LOCATION BROWNLEE ID+CA MT OR UTEstablished Series
The Brownlee series consists of deep and very deep, well drained soils with moderately slow permeability that formed in colluvium, residuum and old alluvium from coarse-grained intrusive rocks. Slopes range from 0 to 50 percent in foothills and valleys. The average annual precipitation is about 18 inches and the average annual temperature is about 47 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ultic Argixerolls
TYPICAL PEDON: Brownlee coarse sandy loam -- on a convex slope of 3 percent, in rangeland at 3,480 feet elevation. (Colors are for air-dry soil unless otherwise stated.)
A1--0 to 3 inches; dark grayish brown (10YR 4/2) coarse sandy loam, very dark brown (10YR 2/2) moist; moderate very thin platy structure parting to weak and moderate very fine and fine granular; hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine pores; 10 percent fine gravel; slightly acid (pH 6.2); clear wavy boundary.
A2--3 to 9 inches; dark grayish brown (10YR 4/2) coarse sandy loam, very dark brown (10YR 2/2) moist; weak very thin platy structure parting to weak and moderate very fine and fine granular; hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine pores; 10 percent fine gravel; slightly acid (pH 6.1); clear wavy boundary. (combined A horizon - 7 to 16 inches thick)
AB--9 to 12 inches; dark grayish brown (10YR 4/2) coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine pores; 10 percent fine gravel; moderately acid (pH 6.0); clear wavy boundary. (0 to 9 inches thick)
Bt1--12 to 20 inches; dark grayish brown (10YR 4/2) coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak coarse prismatic structure parting to weak medium subangular blocky; very hard, firm, slightly sticky and slightly plastic; common fine roots; common very fine pores; few faint clay films on faces of peds; common continuous, wavy lamellae 2 to 5 mm thick with continuous prominent clay films, very dark brown (7.5YR 2/2) to dark reddish brown (5YR 3/2); 10 percent fine gravel; moderately acid (pH 6.0); clear wavy boundary. (4 to 9 inches thick)
Bt2--20 to 28 inches; brown (7.5YR 4/3) coarse sandy clay loam, dark brown (7.5YR 3/2) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; very hard, firm, moderately sticky and moderately plastic; few fine roots; common fine pores; many distinct clay films on faces of peds; 10 percent fine gravel; common, continuous lamellae as described in Bt1; 10 percent fine gravel; moderately acid (pH 6.0); gradual smooth boundary. (5 to 21 inches thick)
Bt3--28 to 42 inches; brown (7.5YR 4/3) coarse sandy clay loam, dark brown (7.5YR 3/3) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; very hard, very firm, moderately sticky and moderately plastic; few fine roots; common fine and very fine pores; many distinct clay films on faces of peds; common discontinuous lamellae as described in Bt1; 10 percent fine gravel; moderately acid (pH 5.9); clear smooth boundary. (0 to 15 inches thick)
BC--42 to 45 inches; brown (10YR 4/3) fine gravelly coarse sandy loam, dark brown (10YR 3/3) moist; weak coarse prismatic structure; very hard, firm; few very fine roots; few fine pores; few discontinuous lamella as described in Bt1; 20 percent fine gravel; slightly acid (pH 6.2); gradual wavy boundary. (0 to 18 inches thick)
Cr--45 to 60 inches; hard grus grading to granodiorite.
TYPE LOCATION: Gem County, Idaho; about 5 miles northeast of Sweet; 2,100 feet north and 950 feet east of the southwest corner of section 12, T.8 N., R.1 E.; USGS Webb Creek Quadrangle; (Latitude - 44 degrees, 02 minutes, 38 seconds N. and Longitude - 16 degrees, 17 minutes, 24 seconds W.)
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 10 to 20 inches
(organic matter content is less than 1 percent below 20 inches)
Depth to base of argillic - 25 to 54 inches
Depth to paralithic contact - 40 inches or more
Reaction - moderately acid through neutral
Base saturation (10 to 30 inches - some part) - 50 to 75 percent
Moisture control section - dry for 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 47 to 53 degrees F.
