LOCATION BROAD UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Calcic Argixerolls
TYPICAL PEDON: Broad gravelly loam--rangeland. (Colors are for air-dry soil unless otherwise stated.)
A1--1 to 3 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; weak fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; many fine and very fine roots; about 20 percent gravel; neutral (pH 7.2); clear smooth boundary. (3 to 5 inches thick)
A2--3 to 9 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine roots; about 20 percent gravel; neutral (pH 7.2); clear smooth boundary. (5 to 10 inches thick)
BA--9 to 12 inches; brown (10YR 4/3) gravelly clay loam, very dark brown (10YR 2/2) moist; weak fine and medium subangular blocky structure; hard, firm, slightly sticky and plastic; many fine and very fine roots; about 25 percent gravel and cobbles; mildly alkaline (pH 7.4); clear smooth boundary. (0 to 6 inches thick)
Bt1--12 to 22 inches; brown (10YR 5/3) gravelly clay loam, dark brown (7.5YR 4/2) moist; moderate medium subangular blocky structure; very hard, firm, sticky and plastic; common very fine roots; many thin clay films on faces of peds and in pores; about 25 percent gravel and cobbles; clear smooth boundary. (6 to 12 inches thick)
Bt2--22 to 28 inches; brown (7.5YR 5/4) very gravelly clay loam, dark brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; very hard, firm, sticky and plastic; common very fine roots; many thin clay films on faces of peds and in pores; about 55 percent gravel and cobbles; mildly alkaline (pH 7.8) gradual wavy boundary. (0 to 8 inches thick)
Bk--28 to 36 inches; very pale brown (10YR 8/3) extremely gravelly loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; about 65 percent gravel and cobbles; strongly calcareous; strongly alkaline (pH 8.6); abrupt smooth boundary. (3 to 13 inches thick)
R--36 inches; fractured sandstone bedrock.
TYPE LOCATION: Box Elder County, Utah; 4 miles northeast of Whites Valley; 200 feet west and 400 feet south of northeast corner, sec. 15, T. 13 N., R. 4 W.
RANGE IN CHARACTERISTICS: The mollic epipedon is 10 to 20 inches thick. Bedrock is at a depth of 20 to 40 inches. Coarse fragments are mainly gravel and cobble size angular sandstone, with some limestone and quartzite rock fragments. Secondary carbonate is at a depth of 17 to 36 inches. Coarse fragments generally increase in volume with depth ranging from 15 to 35 percent in the A horizon, 25 to 60 percent in the Bt horizon and 35 to 80 percent in the Bk horizon. Clay content of the particle size control section is 25 to 35 percent. A and B horizons are noncalcareous above the calcic horizon. The mean annual soil temperature at 20 inches is 44 to 47 degrees F, and the average summer temperature is 68 degrees F.
The A horizon has hue of 10YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 2 or 3. Rock fragment content is 15 to 35 percent. Reaction is neutral or moderately alkaline.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 to 6 dry, 3 or 4 moist, and chroma of 3 or 4. Rock fragment content is 25 to 60 percent. Texture is very gravelly clay loam, very cobbly clay loam, gravelly clay loam or cobbly clay loam. Reaction is mildly alkaline or moderately alkaline.
The Bk horizon has hue of 10YR or 7.5YR, value of 5 to 8 dry, 4 to 7 moist and chroma of 2 to 4. Rock fragment content is 35 to 80 percent. Texture is extremely gravelly loam, very cobbly loam or extremely cobbly loam. Clay content is 15 to 30 percent. Carbonate equivalent is 15 to 40 percent. Reaction is moderately alkaline or strongly alkaline.
COMPETING SERIES: These are the Amelar, Custco (T), Drage, Scalfar (T), Searla, Sheep Creek, Small, and Swampydraw (T) series. The Amelar, Custco, Drage, Scalfar, Searla, and Swampydraw soils are all more than 60 inches to bedrock. Sheep Creek have Bk horizons 13 to 22 inches from the surface. Small soils have a Bk horizon at 6 to 13 inches from the surface and mean annual soil temperature of 40 to 44 degrees F.
GEOGRAPHIC SETTING: The Broad soils are on steep to very steep north- and east-facing slightly concave mountainsides. Slopes range from 20 to 60 percent. They formed in residuum and colluvium derived mostly from sandstone but with some interbedded limestone and quartzite rocks. The climate is dry subhumid, with average annual precipitation of 12 to 19 inches. Mean annual temperature is 42 to 45 degrees F, and the freeze-free period is 70 to 115 days. Elevation ranges from 5,200 to 9,000 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Manila, Middle, Reywat, Sandall, Smarts and Yeates Hollow soils. Middle soils have mean annual soil temperatures of more than 47 degrees F. Manila soils have more than 35 percent clay and have less than 15 percent coarse fragments in the argillic horizon. Reywat soils are less than 20 inches deep to bedrock. Sandall soils lack mollic epipedons. Smarts soils have mollic epipedons more than 20 inches thick. Yeates Hollow soils have more than 35 percent clay in the argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used mainly for rangeland and watershed. Vegetation is bluebunch wheatgrass, Sandberg bluegrass, big sagebrush, yellowbrush, Gamble oak serviceberry, snowberry, cheatgrass, and annual weeds.
DISTRIBUTION AND EXTENT: Northwest Utah. These soils are moderately extensive. (30,000 acres mapped in East Box Elder) (50,000 acres mapped in Tooele Area)
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Northern Utah, Box Elder County, Utah, 1941.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon--the zone of dark colored soil material from the surface to a depth of 12 inches. (A1, A2, and BA horizons)
Argillic horizon--the zone of clay accumulation below the surface layer at depths of 12 to 28 inches. (Bt1 and Bt2 horizons)
Calcic horizon--the zone of carbonate accumulation at depths of 28 to 36 inches and above the bedrock. (Bk horizon)
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.