic rock; few roots in fractures.
TYPE LOCATION: Mono County, California; on the Toiyabe National Forest about 0.5 mile northeast of Shingle Mill Flat; approximately 2,150 feet south and 900 feet east of the northwest corner of section 15, T. 7 N., R. 23 E.; USGS Chris Flat 7.5 minute topographic quadrangle; 38 degrees 27 minutes 10.0 seconds north latitude and 119 degrees 26 minutes 42.6 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in the moisture control section during late fall, winter, and spring; dry from July through early October; Xeric moisture regime.
Mean annual soil temperature - 44 to 47 degrees F.
Mollic epipedon thickness - 10 to 14 inches.
Depth to bedrock - 14 to 20 inches to a paralithic contact. The paralithic materials below the contact are weathered granitic rocks such as granodiorite.
Particle-size control section - Clay content: Averages 3 to 8 percent; Rock fragments: Averages 35 to 60 percent, mainly fine gravel (2 to 5 mm diameter). Lithology of fragments are granitic rocks such as granodiorite.
A horizons - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 1 to 3 percent.
Reaction: Slightly acid or neutral.
C horizons - Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Very gravelly coarse sand or very gravelly loamy coarse sand.
Clay content: 3 to 8 percent.
Rock fragments: 35 to 60 percent.
Pararock fragments: 5 to 15 percent paragravel
Reaction: Slightly acid or neutral.
COMPETING SERIES: This is the Granhogany series. Granhogany soils have mollic epipedons 14 to 20 inches thick.
GEOGRAPHIC SETTING: Pimogran soils are on mountains. They typically occur on backslope positions. They formed in residuum and colluvium derived from granitic rock. Slopes are 15 to 75 percent. Elevations range from 5,800 to 8,000 feet. The climate is subhumid-continental with cold, moist winters and warm, dry summers. The mean annual precipitation is 14 to 24 inches, the mean annual temperature is 39 to 45 degrees F., and the frost-free period is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Granhogany soil and the Elaero, Lockgate, and Toejom soils. Elaero soils have argillic horizons and are moderately deep to paralithic contacts. Lockgate soils have thick mollic epipedons, argillic horizons, and are deep to paralithic contacts. Toejom soils have ochric epipedons.
DRAINAGE AND PERMEABILITY: Excessively drained; high surface runoff; very rapid permeability (very high saturated hydraulic conductivity).
USE AND VEGETATION: Pimogran soils are used for forest land, recreation, watershed, and wildlife habitat. The native vegetation is mainly a forest canopy of singleleaf pinyon with an understory of curl-leaf mountain mahogany, snowberry, currant, mountain big sagebrush, antelope bitterbrush, and bluegrass with some scattered Jeffrey pine.
DISTRIBUTION AND EXTENT: Eastern California and western Nevada, on the east side of the Sierra Nevada Range. These soils are not extensive with about 5,000 acres of the series mapped to date. MLRA 22A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mono County (Toiyabe National Forest Area), California, 2006.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 10 inches (A1 and A2 horizons).
Paralithic contact - The boundary at 18 inches to underlying soft, weathered bedrock (Cr layer).
Particle-size control section - The zone from 10 to 18 inches (C1 and C2 horizons).