LOCATION FARLIN MT
Established Series
REV. KTS-GFB-EMM
04/2014
FARLIN SERIES
The Farlin series consists of very deep well drained soils that formed in alluvium, colluvium or slide deposits derived from limestone. These soils occur on fan remnants, hills, mountain slopes, ridges, escarpments, and landslides. Slopes are 2 to 60 percent. Mean annual precipitation is about 490 mm and mean annual air temperature is about 3 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, carbonatic Calcic Haplocryolls
TYPICAL PEDON: Farlin gravelly loam, in rangeland on a 36 percent slope at an elevation of 2283 meters (colors are for dry soil unless otherwise noted).
A--0 to 25 cm; very dark gray (10YR 3/1) gravelly loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many very fine and fine dendritic tubular pores; 15 percent gravel; neutral (pH 7.0); clear smooth boundary. (13 to 40 cm thick)
Bk1--25 to 46 cm; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, and few medium roots; many very fine tubular and irregular pores; 35 percent gravel and 5 percent cobbles; finely disseminated calcium carbonate, 5 percent soft masses of calcium carbonate, and 75 percent fine distinct irregular carbonate nodules on bottom of rock fragments; violently effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (13 to 50 cm thick)
Bk2--46 to 76 cm; light gray (2.5Y 7/2) very gravelly loam, grayish brown (10YR 5/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine irregular pores; 40 percent gravel and 10 percent cobbles; finely disseminated calcium carbonate, 10 percent soft masses of calcium carbonate, and 60 percent medium distinct irregular carbonate nodules on rock fragments; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (25 to 50 cm thick)
Bk3--76 to 152 cm; pale yellow (2.5Y 8/2) extremely gravelly fine sandy loam, light brownish gray (10YR 6/2) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; 50 percent gravel and 10 percent cobbles; finely disseminated calcium carbonate, 5 percent soft masses of calcium carbonate, and 60 percent medium distinct irregular carbonate nodules on rock fragments; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Beaverhead County, Montana; located about 200 feet east and 1300 feet south of the northwest corner of sec. 14 , T. 6 S., R. 12 W; Polaris topographic quadrangle; UTM 12T, 339455e, 5020389n, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 1 to 4 degrees C.
Mollic epipedon thickness - 18 to 40 cm and may include part of the Bk1 horizon
Depth to calcic horizon - 18 to 40 cm
Control section - averages more the 40 percent calcium carbonate by weight
Note: Some pedons may have a Bw horizon.
A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 1 to 3; dry or moist
Texture: silt loam or loam
Clay content: 18 to 27 percent
Rock fragments: 5 to 35 percent--5 to 30 percent gravel, 0 to 15 percent cobbles, 0 to 5 percent stones
Reaction: pH 6.6 to 7.6
Bk1 horizon
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 4 to 6 dry; 2 to 4 moist
Chroma: 2 or 3; dry or moist
Texture: loam or fine sandy loam
Clay content: 18 to 27 percent
Rock fragments: 25 to 60 percent--20 to 50 percent gravel, 0 to 15 percent cobbles and stones
Calcium Carbonate Equivalent: 15 to 50 percent (includes coarse fragments less than 20 mm in size)
Reaction: pH 7.9 to 8.4
Bk2 and Bk3 horizons
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 6 to 8 dry; 4 to 6 moist
Chroma: 2 to 4; dry or moist
Texture: loam or fine sandy loam
Clay content: 18 to 27 percent
Rock fragments: 35 to 70 percent--30 to 65 percent gravel, 5 to 25 percent cobbles and stones
Calcium Carbonate Equivalent: 40 to 60 percent (includes coarse fragments less than 20 mm in size)
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Hanson (MT) - have an udic moisture regime
Skaggs (MT) - is moderately deep to a lithic contact
GEOGRAPHIC SETTING:
Landform - fan remnants, hills, mountain slopes, ridges, escarpments, and landslides
Elevation - 1700 to 2745 meters
Slope - 2 to 60 percent
Parent material - alluvium, colluvium or slide deposits derived from limestone
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 380 to 610 mm
Mean annual air temperature - 1 to 4 degrees C.
Frost-free period - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Farlin soils are used mainly for rangeland. The vegetation is mainly bluebunch wheatgrass, Idaho fescue, kingspike fescue, POA (species), prairie junegrass, mountain big sagebrush, threetip sagebrush, rubber rabbitbrush, and other miscellaneous forbs.
DISTRIBUTION AND EXTENT: Farlin soils are of small extent in southwestern Montana. MLRAs - 43B, 44B, 46.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Horse Prairie-South Valley Area - Part of Beaverhead County, Montana, 2011; proposed in Beaverhead County, Montana, 2009.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 25 cm (A horizon)
Calcic horizon - from 25 to 152 cm (Bk1, Bk2 and Bk3 horizons)
Particle-size control section - from 25 to 100 cm (Bk1, Bk2 and part of Bk3 horizons)
Farlin soils have a cryic temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.