LOCATION YURM NVEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic, shallow Calcic Petrocalcids
TYPICAL PEDON: Yurm gravelly sandy loam rangeland. (Colors are for dry soil unless otherwise noted.) About 80 percent of the soil surface is covered with pebbles and 5 percent with cobbles.
A1--0 to 1 inch; light gray (10YR 7/2) gravelly sandy loam, brown (10YR 5/3) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; 20 percent pebbles; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (1 to 3 inches thick)
A2--1 to 3 inches; light gray (10YR 7/2) gravelly loam, pale brown (10YR 6/3) moist; strong medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine vesicular pores; 25 percent pebbles; violently effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (1 to 3 inches thick)
Bk1--3 to 12 inches; light yellowish brown (10YR 6/4) very gravelly sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, firm, slightly sticky and moderately plastic; many very fine and common fine roots; few very fine interstitial pores; 40 percent pebbles and pan fragments; rock fragments coated with lime; violently effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (5 to 9 inches thick)
Bk2--12 to 16 inches; very pale brown (10YR 7/4) very gravelly sandy loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; many very fine, common fine and medium roots; few very fine interstitial and tubular pores; 50 percent pebbles and pan fragments; rock fragments are coated with lime; violently effervescent; strongly alkaline (pH 8.5); abrupt wavy boundary. (3 to 5 inches thick)
Bkm--16 to 61 inches; white (10YR 8/1) gravelly very strongly cemented petrocalcic horizon with accessory silica, very pale brown (10YR 8/2) moist; massive; very hard; violently effervescent.
TYPE LOCATION: Nye County, Nevada; approximately 5 miles south of the town of Mercury, about 2,600 feet south and 2,600 feet east of the northwest corner of Section 1, T. 16 S., R. 53 E.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry, moist for short periods during the winter month and spring, Typic Aridic moisture regime. The ratio of soil moisture utalized for evapotranspiration between summer and winter is about 0.4:1, typical of the Mojave Desert.
Soil temperature - 64 to 70 degrees F.
Depth to petrocalcic horizon - 10 to 20 inches.
Control section - Clay content: 5 to 15 percent.
Rock fragments: Averages 35 to 50 percent by volume.
A horizon - Value: 6 or 7 dry, 4 through 6 moist.
Chroma: 2 through 4 dry or moist.
Bk horizon - Value: 6 through 8 dry, 5 through 8 moist.
Chroma: 3 or 4 dry or moist.
Texture of fine earth: Fine sandy loam or sandy loam.
Structure: Subangular blocky or is massive.
Reaction: Moderately alkaline or strongly alkaline.
Other features: Some pedons contain pan fragments.
Bkm horizon - Cementation: Very strongly cemented and indurated; subhorizons are strongly cemented in some pedons.
Thickness: 3 to 10 feet.
COMPETING SERIES: These are the Boludo (TX), Cheosa (TX) and Winkel (UT). The Boludo and Cheosa soils have hard bedrock within 10 to 20 inches. The Winkel soils formed in residuum from basalt and limestone and rock fragments are dominated by caliche fragments.
GEOGRAPHIC SETTING: Yurm soils are on crests and shoulders of ballenas and on summits and side slopes fan piedmont remnants. These soils formed in alluvium primarily from quartzite and limestone. Slopes are 0 to 8 percent. Elevations are 2,400 to 4,200 feet. The climate is arid with hot summers and mild winters, typic of the Mojave Desert. The mean annual precipitation is between 3 and 6 inches; mean annual temperature is 63 to 68 degrees F.; and the frost-free season is 200 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Canutio soils. The Canutio soils lack petrocalcic horizons.
DRAINAGE AND PERMEABILITY: Well drained. Medium runoff; moderately rapid permeability above the petrocalcic horizon.
USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly creosotebush, white bursage and yucca.
DISTRIBUTION AND EXTENT: Southern Nevada. These soils are not extensive. MLRA 30.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Nye County, Nevada (Southwest Part). 1994. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 7 inches (A1, A2 and part of the Bk1 horizon)
Calcic horizon - The zone from about 3 to 16 inches (Bk1 and Bk2 horizon)
Petrocalcic horizon - The zone from about 16 to 60 inches (Bkm horizon)
Textural control section - The zone from 10 to 16 inches.