LOCATION GERMANGULCH        MT  
Established Series
JMS/EMM/RJS
01/2007

GERMANGULCH SERIES


The Germangulch series consists of moderately deep, well drained soils that formed in colluvium from rhyolite and other moderately fine-grained igneous rocks mixed with volcanic ash in the surface. These soils are on mountains, hills and ridges. Slopes are 4 to 60 percent. Mean annual precipitation is about 432 millimeters and mean annual air temperature is about 3 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive Vitrandic Haplocryalfs

TYPICAL PEDON: Germangulch cobbly ashy sandy loam, in rangeland on a 52 percent slope at 1,951 meters elevation (colors are for dry soil unless otherwise indicated).

Oi--0 to 3 cm; slightly decomposed forest litter.

E--3 to 23 cm; pale brown (10YR 6/3) cobbly ashy sandy loam, brown (10YR 4/3) moist; weak fine granular structure; very friable, slightly hard, slightly sticky and slightly plastic; common fine roots; many fine interstitial and irregular pores; 10 percent gravel, 10 percent cobbles, 2 percent stones; slightly acid (pH 6.2); clear wavy boundary. (10 to 25 cm thick)

Bt--23 to 58 cm; pale brown (10YR 6/3) cobbly sandy clay loam, brown (10YR 5/3) moist; weak medium prismatic structure; friable, hard, moderately sticky and moderately plastic; common fine roots; common fine tubular pores; common distinct clay films on ped faces; 10 percent gravel, 10 percent cobbles; neutral (pH 6.6); clear wavy boundary. (15 to 50 cm thick)

BC--58 to 84 cm; light yellowish brown (2.5Y 6/3) gravelly sandy loam, light olive brown (2.5Y 5/3) moist; weak medium subangular blocky structure; friable, hard, slightly sticky and slightly plastic; few very fine roots; common fine irregular pores; 15 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (10 to 45 cm thick)

Cr--84 cm; weakly cemented tuffaceous rhyolite.

TYPE LOCATION: Ramsay topographic quadrangle, Silver Bow County, Montana; 730 meters north and 475 meters west of the SE corner of section 14, T. 4 N., R. 14 W. UTM Zone 12: 370142e, 5106236n, NAD 83.

RANGE IN CHARACTERISTICS:
Soil temperature - 2 to 6 degrees C
Moisture control section - 10 to 30 cm
Depth to bedrock - 50 to 100 cm
Surface fragments - 0 to 15 percent stones

E horizon
Hue: 7.5YR or 10YR
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture: ashy loam or ashy sandy loam
Clay content: 12 to 26 percent
Volcanic glass content - 5 to 30 percent in the 0.02 to 2.0 mm size fraction
Ammonium oxalate extractable Al plus 1/2 Fe - 0.1 to 1.0 percent
Rock fragments: 10 to 30 percent--5 to 25 percent gravel, 0 to 5 percent cobbles, 0 to 5 percent stones
Reaction: pH 5.6 to 7.3

Bt horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: sandy clay loam, clay loam or loam
Clay content: 20 to 33 percent
Rock fragments: 10 to 30 percent--5 to 25 percent gravel, 0 to 10 percent cobbles, 0 to 2 percent stones
Reaction: pH 5.6 to 7.3

BC horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: sandy loam or loam
Clay content: 10 to 20 percent
Rock fragments: 25 to 45 percent--25 to 40 percent gravel; 0 to 5 percent cobbles
Reaction: pH 5.6 to 7.8

COMPETING SERIES:
Culdecole (ID) - is deep to a lithic contact.
Hopburn (ID) - is very deep.
Oleo (ID) - is very deep.
Vitroff (MT) - is very deep.

GEOGRAPHIC SETTING:
Landform - mountain slopes, mountain ridges and hills
Elevation - 1,560 to 2,215 meters
Slope - 4 to 60 percent
Parent material - colluvium derived from rhyolite, rhyodacite, or rhyolitic tuff
Climate - long, cold winters; cold, moist springs; short, cool summers
Mean annual precipitation - 330 to 483 millimeters, much of which falls as snow and as spring rain
Mean annual air temperature - 1 to 5 degrees centigrade
Frost-free period - 30 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Eastridge, Evaro and Vitroff soils which occur on similar landforms. Eastridge, Evaro and Vitroff soils are very deep.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.

USE AND VEGETATION: Germangulch soils are used for watershed, woodland and understory grazing. Native vegetation is mainly Douglas fir, lodgepole pine, pinegrass, elk sedge, Idaho fescue, rough fescue, kinnikinnick, oregongrape, woods pussytoes and common juniper.

DISTRIBUTION AND EXTENT: Germangulch soils are of small extent in the intermontane basins of central Montana. MLRA 43B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.

SERIES ESTABLISHED: Silver Bow County, Montana, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 23 cm (Oi and E horizons)
Argillic horizon - from 23 to 58 cm (Bt horizon)
Particle-size control section - from 18 to 58 cm(Bt horizon)
Vitrandic feature - from 0 to 23 inches (E horizon)

Germangulch soils have a cryic temperature regime and an ustic moisture regime.


National Cooperative Soil Survey
U.S.A.