LOCATION GORDONPOINT UTEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Pachic Argiustolls
TYPICAL PEDON: Gordonpoint loam, on a 1 percent slope--rangeland (colors are for air-dry soil unless otherwise indicated).
A1--0 to 8 inches; brown (10YR 4/3) loam, very dark grayish brown (10YR 3/2) moist; weak granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine, very fine and few medium roots; common fine and very fine interstitial pores; 5 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (6 to 10 inches thick)
A2--8 to 18 inches; brown (7.5YR 4/2) clay loam, dark brown (7.5YR 3/2) moist; moderate medium and coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common fine, very fine and few medium roots, few fine and very fine interstitial pores; 5 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (10 to 13 inches thick)
Bt1--18 to 40 inches; brown (7.5YR 4/4) very gravelly clay loam, dark brown (7.5YR 3/4) moist; moderate fine subangular blocky structure; very hard, firm, sticky and plastic; few fine and medium roots; few fine and very fine interstitial pores; 35 percent gravel, 5 percent cobbles and 10 percent stones; neutral (pH 6.8); clear wavy boundary. (17 to 26 inches thick)
Bt2--40 to 60 inches; brown (7.5YR 5/4) very gravelly clay loam, brown (7.5YR 4/4) moist; strong coarse blocky structure; very hard, firm, sticky and plastic; few fine and very fine roots; few fine and very fine interstitial pores; 45 percent gravel, 10 percent stones; neutral (pH 6.8).
TYPE LOCATION: Kane County, Utah; about 4.5 miles south-southwest of the west shore of Navajo Lake, about 1,200 feet south and 1,900 feet east of the northwest corner of sec. 33, T. 38 S., R. 9 W. Straight Canyon Quadrangle. lat. 37 degrees 28 minutes 6 seconds N. and long. 112 degrees 51 minutes 30 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 40 to 45 degrees F. The mean summer soil temperature is 60 to 64 degrees F. The soil moisture control section is moist in some part for 70 to 85 percent of the time that the soil temperature is greater than 41 degrees F. It is not dry in all parts for as long as 45 days within the 4 months following the summer solstice. The soil moisture regime is typic ustic.
The mollic epipedon is 16 to 23 inches thick. Depth to bedrock and the combined thickness of the A and B horizons is greater than 60 inches. The particle-size control section averages 35 to 40 percent clay and 45 to 75 percent basalt rock fragments. Reaction is slightly acid to neutral throughout.
The A horizon has hue of 10YR to 5YR and dry chroma of 2 to 4. Texture of the fine earth is loam or clay loam with 5 to 20 percent gravel and cobbles.
The Bt horizon has hue of 7.5YR or 5YR, value of 4 or 5 dry and 3 or 4 moist, and chroma of 3 to 6. It contains 0 to 10 percent stones, 0 to 30 percent cobbles and 35 to 60 percent gravel. It has prismatic or blocky structure.
COMPETING SERIES: These are the Dalcan (UT), DesMoines (NM), Godding (CO) and Golime (CO) series. Dalcan soils have bedrock at a depth of 20 to 40 inches. DesMoines soils do not have 5YR and 7.5YR hues and have bedrock from 40 to 80 inches. Godding soils have rock fragments in the particle size control section that are more than 50 percent stones and boulders. Golime soils have calcic horizons.
GEOGRAPHIC SETTING: Gordonpoint soils are on volcanic flows on mountaintops at elevations of 7,200 to 8,300 feet. Slopes range from 1 to 10 percent. These soils formed in residuum from basalt. The mean annual air temperature is 39 to 44 degrees F. Average annual precipitation is 16 to 22 inches. The freeze-free period is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Seth and Syrett series. Seth soils are in a cryic temperature regime and have less than 35 percent rock fragments in the particle-size control section. They occur on moderately sloping mountainsides at higher elevations. Syrett soils do not have a pachic mollic epipedon and have less than 35 percent clay in the particle-size control section. They occur on steep to very steep mountainsides at lower elevations.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Used for rangeland and wildlife habitat. The native vegetation is low sagebrush, butterweed, daisy, yarrow, Letterman needlegrass, blue grama, bottlebrush squirreltail and Kentucky bluegrass.
DISTRIBUTION AND EXTENT: Southwestern Utah. These soils are not extensive. About 3,900 acres have been mapped in Kane County, Utah. MLRA 47.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Kane County (Iron-Washington Area), Utah, 1997. The series is named from a prominent ridgetop in the area.
REMARKS: The diagnostic features recognized in this pedon are:
Mollic epipedon - A zone of organic matter accumulation and high base saturation from the soil surface to a depth of about 18 inches (A horizons).
Pachic feature - The mollic epipedon is greater than 16 inches thick.
Argillic horizon - A zone of illuvial clay accumulation from a depth of 18 to 60 inches (Bt1 and Bt2 horizons).
Keys to Soil Taxonomy: Classified according to Eighth Edition, 1998.
ADDITIONAL DATA: