LOCATION WINDYGAP OREstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Xeric Haplohumults
TYPICAL PEDON: Windygap silt loam - clearcut, on a south-facing slope of 15 percent at an elevation of 850 feet. (Colors are for moist soil unless otherwise stated.)
A1--0 to 3 inches; dark brown (7.5YR 3/4) silt loam, brown (7.5YR 5/4) dry; moderate fine and medium granular structure; hard, firm, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine irregular and tubular pores; strongly acid (pH 5.4); clear smooth boundary.
A2--3 to 7 inches; dark brown (7.5YR 3/4) silt loam, brown (7.5YR 5/4) dry; moderate fine and medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine irregular and tubular pores; strongly acid (pH 5.2); clear smooth boundary. (Combined thickness of the A horizon is 2 to 23 inches)
Bt1--7 to 17 inches; dark red (2.5YR 3/6) silty clay, red (2.5YR 4/6) crushed and yellowish red (5YR 4/6) dry; moderate fine and medium subangular blocky structure; hard, firm, sticky and plastic; common fine and medium roots; many very fine and fine irregular and tubular pores; few faint dark red (2.5YR 3/6) clay films on faces of peds and lining pores; very strongly acid (pH 5.0); clear smooth boundary.
Bt2--17 to 43 inches; dark red (2.5YR 3/6) silty clay, red (2.5YR 4/6) crushed and yellowish red (5YR 4/6) dry; strong medium and coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; many distinct dark red (2.5YR 3/6) clay films on faces of peds and lining pores; 10 percent weathered siltstone gravel; very strongly acid (pH 4.8); clear smooth boundary.
Bt3--43 to 55 inches; dark red (2.5YR 3/6) silty clay, red (2.5YR 4/6) crushed and dry; moderate medium and coarse subangular blocky structure; very hard, very firm, sticky and plastic; few very fine roots; few very fine and fine tubular pores; many distinct dark red (2.5YR 3/6) clay films on faces of peds and lining pores; 10 percent weathered siltstone gravel; very strongly acid (pH 4.8); clear smooth boundary. (Combined thickness of the Bt horizon is 25 to 51 inches)
Crt--55 inches; highly weathered and fractured siltstone bedrock with many prominent dark red (2.5YR 3/6) clay films on rock fragments; few very fine roots penetrating fractures.
TYPE LOCATION: Douglas County, Oregon, about 8 miles north of Sutherlin; 1,215 feet west and 660 feet north of the southeast corner of section 12, T. 24 S., R. 6 W. (Latitude 43 degrees, 29 minutes, 37 seconds N; Longitude 123 degrees, 20 minutes, 57 seconds W)
RANGE IN CHARACTERISTICS: The soils are dry in all parts of the moisture control section for 45 to 80 consecutive days following the summer solstice. The mean annual soil temperature is 52 to 57 degrees F. Depth to bedrock is 40 to 60 inches. The particle-size control section has 35 to 55 percent clay and 0 to 14 percent rock fragments. It is very strongly acid to slightly acid throughout.
The A horizon has hue of 5YR or 7.5YR moist, and 7.5YR or 10YR dry, value of 3 to 5 moist, 4 to 7 dry and chroma of 2 to 6 moist and dry. It is silt loam or clay loam. Rock fragments are 0 to 14 percent gravel.
The Bt horizon has hue of 2.5YR to 7.5YR, value of 3 to 5 moist, 4 to 7 dry and chroma of 4 to 6 moist and 4 to 8 dry. It is silty clay loam, silty clay, or clay with 35 to 55 percent clay. Rock fragments are 0 to 10 percent gravel and 0 to 4 percent cobbles. Some pedons have up to 50 percent soft weathered fragments in the lower Bt horizon.
COMPETING SERIES: These are the Bellpine and Nekia series. Bellpine and Nekia soils are 20 to 40 inches deep to bedrock.
GEOGRAPHIC SETTING: Windygap soils are on hills and plateaus. The soils formed in residuum and colluvium from sandstone and siltstone from the Roseburg, Lookingglass, Flournoy, and Tyee Formations. Slopes are 2 to 60 percent. Elevations are 300 to 2,700 feet. The climate is characterized by warm, wet winters and hot, dry summers. The mean annual temperature is 50 to 55 degrees F. and the mean annual precipitation is 40 to 60 inches. The frost-free period is 120 to 235 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Atring, Bateman, Beekman, Bellpine, Chimneyrock, Dicecreek, Kanid, Oakland, Rosehaven, and Vermisa soils. Atring, Beekman, Kanid and Vermisa soils are loamy-skeletal and are on adjacent more steeply sloping positions. Bellpine and Oakland soils are 20 to 40 inches deep to bedrock and are on similar positions. Bateman and Rosehaven soils are greater than 60 inches deep to bedrock and are on similar positions. Chimneyrock soils are loamy-skeletal, formed over a conglomerate and are on similar positions.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Windygap soils are used for timber production, small grain, hay and pasture, watershed and wildlife habitat. Natural vegetation is Douglas fir, grand fir, Pacific madrone, ponderosa pine, western hazed, salal, cascade Oregongrape, tall Oregongrape, western swordfern and mountain brome.
DISTRIBUTION AND EXTENT: MLRA 2 and 5. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Douglas County, Oregon, 1992.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the surface to 7 inches (A1 and A2 horizons)
Argillic horizon - from 7 to 55 inches (Bt1, Bt2, and Bt3 horizons)
Particle-size control section - from 7 to 27 inches (Bt1 and upper 10 inches of the Bt2 horizon)
Base saturation is assumed to be less than 35 percent immediately above the paralithic contact.
Assumed to have 0.9 percent or more organic carbon in the upper 6 inches of the Bt1 horizon