LOCATION BROCK NV+OR
Established Series
Rev. ELS/RLB/TM/JBF
02/2016
BROCK SERIES
The Brock series consists of shallow, well drained soils that formed in alluvium derived from mixed rocks. Brock soils are on dissected terrace side slopes and have 4 to 50 percent slopes. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Xeric Argidurids
TYPICAL PEDON: Brock very cobbly loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 cm; light brownish gray (10YR 6/2) very cobbly loam, dark grayish brown (10YR 4/2) moist; moderate thin and medium platy structure; soft, very friable, slightly sticky, slightly plastic; common very fine roots; many very fine and fine vesicular, and common fine tubular pores; 20 percent gravel and l5 percent cobbles; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (0 to 8 cm thick)
A2--5 to 13 cm; light gray (10YR 7/2) very gravelly loam, dark grayish brown (10YR 4/2) moist; moderate thin and medium platy structure; slightly hard, very friable, slightly sticky, slightly plastic; many very fine roots; common very fine and fine vesicular and tubular pores; 30 percent gravel and 10 percent cobbles; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (5 to 10 cm thick)
Bt--13 to 23 cm; light gray (10YR 7/2) very gravelly sandy clay loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; hard, very friable, sticky, plastic; common very fine roots; common very fine and fine tubular pores; common thin clay films in pores, and many thin clay films on faces of peds; 30 percent gravel and l5 percent cobbles; slightly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (8 to 15 cm thick)
Bk-- 23 to 36 cm; light gray (10YR 7/2) extremely cobbly sandy loam, brown (10YR 5/3) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky, plastic; few very fine, fine and medium horizontal roots; common very fine and fine tubular pores; few thin clay films in pores; 35 percent gravel and 25 percent cobbles; slightly effervescent but strongly effervescent in soft filaments; strongly alkaline (pH 8.8); very abrupt boundary. (8 to 15 cm thick)
Bqkm--36 to 48 cm; light gray (10YR 7/2) and very pale brown (10YR 7/3) indurated duripan, pale brown (10YR 6/3) and light yellowish brown (10YR 6/4), moist; massive; very hard and extremely hard, very firm and extremely firm, violently effervescent.
TYPE LOCATION: Eureka County, Nevada; about 4.5 miles northeast of Beowawe, Nevada; 2,400 feet north and 2,000 feet west of the apparent southeast corner of sec. l5, T. 32N., R.49E.; USGS Bobs Flat 7.5 minute topographic quadrangle; latitude 40 degrees 38 minutes 45 seconds N and longitude 116 degrees 25 minutes 55 seconds W; WGS84 Decimal Degrees 40.6458333 latitude, -116.4319444 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the winter and dry from late spring through mid-autumn. Aridic bordering on xeric.
Mean annual soil temperature: 8 to 9 degrees C.
Depth to duripan: 20 to 50 cm.
Particle-size control section - Clay content: 18 to 30 percent.
Rock fragments: 50 to 75 percent rock fragments consisting of 20 to 45 percent gravel and 10 to 30 percent cobbles.
A horizon
Value: 6 or 7 dry, 3 or 4 moist.
Chroma of 2 or 3.
Bt horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 through 4.
Texture: Sandy clay loam, clay loam, loam or very fine sandy loam.
Structure: Weak or moderate, fine or medium subangular blocky structure.
Other features: Thin Bk horizons above the duripan are in some pedons.
COMPETING SERIES: These are the
Cleet,
Deepeek,
Hotcreek,
Indicove,
Lapon, Littlealie,
Malmesa,
Oleman,
Shinnpeak,
Troughs,
Vinini and
Wanapum series.
Cleet and
Deepeek soils have noncalcareous A and Bt horizons.
Hotcreek soils have soil temperature of 9 to 11 degrees C., and have bedrock immediately below the duripan and within 20 to 36 cm.
Indicove and Littlealie soils are moist for 10 to 20 days during July to October due to convection storms.
Lapon,
Troughs and
Vinini soils have bedrock within 100 cm.
Malmesa soils have soil temperature of 12 to 15 degrees C. and have bedrock at 36 to 50 cm.
Oleman soils have soil temperature of 13 to 14 degrees C. and are moist for 10 to 20 days during July to October due to convection storms.
Shinnpeak and
Wanapum soils are noncalcareous above the duripan.
GEOGRAPHIC SETTING: Brock soils are on dissected terraces and alluvial fans at elevations of 1,220 to 1,710 meters. Slopes are 4 to 50 percent. The soils formed in alluvium derived from mixed rocks. The average annual temperature is 7 to 8 degrees C; average annual precipitation is 200 to 250 mm, ranging as low as 150 mm in central Oregon; and the frost-free season is about 100 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Alley,
Boulflat,
Chiara,
Rad and
Tenabo soils. Alley soils have fine-loamy control sections and lack duripans capping bedrock below 50 cm. Chiara soils lack argillic horizons and have loamy control sections. Rad soils lack argillic horizons and duripans and have coarse-silty control sections. Tenabo soils have loamy natric horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Rangeland and wildlife habitat. The vegetation is principally big sagebrush, littleleaf horsebrush, spiny hopsage, Sandberg bluegrass and cheatgrass.
DISTRIBUTION AND EXTENT: North-central Nevada. Brock soils are moderately extensive. MLRA 24 and 25.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Eureka County (Tuscarora Mountain Area), Nevada, 1968.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 13 cm (A1 and A2 horizons.
Argillic horizon - The zone from 13 to 23 cm (Bt horizon)
Cemented duripan - the zone from 36 to 48 cm (Bqkm horizon)
Particle size control section - the zone from 13 to 36 cm (Bt and Bk horizons)
National Cooperative Soil Survey
U.S.A.