LOCATION PEAVINE OREstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Typic Haplohumults
TYPICAL PEDON: Peavine silty clay loam, native pasture. (Colors are for moist soil unless otherwise noted.)
A--0 to 4 inches; very dark brown (7.5YR 2/2) and dark brown (7.5YR 3/2) silty clay loam, brown (7.5YR 4/2 and 4/3) dry; moderate fine subangular blocky structure; friable, moderately sticky and moderately plastic; many very fine and fine roots; common very fine tubular pores; few fine shale fragments; moderately acid (pH 5.6); clear smooth boundary. (3 to 7 inches thick)
AB--4 to 10 inches; dark brown (7.5YR 3/2) silty clay loam, brown (7.5YR 4/4) dry; moderate fine subangular blocky structure; firm, moderately sticky and moderately plastic; many very fine and fine roots; many very fine tubular pores; few fine shale fragments; strongly acid (pH 5.5); clear wavy boundary. (0 to 8 inches thick)
BAt--10 to 15 inches; dark reddish brown (5YR 3/4) silty clay, yellowish red (5YR 4/6) dry; moderate fine subangular blocky structure; firm, very sticky and very plastic; many very fine through medium roots; few fine tubular pores; few faint clay films on surfaces of peds and in pores; very strongly acid (pH 4.8); clear wavy boundary. (0 to 8 inches thick)
Bt--15 to 26 inches; yellowish red (5YR 4/6) silty clay, yellowish red (5YR 5/6) dry; moderate medium subangular blocky structure; firm, very sticky and very plastic; many very fine through medium roots; many very fine tubular pores; common faint clay films on surfaces of peds and in pores; many very fine shale parafragments; very strongly acid (pH 4.6); clear wavy boundary. (8 to 20 inches thick)
BCt--26 to 36 inches; yellowish red (5YR 4/6) silty clay, yellowish red (5YR 5/6) dry; moderate fine subangular blocky structure; firm, very sticky and very plastic; common very fine roots; many very fine pores; faint nearly continuous clay films on faces of peds and in pores; many very fine and fine variegated brown and yellow shale parafragments; very strongly acid (pH 4.6); gradual wavy boundary. (5 to 16 inches thick)
Crt1--36 to 49 inches; light yellowish brown (10YR 6/4) and brownish yellow (10YR 6/6) fractured partially consolidated shale bedrock; fractures filled with yellowish red (5YR 4/6) silty clay loam, yellowish red (5YR 5/6) dry; massive; firm, sticky and plastic; few very fine roots in fractures only; many distinct yellowish red (5YR 4/6) clay films on shale fragments; very strongly acid (pH 4.6); gradual wavy boundary. (0 to 20 inches thick)
Crt2--49 to 64 inches; light yellowish brown (10YR 6/4) and brownish yellow (10YR 6/6) fractured partially consolidated bedrock; fractures filled with light yellowish brown (10YR 6/4) to brownish yellow (10YR 6/6) silty clay loam, yellow (10YR 7/6) dry; massive; few very fine roots in fractures only; many distinct yellowish red (5YR 4/6) clay films on shale fragments; very strongly acid (pH 4.6); gradual wavy boundary. (0 to 20 inches thick)
R--64 inches; light yellowish brown (10YR 6/4) and brownish yellow (10YR 6/6) fractured very hard bedrock.
TYPE LOCATION: Yamhill County, Oregon; about 50 yards north on field road from county road along ridgetop in the southeastern corner of Moore's Valley; SW1/4 SW1/4 SE1/4 of section 10, T. 3 S., R 5 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is typically 47 to 55 degrees F., and may range to 57 degrees F. in the more southern reaches of the Cascade and Coast Ranges in Oregon. The soil is usually moist and is dry between depths of 4 and 12 inches for less than 45 consecutive days in the four-month period following the summer solstice in most years. The particle-size control section is 40 to 60 percent clay with 0 to 5 percent total rock fragments and 0 to 50 percent pararock fragments. The solum is 20 to 40 inches thick over firm, fractured, partially consolidated sandstone, siltstone, basalt, tuffaceous rock, or shale that commonly is consolidated below 60 inches.
The A horizon has hue of 10YR to 5YR, value of 2 or 3 moist, 4 or 5 dry and chroma of 2 to 4 moist and dry. Texture of the fine-earth fraction is silty clay loam with 27 to 40 percent clay. It has 0 to 5 percent gravel and 0 to 20 percent paragravel. Reaction is moderately acid to very strongly acid. . The surface layer may have weakly smeary or moderately smeary consistence when the soil is derived from igneous parent materials.
An ABt or Bat horizon is present in some pedons.
