LOCATION RIDGECREST ID+WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, frigid Calcic Haploxerolls
TYPICAL PEDON: Ridgecrest gravelly loam - on a 22 percent southwest slope in rangeland at 6,200 feet elevation. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak very thin platy structure parting to weak very fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine interstitial pores; about 35 percent dark gray (N 4/) fine angular limestone gravel; strongly effervescent; few limestone fragments slightly coated with lime on lower side; neutral (pH 7.0); clear smooth boundary. (2 to 4 inches thick)
A2--2 to 7 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak very fine granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine and fine roots; common very fine tubular pores; about 40 percent fine angular limestone gravel; violently effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (2 to 14 inches thick)
Bk1--7 to 11 inches; grayish brown (10YR 5/2) very gravelly loam, light brownish gray (10YR 6/2) crushed, dark grayish brown (10YR 4/2) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; common very fine and fine and few medium roots; common very fine tubular pores; about 50 percent angular limestone gravel; 0.1 to 1 mm. lime coating on lower side of larger gravel; violently effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (4 to 8 inches thick)
Bk2--11 to 20 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 5/3) moist; massive; slightly hard, friable, slightly sticky, slightly plastic; few very fine to medium roots; few very fine tubular pores; about 70 percent dark gray (N 4/) angular limestone gravel and cobbles; 0.1 to 1 mm. lime coating on lower side of larger fragments; violently effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (6 to 15 inches thick)
Bk3--20 to 30 inches; very pale brown (10YR 7/3) very gravelly loam, brown (10YR 5/3) moist; massive; slightly hard, friable, slightly sticky, slightly plastic; few very fine and fine roots; few very fine tubular pores; about 60 percent dark gray (N 4/) angular limestone gravel and cobbles; 0.1 to 2 mm. lime coating and in places dark yellowish brown stains on larger fragments; violently effervescent; moderately alkaline (pH 8.0); abrupt irregular boundary. (2 to 19 inches thick)
R1--30 to 34 inches; dark gray (N 4/) fractured and slightly weathered limestone bedrock; some fragments coated in places with white carbonates and dark yellowish brown (10YR 4/4) stains. (1 to 10 inches thick)
R2--34 to 60 inches; dark gray (N4/) limestone bedrock.
TYPE LOCATION: Bingham County, Idaho; 100 feet east of Red road on side of ridge about 2 miles southeast of Wood Creek; southeast 1/4 of section. 33, T. 3 S., R. 38 E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 42 to 47 degrees F.
Calcium carbonate equivalent - more than 40 percent
Depth to lithic contact - 20 to 40 inches
Thickness of mollic epipedon - 7 to 16 inches
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Reaction - neutral through moderately alkaline
Effervescence - slight to strong
Bk horizon
Hue - 10YR through 2.5Y
Value - 5 through 8 dry, 3 through 6 moist
Chroma - 2 through 4 dry or moist
Reaction - mildly through strongly alkaline
Texture - STX-L, STX-SIL, GRV-L, CBV-SIL, CBV-L, CBV-SL, CBX-SL
Rock fragments - 50 to 90 percent
This horizon contains less than 5 percent soft powdery lime.
COMPETING SERIES: There are no other soils in this family. The Lizzant series is closely related but is very deep.
GEOGRAPHIC SETTING: Ridgecrest soils are on foothills and mountain slopes. Slopes range from 10 to 70 percent. They formed alluvium and colluvium derived dominantly from limestone. Average annual precipitation ranges from 12 to 18 inches. Average annual temperature ranges from 41 to 46 degrees F. Frost-free season is about 50 to 100 days. Elevation ranges from 4,500 to 7,000 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hymas, Ricrest, and Wahtigup soils. Hymas soils have limestone bedrock at 10 to 20 inches. Ricrest soils are fine-loamy and are very deep. Wahtigup soils have less than 35 percent rock fragments and are very deep. Hymas soils are on ridgetops. Ricrest soils are in concave positions on north-facing slopes. Wahtigup soils are in concave positions on south-facing slopes.
DRAINAGE AND PERMEABILITY: Well drained; runoff is medium to very rapid; permeability is moderate.
USE AND VEGETATION: This Ridgecrest soil is used mainly for rangeland. The potential natural vegetative is mainly mountains big sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Eastern Idaho and northern Utah. This series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Box Elder County, Utah, 1941.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 7 inches (A1 and A2 horizons)
Particle-size control section - The zone from 10 to 30 inches (part of the Bk1 horizon and the Bk2 and Bk3 horizons)
This series as mapped in Idaho; Power County Area, Ft. Hall Area, and Bannock County Area are Typic Calcixerolls. The official series type location is also a Typic Calcixeroll and the series should be reclassified. Follow-up with Wyoming and Utah are needed before reclassification.