LOCATION STANBRO ORTentative Series
TAXONOMIC CLASS: Loamy, mixed, euic Terric Cryohemists
TYPICAL PEDON: Stanbro mucky peat, wet meadow on a 1 percent slope at elevation of 5,110 feet. (When described on June 9, 2002, the soil was wet throughout and the water table was at 4 inches. The lower part of the profile was described using auger borings due to standing water. Lower rock fragments based on an adjacent, well drained pedon. Colors are for moist soil unless otherwise noted.)
Oe1--0 to 11 inches; very dark gray (10YR 3/1) mucky peat with plant fibers that are very dark gray (10YR 3/1) dry; many very fine and fine and common medium roots; slightly acid (pH 6.4); clear smooth boundary.
Oe2--11 to 32 inches; black (7.5YR 2.5/1) mucky peat with plant fibers that are very dark gray (10YR 3/1) dry; many very fine and fine and common medium roots; slightly acid (pH 6.4); clear smooth boundary. (The combined thickness of the Oe horizon is 16 to 32 inches.)
2A--32 to 38 inches; greenish black (10Y 2.5/1) mucky silt loam, gray (10YR 5/1) dry; few plant remains, mostly sedges and rushes; massive; slightly hard, very friable, slightly sticky and slightly plastic; few very fine and fine roots; slightly acid (pH 6.4); clear smooth boundary. (0 to 10 inches thick)
2C1--38 to 44 inches; dark gray (2.5Y 4/1) gravelly clay loam, gray (10YR 6/1) dry; massive; slightly hard, friable, moderately sticky and moderately plastic; 20 percent gravel; neutral (pH 7.2); clear smooth boundary. (6 to 10 inches thick)
2C2--44 to 60 inches; dark grayish brown (2.5Y 4/2) very gravelly clay loam, gray (10YR 6/1) dry; massive; hard, firm, moderately sticky and moderately plastic; common very fine tubular pores; 30 percent gravel and 10 percent cobbles; neutral (pH 7.2).
TYPE LOCATION: Grant County, Oregon, in Logan Valley, about 25 miles southeast of John Day and about 20 miles east of Seneca, Oregon, 700 feet east and 1,950 feet south of the NW corner of section 13, T. 16 S., R. 33 1/2 E. (Latitude 44 degrees, 11 minutes, and 14 seconds North and Longitude 118 degrees, 36 minutes, and 09 seconds West)
RANGE IN CHARACTERISTICS: Thickness of O horizon and depth to the mineral layer is 16 to 32 inches. The rubbed fiber content is about 20 to 50 percent. The mean annual soil temperature is 38 to 42 degrees F. Mean summer soil temperature is about 56 degrees F. Depth to high water table fluctuates from 6 inches above the surface to 1.5 feet below the surface from January to December.
The Oe horizon has hue of 10YR through 5Y, or neutral, value of 1 through 3 moist or dry, and chroma is 0 to 2 moist or dry.
The 2A horizon, when present, is mucky silt loam with 18 to 27 percent clay.
The 2C horizon is gravelly clay loam, gravelly loam, or very gravelly clay loam. It has 20 to 35 percent clay and more than 35 percent sand. It has 0 to 10 percent cobbles and 20 to 40 percent gravel.
COMPETING SERIES: These are the Doroshin, Hewitt, and Tepete series. Doroshin soils have the mineral layer consisting of lacustrine deposits with texture mostly silt loam with less than 18 percent clay. Hewitt soils have the mineral layer consisting of silt loam or silty clay loam with no rock fragments. Tepete soils have continuous layers of loamy sand and sand in the lower part of the control section.
GEOGRAPHIC SETTING: Stanbro soils are on fens in swales, basins, or slight depressions in mountain meadows. Slopes range from 0 to 2 percent. Elevation ranges from about 5,000 to 6,000 feet. The soil formed in material from decomposing sedges and rushes over glaciofluvial deposits. The mean annual precipitation is 20 to 36 inches. The mean annual air temperature is 36 to 43 degrees F., and the mean summer temperature is about 57 degrees F. The frost-free period is 10 to 30 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Frenchcabin, Loganvalley, Magill, Starglade, and Weberg soils, all of which are mineral soils. Frenchcabin soils are fine-silty over sandy or sandy-skeletal, somewhat poorly drained, and are on convex positions within mountain meadows. Loganvalley soils are loamy-skeletal, well drained, and are on fan remnants. Magill and Starglade soils are well drained, loamy-skeletal, and are on hills. Furthermore, Magill soils are moderately deep to igneous bedrock whereas Starglade soils are very shallow to the same bedrock. Weberg soils are loamy-skeletal, moderately well drained, and are on glacial outwash plains.
DRAINAGE AND PERMEABILITY: Very poorly drained; very slow runoff or ponded; rapid permeability in the organic layer and moderately slow in the mineral material.
USE AND VEGETATION: Used mainly for pasture. The native vegetation is sedges and rushes; ecological site is Meadow Fen R010XY032OR.
DISTRIBUTION AND EXTENT: East central Oregon, MLRA 10. The soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Grant County Area, Oregon, 2003.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Organic layer - the zone from the surface to 32 inches (the Oe1 and Oe2 horizons)
Mineral layer - the zone from 32 to 60 inches (the 2A, 2C1, and 2C2 horizons)
Soil moisture regime - aquic.