The Bt horizon has hue of 5YR or 2.5YR, value of 3 or 4 moist, 4 to 6 dry and chroma of 4 to 8 moist and dry. Texture of the fine-earth fraction is silty clay, or clay with 40 to 60 percent clay. It has 0 to 5 percent gravel, 0 to 50 percent paragravel and 0 to 10 percent paracobbles. Reaction is strongly acid or very strongly acid.
The BCt horizon has hue of 5YR or 2.5YR, value of 4 or 5 moist, 5 to 7 dry and chroma of 4 to 6 moist and dry. Texture of the fine-earth fraction is silty clay, or clay with 40 to 60 percent clay. It has 0 to 10 percent gravel, 0 to 50 percent paragravel and 0 to 10 percent paracobbles. Reaction is strongly acid or very strongly acid.
The Crt horizon consists of partially weathered, fractured sandstone, siltstone, basalt, tuffaceous rock, or shale with the fractures filled with the fine-earth materials from the horizon above. Volume of interstitial material ranges from near 0 to 25 percent.
COMPETING SERIES: These are the Absaquil, Hazelcamp, and Skookumhouse soils, and the Apt, McDuff, and Wintley series in a similar family. Absaquil and Skookumhouse soils are 40 to 60 inches deep to a paralithic bedrock contact. In addition, Absaquil soils have hue yellower than 5YR in the particle-size control section. Hazelcamp soils are 20 to 40 inches deep to a paralithic contact and lack rock fragments throughout the solum. In addition, Hazelcamp and Skookumhouse soils have 35 to 45 percent clay in the particle-size control section. Apt, McDuff, and Wintley soils have an isotic mineralogy family class. In addition, Apt and Wintley soils are deeper than 60 inches to bedrock. Wintley soils have a very gravelly 2C horizon at a depth of 40 inches or more and dominated by rounded rock fragments.of alluvial origin. McDuff soils are 20 to 40 inches deep to a paralithic contact and have hue yellower than 5YR in the argillic horizon.
GEOGRAPHIC SETTING: Peavine soils occur on summits, shoulder slopes and backslopes of mountains. Elevations are 200 to 2,800 feet. Where these soils are mapped in the Oregon Coast Range elevations are typically 200 to 1,800 feet and reach heights of 2,600 feet in the more southern portions of the range in SW Oregon. Where these soils are mapped in the Oregon Cascade Range the typical elevations are 700 to 2,400 feet, and range up to 2,800 feet in the most southern geographic extent of the Cascades. Slopes are 2 to 75 percent. The soils formed in clayey colluvium and residuum derived primarily from sandstone, siltstone, or shale but also includes weathered basalt or tuffaceous rock. The climate is characterized by warm wet winters and hot moist summers. The mean annual precipitation is 55 to 90 inches. The mean January temperature is 37 degrees F. and the mean July temperature is 65 degrees F. The mean annual temperature is 45 to 55 degrees F. The frost-free season is 145 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Apt, Bohannon, Digger, Ead, Honeygrove, McDuff, Melby, Olyic, Preacher, Remote, Shivigny, and Umpcoos. All of these soils occur on mountains. Bohannon, Digger, Preacher, Remote, and Umpcoos soils have less than 35 percent clay in the particle-size control section and have a solum less than 40 inches thick. Ead and Melby soils lack an argillic horizon. Apt and McDuff soils have hues of 10YR or 7.5YR in the particle-size control section. Honeygrove soils are greater than 60 inches deep to bedrock. Olyic soils have less than 35 percent clay in the argillic horizon. Shivigny soils are clayey-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: The soils are used mainly for timber production, recreation, wildlife habitat and watersheds with minor acreage used for hay, pasture, and Christmas trees. Native vegetation is Douglas fir, bigleaf maple, red alder, western hazel, vine maple, salal, Pacific dogwood, cascade Oregongrape, creambush oceanspray, western brackenfern, western swordfern, and baldhip rose. Minor amounts of western hemlock and western redcedar may also be present in some areas.
DISTRIBUTION AND EXTENT: Coast Range and western slopes of the Cascade Range, Oregon; MLRA 1, 3. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Benton County Area, Oregon, 1970.
REMARKS: Diagnostic horizons and features of this pedon include:
Umbric epipedon - from surface to 10 inches (A and AB horizons).
Argillic horizon - from 10 to 36 inches (Bat, Bt and BCt horizons).
Paralithic contact - 36 inches (Crt1 horizon).
Lithic contact - 64 inches (R).
Depth to diagnostic horizons and features are measured from the top of the first mineral layer.
Note: 10/03 - The series type location for the Peavine soil needs to be relocated into the udic moisture regime during the Yamhill County soil survey update to better reflect the modal series concept and classification, along with use and management interpretations.
ADDITIONAL DATA: Physical and chemical data available for typifying pedon (S62 Oreg. 36-5) SCS Riverside Soil Survey Lab.