LOCATION ROCKABIN NVEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Haplocryolls
TYPICAL PEDON: Rockabin very gravelly coarse sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.) The surface is covered by approximately 5 percent stones, l5 percent cobbles and 30 percent pebbles.
Al--0 to 2 inches; grayish brown (l0YR 5/2) very gravelly coarse sandy loam, very dark grayish brown (l0YR 3/2) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine interstitial pores; 60 percent pebbles; slightly acid (pH 6.4); clear smooth boundary. (l to 4 inches thick)
A2--2 to 8 inches; brown (l0YR 5/3) very gravelly coarse sandy loam, dark brown (l0YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; common very fine interstitial pores; 60 percent pebbles; neutral (pH 6.6); clear smooth boundary. (4 to l0 inches thick)
Cl--8 to l7 inches; pale brown (l0YR 6/3) very gravelly coarse sandy loam, brown (l0YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine tubular and few very fine interstitial pores; 55 percent pebbles; neutral (pH 6.6); clear smooth boundary. (7 to l5 inches thick)
C2--l7 to 2l inches; pale brown (l0YR 6/3) extremely gravelly sandy loam, brown (l0YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine tubular and few very fine interstitial pores; 70 percent pebbles; neutral (pH 6.7); abrupt wavy boundary. (0 to l6 inches thick)
Cr--2l inches; fractured altered granite bedrock.
TYPE LOCATION: Mineral County, Nevada, in the Wassuk range, approximately 2,400 feet north and 1,900 feet east of the southwest corner of section 22, T. ll N., R. 28 E.; 38 degrees, 47 minutes, 58 seconds north latitude, 118 degrees, 50 minutes, 40 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in winter and spring and early summer, dry summer and fall but moist intermittently due to convection storms. Dry in all parts for at least 45 consecutive days following the summer solstice.
Soil temperature - 44 to 47 degrees F.
Average summer soil temperature - 54 to 59 degrees F.
Thickness of mollic epipedon - 8 to l4 inches.
Depth to weathered bedrock - 20 to 40 inches.
Control section - Percent clay: l0 to l8 percent.
Rock fragments: Average 35 to 60 percent pebbles more than 50 percent 2 to 5 millimeters in size. Individual horizons may have up to 70 percent pebbles.
Sand fraction: Dominated by coarse sand.
A horizon - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3 dry or moist.
Reaction: Slightly acid to neutral.
C horizon - Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 or 3 dry or moist.
COMPETING SERIES: These are the Antrobus, Brickel, Broad Canyon, Decram, Fairydell, Farlow, Foxmount, Grafen, Greyback, Handran, Kamack, Klug, Lag, Maurice, McCort, Midelight, Midfork, Parachute, Sebud, Silvercliff, Sup, Supervisor, Teemat, Thornburgh, Tibanand Tineman series. Antrobus, Broad Canyon, Fairydell, Farlow, Greyback, Handran, Kamack, Klug, Lag, Maurice, McCort, Midelight, Midfork, Sebud, Silvercliff, Sup, Teemat, Thornburgh, Tiban, and Tineman soils have bedrock at depths greater than 40 inches. Brickel, Foxmount, Grafen and Supervisor soils have more rock fragments in the greater than 3 inch range, have more than 50 percent of the pebble size fragments are 5 millimeter to 3 inch and the sand fraction is dominated by medium sand and finer, Foxmount soils also have a mean annual soil temperature of 39 to 42 degrees. Parachute and Decram soils have over l8 percent clay in their control section. Supervisor soils also have hard bedrock at depths of 20 to 40 inches.
GEOGRAPHIC SETTING: Rockabin soils are on mountain side slopes and shoulders. These soils formed in residuum and colluvium from granitic rock. Slopes are l5 to 75 percent. Elevations are 8,000 to l0,500 feet. The climate is cool, continental with warm, dry summers and cold, moist winters. The average annual precipitation is about l2 to l4 inches; average annual air temperature is 42 to 44 degrees F., and the frost-free season is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hiridge and Snopoc series. Hiridge soils have an argillic horizon. Snopoc soils are mare than 40 inches deep to bedrock anf have a mollic epipedon over 16 inches thick.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, prairie Junegrass, phlox, Indian ricegrass, Sandberg bluegrass, and some desert bitterbrush.
DISTRIBTUION AND EXTENT: West central Nevada. these soils are not extensive.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES PROPOSED: Mineral County Area Nevada, l983.
REMARKS: The name is from a local mine.
DIAGNOSTIC HORIZONS AND FETURES RECOGNIZED IN THIS PEDON ARE:
Mollic epipedon - The zone from the surface to about 8 inches (A1, A2 horizons)
Paralithic contact - The boundary at about 21 inches (Cr horizon)
Particle-size control section - The zone from about 10 to 21 inches. (C1, C2 horizons)