LOCATION FOYSLAKE MTTentative Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Glossic Hapludalfs
TYPICAL PEDON: Foyslake gravelly silt loam, forested. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 2 inches; slightly decomposed needles and twigs.
E--2 to 12 inches; light gray (2.5Y 7/2) gravelly silt loam, grayish brown (2.5Y 5/2) moist; weak fine and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many fine, medium and coarse roots; common fine dendritic tubular pores; 5 percent cobbles and 20 percent gravels; neutral (pH 6.9); clear smooth boundary. (4 to 15 inches thick)
Bt/E--12 to 21 inches; B part (about 60 percent) light yellowish brown (2.5Y 6/4) gravelly silt loam, light olive brown (2.5Y 5/4) moist; E part (40 percent) light yellowish brown (2.5Y 6/3) gravelly silt loam, light olive brown (2.5Y 5/3) moist, that interfingers into the B part; texture mixed is gravelly silt loam; weak medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common fine and medium roots; common fine dendritic tubular pores; few faint patchy clay films on faces of peds (B part); 5 percent cobbles and 25 percent gravel; neutral (pH 7.0); clear wavy boundary. (5 to 18 inches thick)
Bt--21 to 28 inches; light olive brown (2.5Y 5/4) very gravelly silty clay loam, olive brown (2.5Y 4/4) moist; weak medium subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common fine roots; few fine dendritic tubular pores; common distinct discontinuous clay films on faces of peds; 5 percent stones, 5 percent cobbles and 25 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (5 to 14 inches thick)
Bk--28 to 60 inches; light yellowish brown (2.5Y 6/3) very gravelly silt loam, light olive brown (2.5Y 5/4) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common fine roots; few fine dendritic tubular pores; 5 percent stones, 5 percent cobbles and 25 percent gravel; disseminated lime; many distinct lime coatings on undersides of rock fragments; strongly effervescent; moderately alkaline (pH 8.2);
TYPE LOCATION: Flathead County, Montana; 800 feet north and 1800 feet east of the SW corner of sec. 1, T. 27 N., R. 22 W. Blue Grass Ridge topographic quadrangle. UTM NAD 83 Zone 11: Northing 5333297, Easting 694974.
RANGE IN CHARACTERISTICS:
Soil temperature - 39 to 44 degrees F.
Moisture control section - between 4 and 12 inches.
Control section - 18 to 35 percent clay.
Rock fragments - 35 to 60 percent in the control section
Depth to carbonates 20 to 40 inches.
E horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Clay content: 8 to 18 percent
Rock fragments: 15 to 35 percent--0 to 10 percent cobbles and stones; 10 to 30 percent gravel
Reaction: pH 6.4 to 7.2
Bt/E horizon - Hue: B part 2.5Y or 10YR; E part 2.5Y or 10YR
Value: B part 5 or 6, E part 6 or 7 dry; B part 4 or 5, E part 4, 5 or 6 moist
Chroma: B part 3 or 4; E part 2 or 3
Texture (mixed): silt loam or loam
Clay content: 15 to 30 percent (increases with increasing depth) Rock fragments: 15 to 50 percent--0 to 15 percent cobbles and stones; 15 to 40 percent gravel
Reaction: pH 6.4 to 7.4
Bt horizon - Hue: 2.5Y or 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4
Texture: silt loam or silty-clay loam
Clay content: 18 to 35 percent
Rock fragments: 35 to 60 percent--0 to 20 percent cobbles and stones; 15 to 45 percent gravel
Reaction: pH 6.8 to 7.8
Bk horizon - Hue: 2.5Y
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2, 3, or 4
Texture: silt loam or loam
Clay content: 8 to 27 percent
Rock fragments: 35 to 60 percent--0 to 20 percent cobbles and stones; 15 to 45 percent gravel
Calcium Carbonate equivalent: 15 to 40 percent
Reaction: pH 7.8 to 8.6
COMPETING SERIES: These are the Grizzly, Pactola, and Rockoa series. These soils do not have calcic horizons.
GEOGRAPHIC SETTING: Foyslake soils are on moraines in glaciated valleys and on mountain slopes. Elevations are 2,900 to 5,200 feet. Slopes are 4 to 60 percent. Aspects are northerly, where shade minimizes evapotranspiration. These soils formed in calcareous till. The climate is characterized by long, cold winters; moist springs; and warm, dry summers. Mean annual precipitation is 19 to 30 inches, much of which falls as snow or as spring rain. Mean annual temperature is 38 to 44 degrees F. The frost-free period is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kingspoint, McMannamy, and Jimlake series. Kingspoint soils are on convex positions on south facing slopes. They are ustic, shallow to carbonates, and lack an argillic horizon. McMannamy soils are on concave and linear positions on southerly aspects, and convex positions on more shaded aspects. They are ustic and shallow to carbonates, but have a thin argillic horizon. Jimlake soils occur on concave, north sloping aspects above 4300 feet elevation. They generally have a thick ash mantle, cryic soil temperature regime, and are deep or very deep to carbonates.
DRAINAGE AND PERMEABILITY: Well drained and moderate permeability.
USE AND VEGETATION: Foyslake soils are used for timber production and wildlife habitat. The native vegetation is western larch, Douglas-fir, and scattered Engelmann spruce with an understory of twinflower, pinegrass, snowberry, dwarf huckleberry, and Rocky mountain maple.
DISTRIBUTION AND EXTENT: Foyslake soils are of small extent in northwestern Montana. MLRA 43A and 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Flathead County, Montana 2005. The name is from the Foys Lake area southwest of Kalispell in the Upper Flathead Valley of Northwest Montana.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 12 inches (Oi and E horizon);
Argillic horizon - from 12 to 28 inches, (lower half of Bt/E and all of Bt horizon);
Calcic horizon - at 28 inches (Bk horizon);
Particle-size control section - from 12 to 28 inches.
Foyslake soils have a frigid temperature regime and a udic moisture regime.