LOCATION LOOKINGGLASS OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Xerertic Argialbolls
TYPICAL PEDON: Lookingglass silt loam, cultivated, on a 2 percent slope at an elevation of 2950 feet. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 6 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine to medium irregular and tubular pores; neutral (pH 6.8); abrupt smooth boundary.
A--6 to 11 inches; dark brown (10YR 3/3) silt loam, brown (10YR 4/3) dry; weak medium and coarse prismatic structure parting to weak fine subangular blocky; hard, friable, moderately sticky and moderately plastic; many very fine roots; common very fine tubular pores; neutral (pH 6.6); clear smooth boundary. (Combined thickness of the A horizon is 10 to 24 inches)
E1--11 to 16 inches; dark grayish brown (10YR 4/2) silt loam, grayish brown (10YR 5/2) dry; weak medium prismatic structure parting to weak fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular pores; few distinct dark gray siliceous coatings on peds; neutral (pH 6.6); clear smooth boundary.
E2--16 to 21 inches; dark gray (10YR 4/1) silt loam, gray (10YR 6/1) dry; massive; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; few very fine to medium tubular pores; few 1 to 3 mm black redox concretions; neutral (pH 6.6); abrupt smooth boundary. (Combined thickness of the E horizon is 1/2 to 22 inches)
2Bt1--21 to 28 inches; dark brown (10YR 3/3) clay, brown (10YR 4/3) dry; very dark gray organic coatings on surfaces of peds; moderate coarse prismatic structure parting to strong medium blocky; extremely hard, very firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; many 1 to 3 mm black redox concretions and stains; continuous distinct clay films on faces of peds and in pores; neutral (pH 6.6); clear wavy boundary.
2Bt2--28 to 38 inches; dark brown (10YR 3/3) clay, brown (10YR 4/3) dry; dark gray stains on surfaces of peds; strong coarse prismatic structure; extremely hard, very firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; many black redox concretions and stains; continuous distinct clay films on faces of peds and in pores; neutral (pH 6.6); gradual wavy boundary. (Combined thickness of the 2Bt horizon is 6 to 32 inches)
2C--38 to 60 inches; brown (10YR 4/3) silty clay loam, pale brown (10YR 6/3) dry; massive; hard, firm, sticky and plastic; many black redox concretions and stains; neutral (pH 6.6).
TYPE LOCATION: Union County, Oregon; 1,280 feet east and 600 feet south of the northwest section corner in NE1/2 NW1/4 section 25, T. 1 N., R. 38 E. (Latitude 45 degrees, 32 minutes, 32 seconds N, Longitude 118 degrees, 00 minutes, 33 seconds W)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 50 degrees F. The soils are usually moist but are dry in all parts between depths of 4 and 12 inches for 60 to 80 consecutive days following the summer solstice. Depth to bedrock is 60 inches or more. The mollic epipedon is 10 to 24 inches thick. Depth to the clayey argillic horizon is 12 to 30 inches. The soil reaction is slightly acid or neutral.
The Ap and A horizons have value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It has 0 to 10 percent gravel, 0 to 15 percent cobbles, and 0 to 20 percent stones.
The E horizon has value of 4 or 5 moist, 5 to 7 dry and chroma of 1 or 2 moist and dry. A stone line is at the lower boundary in some pedons. It is silt loam or silty clay loam with 0 to 10 percent gravel and 0 to 5 percent cobbles. Few to common black redoximorphic concretions occur in some pedons.
The 2Bt horizon has value of 3 or 4 moist, 4 to 6 dry and chroma of 3 or 4 moist and dry. It is silty clay loam, silty clay or clay and averages 35 to 50 percent clay. It has 0 to 10 percent gravel and 0 to 15 percent cobbles.
The 2C horizon, when present, is similar in color to the 2Bt horizon. It is silty clay loam or cobbly silty clay loam with 27 to 35 percent clay. It has 0 to 25 percent cobbles and 0 to 15 percent gravel.
COMPETING SERIES: This is the Conley series. Conley soils are somewhat poorly drained and have chroma of 2 or less in the argillic horizon. Soils with the similar xeric argialbolls classification are the Chicane, Kooskia, Nez Perce and Shebang series. Chicane and Kooskia soils have bisequa profiles. Nez Perce and Shebang soils have secondary lime at a depth of 20 to 30 inches.
GEOGRAPHIC SETTING: Lookingglass soils are on uplands at elevations of 1,800 to 4,000 feet. Slopes are 2 to 30 percent. The soils formed in loess and volcanic ash overlying older fine textured residuum or colluvium weathered from basalt. The climate is characterized by cool wet winters and hot dry summers. The mean annual precipitation is 17 to 30 inches. The mean annual temperature is 45 to 48 degrees F. The frost-free period is 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gwinly, Gelsinger (P), and Wolot soils. Gwinly soils are clayey-skeletal. Gelsinger (P) soils are well drained and lack an albic horizon. Wolot soils are ashy.
DRAINAGE AND PERMEABILITY: Moderately well drained; very slow permeability; a water table is present at 1.5 to 3.0 feet from March through April.
USE AND VEGETATION: These soils are used mainly for timber production. Cleared areas are cropped to small grains, hay, pasture, and peas. The native vegetation is ponderosa pine and Douglas fir with an understory of spirea, oceanspray, Idaho fescue, pinegrass and elksedge.
DISTRIBUTION AND EXTENT: Northeastern Oregon, MLRA 43. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Union County, Oregon, 1978.
REMARKS: This draft reflects a change in classification from xeric to xerertic argialbolls based on revisions to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon are:
mollic epipedon - from the surface to 11 inches (Ap, A horizons)
albic horizon - from 11 to 21 inches (E1 and E2 horizons)
argillic horizon - from 21 to 38 inches (2Bt1 and 2Bt2 horizons)
xerertic feature - from 21 to 38 inches (2Bt1 and 2Bt2 horizons) having montmorillonitic mineralogy, 35 to 50 percent clay, and high shrink swell.
particle-size control section - from 21 to 38 inches.