LOCATION BENZARINO               WA

Established Series
Rev. TMR/CAB/SBC
01/2023

BENZARINO SERIES

The Benzarino series consists of shallow, well drained soils formed in volcanic ash mixed with glacial drift and colluvium over gneiss, granite, or granodiorite bedrock. Benzarino soils are found on slopes of 0 to 15 percent on bedrock benches and valley walls of glaciated mountain landscapes. The mean annual precipitation is about 1,900 millimeters and the mean annual air temperature is about 7 degrees C.

TAXONOMIC CLASS: Ashy, amorphic, frigid Lithic Udivitrands

TYPICAL PEDON: Benzarino cobbly ashy sandy loam, located on a south facing forested bedrock bench position with a slope of 5 percent and an elevation of 350 meters. About 20 percent of the soil surface is covered by subangular cobbles and stones. When described on June 11, 2008 the soil was moist throughout. (Colors are for moist soil unless otherwise noted)

Oi--0 to 4 cm; slightly decomposed needles, leaves, and twigs; abrupt smooth boundary.

Oa--4 to 6 cm; dark brown (7.5YR 3/2) highly decomposed plant material, brown (7.5YR 5/2) dry; very strongly acid (pH 5.0); abrupt wavy boundary.

Bw1--6 to 14 cm; brown (7.5YR 4/4) cobbly ashy sandy loam, brown (7.5YR 5/4) dry; moderate medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; few very fine, many fine to medium, and common coarse roots; many fine to medium irregular pores; 5 percent fine gravel, 5 percent medium and coarse gravel, 10 percent cobbles, and 5 percent stones; very strongly acid (pH 5.0); clear wavy boundary.

Bw2--14 to 31 cm; yellowish red (5YR 4/6) cobbly ashy sandy loam, yellowish red (5YR 5/6) dry; moderate medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; few very fine and common fine to medium roots; many fine to medium irregular pores; 5 percent fine gravel, 5 percent medium and coarse gravel, 10 percent cobbles, and 5 percent stones; strongly acid (pH 5.5); abrupt wavy boundary.

Bw3--31 to 45 cm; dark brown (7.5YR 3/3) cobbly ashy sandy loam, brown (7.5YR 5/3) dry; moderate medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine to fine and few medium roots; common fine to medium irregular pores; 5 percent fine gravel, 5 percent medium and coarse gravel, 10 percent cobbles, and 5 percent stones; strongly acid (pH 5.5); very abrupt wavy boundary.

R--45 cm; gneiss bedrock.

TYPE LOCATION: Whatcom County, Washington; approximately 500 meters southwest of the town of Diablo; 380 meters east and 160 meters south of the northwest corner of section 8, T. 37 N., R. 13 E. Willamette Meridian; Diablo Dam, Washington USGS quadrangle; 48 degrees, 42 minutes, 42 seconds north latitude and 121 degrees, 8 minutes, 43 seconds west longitude; UTM 636422 meters E, 5397069 meters N, zone 10N NAD83.

RANGE IN CHARACTERISTICS: Depths to diagnostic horizons and features start from the mineral soil surface.

Mean annual soil temperature - 5 to 8 degrees C. Frigid soil temperature regime.
Moisture control section - dry 30 to 45 consecutive days. Udic soil moisture regime.
Depth to lithic contact - 25 to 50 cm
Reaction - very strongly acid to strongly acid
Particle size control section:
Clay content - 2 to 10 percent through the profile
Rock fragments - 0 to 35 percent fine to coarse gravel, 0 to 15 percent cobbles, 0 to 5 percent stones, 0 to 35 percent total through the profile

Bw1 horizon
Hue - 7.5YR or 10YR
Value - 3 to 4 moist, 4 to 6 dry
Chroma - 3 to 6 moist or dry
Fine earth texture - ashy SL, ashy FSL
Thickness - 5 to 10 centimeters

Bw2 and Bw3 horizons
Hue - 5YR, 7.5YR, or 10YR
Value - 3 to 4 moist, 4 to 6 dry
Chroma - 3 to 6 moist or dry
Fine earth texture - ashy SL, ashy FSL
Combined thickness - 15 to 40 centimeters

COMPETING SERIES: This is the Flyvalley series. Flyvalley soils are ashy silt loam, ashy loam, or ashy very fine sandy loam in the particle-size control section.

GEOGRAPHIC SETTING: Benzarino soils are found on slopes of 0 to 15 percent on bedrock benches and valley walls of glaciated mountain landscapes at elevations from 150 to 1000 meters. They formed in volcanic ash mixed with glacial drift and colluvium over gneiss, granite, or granodiorite bedrock. The climate is characterized by cool, dry summers and cold, wet winters. Mean annual precipitation ranges from 1300 to 2500 millimeters. Mean annual air temperature ranges from 4 to 9 degrees C. Frost-free season is 60 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cosho, Ragged, and Tricouni soils. Cosho soils are moderately deep to a lithic contact. Ragged and Tricouni soils are very deep.

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

USE AND VEGETATION: Benzarino soils support wildlife habitat, recreation, and watershed drainage. Native vegetation consists of western hemlock, Douglas-fir, western redcedar, pachistima, Cascade Oregon grape, twinflower, western prince's-pine, kinnikinnick, rattlesnake plantain, and salal.

DISTRIBUTION AND EXTENT: North Cascade Mountains, Washington. MLRA 3. Series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon.

SERIES ESTABLISHED: North Cascades National Park Service Complex, Whatcom County, Washington, 2011.

REMARKS: Diagnostic horizons and features recognized in this pedon include:
Particle-size control section - 6 to 45 cm
Ochric epipedon - 0 to 18 cm (Oi, Oa, Bw1 and upper 4 cm of Bw2 horizon)
Andic soil properties - 6 to 45 cm (Bw1, Bw2, and Bw3 horizons)
Cambic horizon - 6 to 45 cm (Bw1, Bw2, and Bw3 horizons)
Lithic contact - 45 cm

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National Cooperative Soil Survey
U.S.A.