LOCATION GILT EDGE MTEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Torrertic Natrustalfs
TYPICAL PEDON: Gilt Edge silt loam - native grass. (Colors are for dry soil unless otherwise noted.)
A21--0 to 4 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist, pockets of very pale brown (10YR 7/3), grayish brown (10YR 5/2) moist; strong very thin platy structure parting to moderate very fine granular structure; soft, very friable; pockets and tongues of bleached grains throughout and bleached silt grains on undersides of plates; neutral (pH 6.5); clear boundary.
A22--4 to 5 inches; white (10YR 8/2) loam, light brownish gray (10YR 6/2) moist; strong very thin platy structure; soft, very friable; vesicular pores; clear mineral grains; neutral (pH 6.5); abrupt boundary.
B2t--5 to 13 inches; grayish brown (10YR 5/2) crushing to yellowish brown (10YR 5/4) clay, dark grayish brown (10YR 4/2) crushing to dark yellowish brown (10YR 4/4) moist; strong fine columnar structure in upper part separating with difficulty to weak fine angular blocky structure, moderate medium prismatic structure in lower part separating to strong medium blocky structure; extremely hard, very firm, very sticky, very plastic; tops of columns are rounded and coated with clear unstained mineral grains; faces of columns and blocks have shiny faces and are dark stained; moderately alkaline (pH 8.0); clear boundary. (6 to 10 inches thick.)
B3ca--13 to 19 inches; light olive brown (2.5Y 5/3) crushing to light yellowish brown (2.5Y 6/3) clay, olive brown (2.5Y 4/3) crushing to light olive brown (2.5Y 5/3) moist; moderate medium prismatic structure separating easily to strong medium angular blocky structure; extremely hard, firm, sticky, plastic; continuous dark stained light shiny faces on vertical faces and patchy on horizontal faces; slight effervescence, few soft bodies of lime; strongly alkaline (pH 8.6); diffuse boundary. (4 to 8 inches thick.)
C1ca--19 to 24 inches; olive (5Y 5/3) clay, olive (5Y 4/3) moist; weak coarse prismatic structure; extremely hard, firm, sticky, plastic; slight effervescence, few nodules of lime; strongly alkaline (pH 8.8); gradual boundary.
C2cacs--24 to 32 inches; light olive gray (5Y 6/2) clay, olive gray (5Y 4/2) moist; massive; extremely hard, friable, sticky, plastic; slight effervescence, few nodules of lime and streaks and bodies of gypsum; strongly alkaline (pH 8.8); diffuse boundary.
C3ca--32 to 40 inches; light brownish gray (2.5Y 6/2) light clay, olive brown (2.5Y 4/3) moist; massive; extremely hard, friable, sticky, plastic; few pebbles in lower part; slight effervescence; few bodies of gypsum; strongly alkaline (pH 8.6).
IIC4--40 to 60 inches; very gravelly loam in upper part becoming looser with depth. The pebbles have lime coats.
TYPE LOCATION: Treasure County, Montana; T. 7 N., R. 35 E., section 24, about 0.1 mile east of S 1/4 corner of section.
RANGE IN CHARACTERISTICS: The Gilt Edge soils are usually dry between depths of 4 and 12 inches when soil temperature is warmer than 41 degrees F., but they are not dry in all parts above 12 inches during this period for more than half the time. Mean annual soil temperature is more than 47 degrees F. Total thickness of the A2 horizon ranges from 5 to 8 inches. The Ap horizon has hue of 2.5Y through 7.5YR, value greater than 5 dry and greater than 3.5 moist, and chroma of 2 or 3. The surface layer is loam or silt loam. The B2t horizon has hue of 2.5Y through 7.5YR, value of 4 or 5, chroma of ped coats is 2 or 3 and of crushed peds mainly 3 or 4. The B2t horizon contains from 50 to 60 percent clay, dominantly of montmorillonitic type. It has columnar structure that can be broken with difficulty into fine blocks. It contains less than 15 percent exchangeable sodium and more exchangeable sodium plus magnesium than calcium plus hydrogen. In some pedons the Cca horizon is indistinct and contains only a few threads of lime. The C horizon has hue of 2.5Y or 5Y. Some part of the C horizon contains 15 percent or more exchangeable sodium. The IIC horizon of very gravelly loam is lacking in some pedons. Texture of the C horizon below the depth of 40 inches is not definitive for the series and any texture is permitted below this depth.
COMPETING SERIES: These are the Arvada, Round Butte, and Winnett series. All of these soils have more than 15 percent exchangeable sodium in the major part of the B2t horizon. The Round Butte soils, in addition, have soil temperatures of less than 47 degrees F.
SETTING: The Gilt Edge soils are on the nearly level, high terraces and on uplands underlain by bedrock. They formed in calcareous, alkaline clay. The climate is cool semiarid. Mean annual temperature ranges from 45 degrees to 49 degrees F., mean annual precipitation from 10 to 14 inches, and the freeze-free period from 95 to 120 days. Precipitation from April through October is 8 to 12 inches.
PRINCIPAL ASSOCIATED SOILS: These are the Allentine, Bew and Kyle series. The Allentine soils lack natric horizons and have blocky structure in the B2t horizon. The Bew and Kyle soils lack natric horizons. The Bew soils have distinct horizons and the Kyle soils lack distinct horizons.
DRAINAGE AND PERMEABILITY: Well drained. Subsoil permeability is slow to very slow.
USE AND VEGETATION: Used chiefly for native range. Some areas are farmed to small grains. Native vegetation is blue grama, Sandberg bluegrass and western wheatgrass.
DISTRIBUTION AND EXTENT: Gilt Edge series is of moderate extent in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Reconnaissance Soil Survey of Central Montana, 1946.
REMARKS: The Gilt Edge series was formerly classified in the Solonetz great soil group.
OSED scanned by SSQA. Last revised by state on 4/68.