LOCATION GATEWAY CO WYEstablished Series
TAXONOMIC CLASS: Fine, smectitic Eutric Glossocryalfs
TYPICAL PEDON: Gateway loam. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inches; slightly decomposed needles and twigs. (1 to 2 inches thick)
A--1 to 4 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist: weak medium granular structure; soft very friable, nonsticky and nonplastic; neutral (pH 6.7); clear smooth boundary. (0 to 4 inches thick)
E--4 to 9 inches; light gray (10YR 7/2) loam, brown (10YR 5/3) moist; moderate medium platy structure parting to weak medium granular; slightly sticky and slightly plastic; neutral (pH 6.7); clear smooth boundary. (2 to 5 inches thick)
B/E--9 to 13 inches; B part: brown (7.5YR 5/4) clay loam, brown (7.5YR 5/3) moist; E part: light gray (10YR 7/2) stains in the upper part of horizon; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many faint clay films on faces of peds; neutral (pH 6.7); gradual smooth boundary. (2 to 6 inches thick)
Bt1--13 to 24 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/3) moist; moderate and strong medium angular blocky structure; hard, firm, moderate sticky and moderately plastic; many distinct clay films on faces of peds; neutral (pH 6.7); gradual wavy boundary.
Bt2--24 to 31 inches; brown (7.5YR 5/4) parachannery clay loam, brown (7.5YR 5/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common faint clay films of faces of peds; 30 percent mudstone parachanners; neutral (pH 6.7); gradual wavy boundary. (combined thickness of the Bt horizons is 15 to 25 inches thick)
Cr--31 inches; soft, white mudstone of the Troublesome formation.
TYPE LOCATION: Grand County, Colorado, about 4 miles east of Fraser, 1,620 feet east and 500 feet south of the northwest corner of section 16, T. 1 S., R. 75 W.
RANGE IN CHARACTERISTICS: (Depths are measured from the top of the mineral soil surface.)
Soil moisture: The soil moisture control section is affected by precipitation that is evenly distributed throughout the year with the exception of peaks in the spring and later summer. Udic moisture regime.
Mean annual soil temperature: 36 to 43 degrees F
Mean summer soil temperature: 39 to 46 degrees F
Depth to paralithic contact: 20 to 40 inches to mudstone or shale
Depth to glossic horizon: 3 to 11 inches
Particle-size control section (weighted average):
Clay content: 35 to 45 percent
E horizon:
Hue: 7.5YR to 2.5Y
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 to 4 dry or moist
Clay content: 20 to 27 percent
Rock fragments: 0 to 30 percent gravel sized fragments of sedimentary origin
Reaction: moderately acid or neutral
Bt horizon:
Hue: 7.5YR to 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6 dry or moist
Texture: clay, clay loam, silty clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 30 percent gravel sized fragments of sedimentary origin
Pararock fragments: 5 to 35 percent mudstone or shale parachanners immediately above the paralithic contact
Reaction: slightly acid or neutral
COMPETING SERIES:
Muggins soils: very deep
GEOGRAPHIC SETTING:
Parent material: loamy slope alluvium over clayey residuum derived from mudstone or shale
Landform: mountain slopes
Slopes: 6 to 50 percent
Elevation: 8,000 to 10,000 feet
Mean annual temperature: 33 to 40 degrees F
Mean annual precipitation: 26 to 35 inches
Precipitation pattern: mostly even distribution with peaks in the spring and late summer
Frost-free period: 30 to 60 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cebona, Cimarron, and Cowdrey soils series. The Cebona soils do not have glossic horizons and are on similar landforms. The Cimarron and Cowdrey soils are very deep and are on mountain sides and fans.
DRAINAGE AND PERMEABILITY: Well drained, moderate runoff, slow permeability.
USE AND VEGETATION: Major uses are timber production and wildlife habitat. The central vegetative concept is subalpine vegetation with the dominant trees being Englemann's spruce, subalpine fir, and lodgepole pine with an understory of dwarf blueberry, heartleaf arnica, elk sedge, oregon grape, common juniper, and kinnikinnick.
DISTRIBUTION AND EXTENT: Subalpine zone of the Central Rocky Mountains in Colorado and Wyoming, LRR E, MLRA 48A; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Mesa County, Lower Colorado Area soil survey, Colorado, 1970.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 9 to 29 inches. (B/E, Bt1, Bt2 horizons)
Ochric epipedon: The zone from 0 to 9 inches. (A and E horizons)
Glossic horizon: The zone from 9 to 13 inches. (B/E horizons)
Argillic horizon: The zone from 9 to 29 inches. (B/E, Bt1, Bt2 horizons)
Paralithic contact: The contact with mudstone 31 inches. (Cr layer horizons)
The type location is being moved to the Grand County Area, Colorado type location to better reflect the series concept, Jan. 2000. In addition, the classification is being updated to Ustic Glossocryalfs from Typic Cryoboralfs. The central concept is now narrowed to subalpine vegetation (Englemann's spruce, subalpine fir, and lodgepole pine). Areas previously identified as Gateway whose dominant vegetation is ponderosa pine should be excluded from the current concept for the Gateway series.
4/2001 classification was changed from Ustic to Eutric Glossocryalfs. Precipitation was narrowed to exclude the less than 26 inches to limit this series to the typic-udic moisture regime.
Taxonomic version: Eighth Edition, 1998.