LOCATION HIETANEN CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Haploxerults
TYPICAL PEDON: Hietanen gravelly loam, on a southwest facing 20 percent slope under a cover of ponderosa pine and white fir at an elevation of 3600 feet, (1097 m). When described on 7/13/99 the soil was dry throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 1 inches, (0 to 3 cm); slightly decomposed plant material; abrupt smooth boundary.
A--1 to 3 inches, (3 to 8 cm); light brown (7.5YR 6/4) gravelly loam, brown (7.5YR 4/3) moist; 20 percent clay; moderate fine and medium granular structure; soft, very friable, slightly sticky, slightly plastic; common very fine, fine and medium roots; many very fine, fine and medium irregular and tubular pores; 25 percent gravel; moderately acid, pH 6.0 by Hellige-Truog; NaF pH 9.8; clear smooth boundary. (2 to 4 inches, (5 to 10 cm) thick)
Bt1--3 to 8 inches, (8 to 20 cm); light brown (7.5YR 6/4) gravelly loam, brown (7.5YR 4/4) moist; 24 percent clay; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine, fine and medium roots; many very fine and fine tubular pores; 50 percent faint clay films; 5 percent cobbles and 15 percent gravel; slightly acid, pH 6.2 by Hellige-Truog; NaF pH 10.0; gradual smooth boundary.
Bt2--8 to 19 inches, (20 to 48 cm); reddish yellow (7.5YR 6/6) silt loam, reddish brown (5YR 4/4) moist; 27 percent clay; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine, fine and medium roots; common very fine and fine and few medium tubular pores; 50 percent faint clay films; 10 percent gravel; moderately acid, pH 5.8 by Hellige-Truog; NaF pH 9.5; gradual smooth boundary.
Bt3--19 to 30 inches, (48 to 76 cm); yellow (10YR 8/6) silt loam, brownish yellow (10YR 6/6) moist; 24 percent clay; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine, fine, medium and coarse roots; common very fine and fine tubular pores; 50 percent distinct clay films; 12 percent gravel; strongly acid, pH 5.5 by Hellige-Truog; NaF pH 9.2; gradual smooth boundary.
Bt4--30 to 53 inches, (76 to 135 cm); yellow (10YR 7/6) silt loam, yellowish brown (10YR 5/6) moist; 22 percent clay; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; 50 percent distinct clay films; 10 percent gravel; strongly acid, pH 5.5 by Hellige-Truog; NaF pH 9.5; clear smooth boundary. (Combined thickness of the Bt horizon is 37 to 57 inches, (94 to 145 cm) thick)
Cr--53 inches, (135 cm); very weakly cemented phyllite bedrock; few very fine, fine and medium roots; few very fine irregular and tubular pores; strongly acid, pH 5.5 by Hellige-Truog.
TYPE LOCATION: Butte County, California, about 3.2 miles northeast of Sawmill Peak, approximately 1500 feet north and 360 feet west of the southeast corner of Section 22, Township 23 N., Range 4 E., 39 degrees, 49 minutes, 60 seconds North latitude and 121 degrees, 30 minutes, 20 seconds West longitude, NAD83 - U.S.G.S Quad: Paradise East, California.
RANGE IN CHARACTERISTICS: Depth to paralithic bedrock is 40 to 60 inches, (102 to 152 cm). The mean annual soil temperature is 50 to 57 degrees F, (10 to 14 degrees C). The particle-size control section averages 24 to 35 percent clay and 2 to 35 percent rock fragments, mostly gravel. Mineralogy is mixed. Rock fragments on the surface range from 5 to 30 percent gravel, 0 to 10 percent cobbles and 0 to 5 percent stones. Some pedons have very gravelly Bt/Cr horizons.
The A horizon dry color is 10YR 5/2, 5/3, 6/4, 7.5YR 5/4, 6/3, 6/4, 7/3, 7/4, or 5YR 6/4. Moist color is 10YR 3/2, 4/2, 4/3, 7.5YR 3/4, 4/2, 4/3, 4/4, 5YR 4/3 or 4/4. Texture is loam, gravelly loam, very gravelly loam or silt loam. Clay content ranges from 18 to 27 percent. Rock fragments range from 5 to 40 percent gravel. Reaction ranges from moderately acid to neutral.
The Bt horizon dry color is 7.5YR 5/4, 5/6, 6/4, 6/6, 5YR 6/4, 6/6, 10YR 5/4, 6/4, 7/2, 7/4, 7/6, 8/6, 2.5Y 5/3 or 7/4. Moist color is 7.5YR 4/3, 4/4, 4/6, 5/6, 5YR 4/4, 4/6, 5/6, 10YR 4/2, 4/3, 5/4, 5/6, 6/6, 2.5Y 4/2, 4/3 or 5/4. Hues of 10YR and 2.5Y normally occur in the lower part of the horizon. Texture is loam, gravelly loam, clay loam, gravelly clay loam, silt loam, gravelly silt loam, silty clay loam or gravelly silty clay loam. Clay content ranges from 22 to 35 percent. Rock fragments range from 2 to 30 percent gravel and 0 to 10 percent cobbles. Reaction ranges from strongly acid to slightly acid.
COMPETING SERIES: These are the Jocal and Mac series. Jocal soils are very deep. Mac soils are moderately deep.
GEOGRAPHIC SETTING: Hietanen soils are on ridge tops and side slopes on metamorphic Sierra Nevada mountains. Slopes range from 3 to 70 percent. These soils formed in residuum and colluvium weathered from metasedimentary rocks. Elevation is 2000 to 4000 feet, (610 to 1219 m). Mean annual precipitation is 65 to 72 inches, (1651 to 1829 mm). The mean annual temperature is 53 to 55 degrees F, (12 to 13 degrees C). Frost free season is 160 to 185 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Toadtown, Mac and Spine soils. Toadtown soils are fine and very deep. Mac soils are moderately deep. Spine soils are loamy-skeletal and shallow.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; moderate saturated hydraulic conductivity in the A horizon and moderate to moderately slow in the Bt horizon.
USE AND VEGETATION: This soil is used for timber production, wildlife habitat and watershed. Vegetation is ponderosa pine, white fir, tanoak, Douglas-fir, California black oak, incense cedar, sugar pine, dogwood, deerbrush, bigleaf maple, whiteleaf manzanita, brackenfern, prostrate ceanothus, Sierra gooseberry, Orcutt brome, iris, whitevein shinleaf and broadleaf starflower.
DISTRIBUTION AND EXTENT: Butte County, California and occurs in the M261EF (Metamorphic Foothills) subsection of the M261E (Sierra Nevada) section. MLRA 22A - Sierra Nevada Range. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name is from Anna Hietanen, a geologist who mapped much of the Sierra Nevada in Butte County.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section - zone from 3 to 23 inches, (8 to 58 cm)
Ochric epipedon - zone from 1 to 3 inches, (3 to 8 cm) (A)
Argillic horizon - zone from 3 to 30 inches, (8 to 76 cm) (Bt1, Bt2, Bt3)
Paralithic contact - 53 inches, (135 cm)
The soil moisture control section - zone from 8 to 19 inches, (20 to 48 cm) is dry in all parts from about mid June to mid October (about 120 days).