LOCATION CONNIEO MT
Established Series
Rev. DES-TJK-EMM
07/2012
CONNIEO SERIES
The Connieo series consists of shallow, well drained soils that formed in residuum from granite and other coarse grained igneous rocks. These soils are on escarpments, ridges, structural benches, and sideslopes of hills. Slopes are 2 to 60 percent. Mean annual precipitation is about 17 inches, and mean annual temperature is about 40 degrees F.
TAXONOMIC CLASS: Loamy, mixed, superactive, frigid Lithic Argiustolls
TYPICAL PEDON: Connieo sandy clay loam, bouldery in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 8 inches; dark grayish brown (10YR 4/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; many very fine and fine interstitial pores; 5 percent gravel; neutral (pH 7.2); clear smooth boundary. (4 to 8 inches thick)
Bt--8 to 14 inches; brown (10YR 5/3) gravelly sandy clay loam, brown (10YR 4/3) moist; weak medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, moderately sticky and slightly plastic; common very fine and few fine roots; many very fine and few fine pores; common faint clay films on faces of peds and bridging sand grains; 25 percent gravel; slightly alkaline (pH 7.6); clear smooth boundary. (5 to 14 inches thick)
Cr--14 to 18 inches; light brownish gray (2.5Y 6/2) decomposing granite bedrock (grus) which crushes to very gravelly loamy coarse sand or coarse sand. (2 to 8 inches thick)
R--18 inches; hard granite bedrock.
TYPE LOCATION: Jefferson County, Montana; 2,400 feet south and 100 feet west of the NE corner of sec. 11, T. 5 N., R. 4 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 38 to 44 degrees F.
Moisture control section - between 4 and 12 inches, or between 4 inches and bedrock if less than 12 inches.
Mollic epipedon thickness - 7 to 12 inches.
Depth to argillic horizon - 5 to 12 inches.
Depth to Cr horizon - 10 to 18 inches.
Depth to bedrock - 12 to 20 inches.
Surface stones or boulders - 0 to 15 percent.
A horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: coarse sandy loam, sandy loam, loam, or sandy clay loam
Clay content: 14 to 24 percent
Rock fragments: 5 to 70 percent; 0 to 15 percent stones and boulders, 0 to 15 percent cobbles, 5 to 50 percent gravel
Reaction: pH 6.1 to 7.6
Bt horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2, 3, or 4
Texture: sandy clay loam or clay loam
Clay content: 20 to 30 percent
Rock fragments: 10 to 35 percent total -- 10 to 35 percent gravel (mostly less than 7mm in diameter). Less commonly, some pedons have 0-5 percent cobbles and up to 20 percent stones.
Reaction: pH 6.1 to 7.8
Cr horizon - Reaction: pH 6.6 to 7.3
COMPETING SERIES:
Beje (UT) - does not have a paralithic contact above the lithic contact; formed in sandstone and shale.
Berland (NM) - does not have a paralithic contact over the lithic contact; is 6 to 10 inches deep to a lithic contact; has hue redder than 10YR in the control section.
Bonjea (WY) - does not have a paralithic contact above the lithic contact; is at elevations over 6,000 feet.
Cedric (MT) - has horizon of secondary carbonate accumulation; has less than 20 percent clay in the particle-size control section.
Coni (CO) - does not have a paralithic contact above the lithic contact; formed in arkosic material; has a lithic contact of tuff or conglomerate.
Kiln (NM) - has hue redder than 10YR in the argillic horizon.
Skyute (CO) - does not have a paralithic contact above the lithic contact.
Viewpoint (NM) - does not have a paralithic contact above a lithic contact; has a discontinuity in the argillic horizon.
GEOGRAPHIC SETTING:
Landform - escarpments, ridges, structural benches and sideslopes of hills.
Elevation - 4,400 to 6,000 feet.
Slope - 2 to 60 percent.
Parent material - residuum from granite and other coarse grained igneous rocks.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 15 to 19 inches.
Mean annual air temperature - 36 to 42 degrees.
Frost free season - 70 to 105 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Connieo soils are used mainly for rangeland. The potential native vegetation is Idaho fescue, bluebunch wheatgrass, rough fescue, Sandberg bluegrass, mountain big sagebrush, and rubber rabbitbrush. Areas with forest canopy have an overstory of Douglas-fir, limber pine, or ponderosa pine and an understory of Idaho fescue, bluebunch wheatgrass, or rough fescue.
DISTRIBUTION AND EXTENT: Connieo soils are of moderate extent in southwestern Montana. MLRA 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998.
REMARKS: Soil interpretation record: MT1560, MT3047, MT3048.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the soil surface to 8 inches (A horizon);
Argillic horizon - from 8 to 14 inches (Bt horizon);
Particle-size control section - from 8 to 14 inches (Bt horizon);
Paralithic contact - a layer of decomposed granite bedrock (grus) from 14 to 18 inches (Cr horizon);
Lithic contact - hard granite bedrock at 18 inches (R horizon).
Connieo soils have a frigid temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.