A horizon
Hue - 7.5YR or 10YR
Value - 3 through 5 dry, 1 through 3 moist
Chroma - 1 through 3 dry or moist
Rock fragments 0 to 15 percent (mostly fine gravel)
Bt1 horizon
Hue - 7.5YR or 10YR
Value - 4 through 6 dry, 2 through 5 moist
Chroma - 2 through 4 dry and moist
Texture - COSL, L, SCL or CL
Clay content - 18 to 30 percent
Rock fragments - 0 to 15 percent (mostly fine gravel)
Lamellae - none through common
Bt2 and Bt3 horizons
Hue - 5YR through 2.5Y
Value - 4 through 6 dry, 3 through 5 moist
Chroma - 2 through 6 dry or moist
Texture - SCL, CL or L (more than 25 percent medium, coarse and very coarse sand)
Clay content - 20 to 35 percent
Rock fragments - 0 to 25 percent (mostly fine gravel)
Lamellae - few or common
Unweathered granitic rock commonly occurs above 60 inches (below the Cr horizon)
COMPETING SERIES: These are the Annum, Boyleston, Chirpchatter, Dryfalls (T), Ebadlow, Felton, Fisherhill, Goldendale, Hellake, Lompico, Lorena, Meland, Mendian (T), Meystre, Quiden, Rehfield, Robbscreek, Schumacher, Stacker, Stardust, Updegraff and Van Horn series. Annum soils are dry for 90 to 105 consecutive days, have a mantle of loess, have buried Bt horizons, and have 2Bk or 2BC horizons with a soil reaction of slightly to medium alkaline. Boyleston soils have Bt horizons that extend to depths of 60 inches or more and are dry 90 to 100 consecutive days. Chirpchatter soils are dry for more than 90 consecutive days, have O horizons, and Bt horizons that extend to depths of 60 inches or more. Dryfalls soils have NaF pH of 9.5 or greater in the 7 to 14 inch layer, 35 to 60 rock fragments in the lower part and are over basalt bedrock. Ebadlow soils have silty textures in the upper Bt horizon, are 25 to 36 inches to skeletal material, and dry 90 to 105 consecutive days. Felton soils have more than 50 percent shale fragments in the C horizons and dry for more than 90 consecutive days. Fisherhill soils have Bt horizons that extend to depths of 60 inches or more and are dry 90 to 105 consecutive days. Goldendale soils have Bt horizons that extend to depths of 60 inches or more and less than 25 percent medium sand or coarser in the particle-size control section Hellake soils lack Cr horizons, lamellae in the Bt horizon and under native conditions have O horizons. Lompico, Lorena and Meland soils are 20 to 40 inches deep. Mendian soils have very gravelly 3Btb horizons at depths of 25 to 40 inches and are dry 90 to 100 consecutive days. Meystre soils have an O horizon and have less than 25 percent medium sand or coarser in the particle-size control section. Quiden soils have an O horizon, Bt horizons that extend to depths of 60 inches or more and less than 25 percent medium sand or coarser in the particle-size control section. Rehfield soils have an aridic moisture regime. Robbscreek soils are 20 to 40 inches deep to a lithic contact. Schumacher soils are 40 to 60 inches to a lithic contact (metasediments), have less than 25 percent medium or coarser sand in the particle-size control section and dry 45 to 60 consecutive days. Stacker soils are 20 to 40 inches deep over basalt and dry for 90 to 105 consecutive days. Stardust soils are greater than 60 inches to bedrock, lack lamellae in the Bt horizons, and have an O horizon. Updegraff soils are dry more than 90 consecutive days and have an O horizon. Van Horn soils lack Cr horizons, lamellae in the Bt horizon and under native conditions have O horizons.
GEOGRAPHIC SETTING: Brownlee soils are nearly level to steep on hill summits, backslopes and footslopes, and fan remnants at elevations of 2,500 to 5,800 feet. Slopes range from 0 to 50 percent. These soils formed in colluvium and residuum from granitic rocks on hills and in old alluvium from coarse-grained acid and intermediate intrusive rocks on fan remnants. Average annual precipitation is 13 to 23 inches. Average annual temperature is 45 to 51 degrees F. Frost-free period is 90 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ola and Rainey series. Ola and Rainey soils lack argillic horizons. Ola soils have a mean annual soil temperature of less than 47 degrees F. Rainey soils are 20 to 40 inches deep. Ola soils are on steep north-facing slopes. Rainey soils are on south-facing slopes.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Brownlee soils are used mainly for rangeland and wildlife habitat. Native vegetation is bluebunch wheatgrass, Idaho fescue, xeric big sagebrush and antelope bitterbrush. Some areas are used for irrigated or nonirrigated cropland (small grains) and hayland/pasture.
DISTRIBUTION AND EXTENT: West-central Idaho, western Montana, northern Utah and eastern Oregon. MLRA 10. Brownlee soils are of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Squaw Creek Project, Gem and Boise Counties, Idaho, 1939.
REMARKS: The original concept of this series was a deep soil (40 to 60 inches) over residual granitic grus on hills. The subsequent expansion to include very deep phases on fan remnants would not be allowed under current series criteria. These areas will need to be further investigated during an MLRA update project.
Diagnostic horizons and other features recognized in this pedon:
Mollic epipedon - zone 0 to 12 inches (A1, A2 and AB horizons)
Argillic horizon - zone 20 to 42 inches (Bt2 and Bt3 horizons)
Paralithic contact - at 45 inches (Cr horizon)
Particle-size control section - zone 20 to 40 inches
Soil moisture regime - xeric
Mica is a significant and obvious mineral in all pedons.
ADDITIONAL DATA: Characterization sample no. 56 Ida 2312 (University of Idaho & SCS Riverside Lab, Bulletin 360, May 1961)