LOCATION OLOT OR+WA
Established Series
Rev. CTH/AON/RWL
02/2013
OLOT SERIES
The Olot series consists of moderately deep, well drained soils that formed in volcanic ash and colluvium and residuum weathered from basalt. Olot soils are on plateaus and mountains and have slopes of 2 to 90 percent. The mean annual precipitation is about 27 inches and the mean annual temperature is about 44 degrees F.
TAXONOMIC CLASS: Ashy over loamy-skeletal, glassy over isotic, frigid Typic Vitrixerands
TYPICAL PEDON: Olot stony ashy silt loam, wooded. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; duff, needles, twigs.
A1--1 to 3 inches; dark brown (10YR 3/3) stony ashy silt loam, pale brown (10YR 6/3) dry; weak medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine, medium and coarse roots; common very fine and few fine discontinuous pores; about 0.06 percent of the surface covered with stones; neutral (pH 6.6); abrupt smooth boundary. (2 to 4 inches thick)
A2--3 to 7 inches; dark yellowish brown (10YR 4/4) ashy silt loam, light yellowish brown (10YR 6/4) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine, medium, and coarse roots; common very fine continuous tubular pores; 5 percent cobbles; neutral (pH 6.6); clear smooth boundary. (0 to 6 inches thick)
Bw--7 to 20 inches; yellowish brown (10YR 5/4) ashy silt loam, very pale brown (10YR 7/4) dry; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine, medium, and coarse roots; many very fine and common fine, medium, and coarse continuous tubular pores; 5 percent cobbles; slightly acid (pH 6.4); abrupt wavy boundary. (8 to 14 inches thick)
2Bwb1--20 to 26 inches; strong brown (7.5YR 4/6) extremely cobbly silty clay loam, light yellowish brown (10YR 6/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, and medium and few coarse roots; common fine continuous tubular pores; 40 percent cobbles; 25 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (5 to 8 inches thick)
2Bwb2--26 to 31 inches; dark yellowish brown (10YR 4/4) extremely cobbly silty clay loam, light yellowish brown (10YR 6/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine, medium, and coarse roots; common fine continuous tubular pores; 60 percent cobbles, 15 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (4 to 13 inches thick)
2R--31 inches; fractured basalt.
TYPE LOCATION: Union County, Oregon; near road cut and north boundary of the Starkey Experimental Forest, in the NE1/4 NE1/4 section 19, T. 3S., R. 34E.
RANGE IN CHARACTERISTICS: These soils have moist bulk densities of 0.85 g/cc or less and contain 60 to 70 percent glass and less than 12 percent 15-bar moisture content (dry sample) in the ash overlay. Thickness of the ash ranges from 14 to 20 inches. Depth to bedrock ranges from 20 to 40 inches. The mean annual soil temperature ranges from 42 to 47 degrees F. These soils are usually moist but are dry between depths of 4 and 12 inches for 45 to 90 consecutive days following the summer solstice. The soils have 0 to 0.1 percent of the surface area covered with stones. The soil reaction is slightly acid or neutral.
The A horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 4 through 7 dry, and chroma of 2 through 4 moist and dry. It is ashy silt loam or stony ashy silt loam with 5 to 15 percent clay.
The Bw horizon has hue of 10YR or 7.5YR, value of 3 through 5 moist, 5 through 7 dry, and chroma of 3 through 5 moist and dry. It has 5 to 15 percent clay.
The buried 2Bb horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 3 through 7 dry, and chroma of 3 through 6 moist and dry. It is extremely cobbly or very cobbly silt loam, loam or silty clay loam and is 25 to 35 percent clay, 15 to 60 percent cobbles, 10 to 35 percent gravel, and 0 to 5 percent stones.
COMPETING SERIES: These are the
Brannan,
Capoose,
Crackler,
Elbowlake,
Kellerbutte,
Kootenai,
Natapoc,
Nevine,
Rouen,
Saska and
Vingulch soils. Brannan, Crackler,
Dufort, Elbowlake, Kellerbutte, Kootenai, Natapoc, Nevine, and Saska soils are greater than 40 inches to bedrock. Capoose soils have 1 to 12 percent clay in the lower particle-size control section and 30 to 60 percent volcanic glass in the upper particle-size control section. Rouen soils are 20 to 40 inches to argillite bedrock and the 2Bw horizon has less than 10 percent cobbles and more than 30 percent gravel. Vingulch soils have less than 18 percent clay in the lower part of the pscs with sandy loam, loamy sand, or loamy coarse sand fine-earth textures.
The
Crackercreek and
Dufort soils have a similar classification. Crackercreek soils are 40 to 60 inches to bedrock and have a glassy over mixed mineralogy. Dufort soils are very deep to bedrock and have a glassy over mixed mineralogy.
GEOGRAPHIC SETTING: Olot soils are on plateaus, canyons, mountains and structural benches. Elevations are typically 2,800 to 5,000 feet, commonly on north and northeast-facing slopes but range to 6,200 feet on south-facing slopes. Slopes range from 2 to 90 percent. These soils formed in silty volcanic ash deposited over a buried soil that formed in residuum and colluvium weathered from basalt. The climate is characterized by cold and wet winters and hot and dry summers. The average annual precipitation is 17 to 42 inches; the average annual temperature is 40 to 45 degrees F.; and the frost free period is 30 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Anatone,
Bocker,
Kamela,
Klicker,
Loneridge, and
Tolo soils. Anatone, Bocker, Kamela, Klicker, and Loneridge soils lack ashy surface layers with a low bulk density. Tolo soils are ashy over loamy and are more than 40 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability in the lower layers.
USE AND VEGETATION: Used mainly for timber production. Also used for wildlife habitat. Vegetation is western larch, Douglas fir, willow, mountain alder, common snowberry, elk sedge, and pinegrass.
DISTRIBUTION AND EXTENT: Northeastern Oregon and Southwestern Washington; MLRA 10. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Union County, Oregon, 1978.
REMARKS: Diagnostic features recognized in this pedon include:
Ochric epipedon
Cambic horizon - from 7 to 31 inches
A surface mantle that has a moist bulk density of less than 0.95 g/cubic centimeter and a ratio of measured clay to 15 bar water greater than 1.25.
Vitrixerands feature - andic soil properties from the mineral surface to 19 inches with more than 60 percent volcanic glass and glass aggregate and less than 12 percent 15-bar moisture content (dry).
Classification revised 08/01 from loamy-skeletal, mixed Mollic Eutroboralfs to ashy over loamy-skeletal, mixed, frigid Typic Vitrixerands based on addition of the Andisol order and the lack of an argillic horizon.
National Cooperative Soil Survey
U.S.A.