LOCATION CURLEW MT
Established Series
Rev. EMR/JMS/RJS
07/2013
CURLEW SERIES
The Curlew series consists of very deep, very poorly drained soils that formed in alluvium. These soils are on flood plains and in drainageways. Slopes are 0 to 4 percent. Mean annual precipitation is about 330 mm, and mean annual temperature is about 6 degrees C.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Typic Endoaquolls
TYPICAL PEDON: Curlew silt loam, in pasture on a 1 percent slope at 1,053 meters elevation (colors are for moist soil unless otherwise noted).
Oe--0 to 8 cm; mucky peat; 10 percent gravel; slightly acid (pH 6.4); abrupt smooth boundary. (0 to 12 cm thick)
A--8 to 41 cm; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; moderate coarse granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and few medium roots; many fine tubular pores; 10 percent fine distinct strong brown (7.5YR 4/6) redox concentrations; 5 percent gravel; slightly acid (pH 6.4); abrupt smooth boundary. (28 to 38 cm thick)
C1--41 to 61 cm; dark grayish brown (10YR 4/2) gravelly sandy loam, light brownish gray (10YR 6/2) dry; massive; soft, very friable, nonsticky and nonplastic; common fine roots; common fine tubular and interstitial pores; 20 percent medium prominent yellowish brown (10YR 5/8) redox concentrations and 30 percent medium distinct dark gray (10YR 4/1) redox depletions; 17 percent gravel: neutral (pH 6.6); clear smooth boundary. (20 to 56 cm thick)
C2--61 to 152 cm; dark grayish brown (2.5Y 4/2) very gravelly sand, light brownish gray (2.5Y 6/2) dry; single grain; loose, nonsticky and nonplastic; many fine irregular and interstitial pores; 40 percent medium distinct yellowish brown (10YR 5/8) redox concentrations and 2 percent fine grayish brown (10YR 5/2) redox depletions; 40 percent gravel and 5 percent cobbles; neutral (pH 6.6)
TYPE LOCATION: Victor topographic quadrangle, Ravalli County, Montana; 765 meters north and 480 meters west of the SE corner of section 25, T. 8 N., R. 21 W. UTM Zone 11: 718072e, 5144739n, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C
Mollic epipedon thickness - 28 to 38 cm
Depth to seasonal high water table - 0 to 30 cm for extended periods during the year, often late spring or early summer
Depth to redox concentrations - 0 to 12 cm
Depth to redox depletions - 41 to 50 cm
A horizon
Value: 2 or 3 moist; 4 or 5 dry
Chroma: 1 or 2; dry or moist
Texture: silt loam or loam
Clay content: 10 to 20 percent
Rock fragments: 0 to 20 percent--0 to 15 percent gravel; 0 to 5 percent cobbles
Reaction: pH 6.0 to 7.4
C1 horizon
Value: 4 or 5 moist; 6 or 7 dry
Chroma: 1 to 3; dry or moist
Texture: sandy loam or fine sandy loam
Clay content: 8 to 18 percent
Rock fragments: 0 to 35 percent--0 to 35 percent gravel; 0 to 10 percent cobbles
Reaction: pH 6.4 to 7.4
C2 horizon
Hue: 2.5 Y or 10YR; dry or moist
Value: 4 to 6 moist; 6 or 7 dry
Chroma: 2 or 3; dry or moist
Texture: loamy sand, or sand
Clay content: 0 to 10 percent
Rock fragments: 35 to 65 percent--15 to 65 percent gravel; 0 to 20 percent cobbles
Reaction: pH 6.2 to 7.0
COMPETING SERIES:
Delamere (ND) - have a calcic horizon; do not have rock fragments; have a mollic epipedon thickness greater than 38 cm
Forada (MN+WI) - have horizons of strong gleying throughout the subsoil; have carbonates at depths of 50 to 150 cm
Meadowlands (MN) - have a cambic horizon; have a horizon of strong gleying; have carbonates at depths of 50 to 120 cm; do not have rock fragments
Runeberg (MN) - have horizons of strong gleying throughout the subsoil; have carbonates at depths from 43 to 91 cm
Skunkcreek (MN) - have a cambic horizon; have horizons of strong gleying throughout the subsoil; have carbonates at depths from 100 to 127 cm; do not have rock fragments
Tiffany (ND+SD) - have carbonates at depths from 50 to 127 cm; do not have rock fragments
GEOGRAPHIC SETTING:
Landform - flood plains and drainageways
Elevation - 900 to 1,440 meters
Slope - 0 to 4 percent
Parent material - alluvium
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 305 to 432 millimeters
Mean annual air temperature - 4 to 7 degrees C
Frost-free period - 80 to 115 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Very poorly drained; moderate permeability to a depth of 41 cm and moderately rapid and very rapid below.
USE AND VEGETATION: Curlew soils are used mainly for pasture and hayland. Vegetation is mainly mannagrass, tufted hairgrass, willow, and mountain rush.
DISTRIBUTION AND EXTENT: Curlew soils are of small extent in mountain valleys of western Montana. MLRA 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Bitterroot Valley Area, Montana, 2013; proposed in Ravalli County, Montana, 2009.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the 8 to 41 cm (A horizon)
Redox features - from 8 to 152 cm (A, C1, and C2 horizons)
Particle-size control section - from 33 to 108 cm (part of the A, C1, and C2)
Curlew soils have a frigid temperature regime and an aquic moisture regime.
National Cooperative Soil Survey
U.S.A.