LOCATION SECREPASS NVEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Typic Palexerolls
TYPICAL PEDON: Secrepass gravelly loam, rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 40 percent pebbles and 5 percent with cobbles.
A1--0 to 3 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; weak thick platy parting to moderate fine subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, few fine and medium roots; common very fine and few fine interstitial pores; 25 percent pebbles; neutral (pH 6.8); clear smooth boundary. (2 to 5 inches thick)
A2--3 to 7 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; common very fine and few fine, medium and coarse interstitial and tubular pores; 15 percent pebbles; neutral (pH 6.8); abrupt smooth boundary. (4 to 8 inches thick)
Bt1--7 to 14 inches; brown (10YR 5/3) gravelly clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, sticky and plastic; common very fine and few fine and medium roots; many very fine and few fine and medium interstitial and tubular pores; common thin clay films on faces of peds and few thin lining pores; 25 percent pebbles, 5 percent cobbles; neutral (pH 6.6); abrupt smooth boundary. (5 to 8 inches thick)
2Bt2--14 to 23 inches; brown (10YR 5/3) very gravelly clay, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and few fine and medium roots; many moderately thick clay films on faces of peds and lining pores; 30 percent pebbles, 10 percent cobbles; neutral (pH 6.8); clear smooth boundary. (8 to 10 inches thick)
2Bt3--23 to 31 inches; dark yellowish brown (10YR 4/6) very gravelly clay, dark yellowish brown (10YR 4/6) moist; strong coarse prismatic prismatic parting to coarse angular blocky; hard, firm, very sticky and very plastic; few very fine to coarse roots; many very fine and few fine, medium and coarse tubular pores; many moderately thick clay films on faces of peds and lining pores; few pressure faces; 30 percent pebbles, 10 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (7 to 11 inches thick)
3C--31 to 60 inches; very pale brown (10YR 7/3) extremely gravelly sandy loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, very friable, slightly sticky and nonplastic; few very fine and fine roots; common very fine interstitial pores; 45 percent pebbles, 15 percent cobbles and 5 percent stones; slightly acid (pH 6.4).
TYPE LOCATION: Elko County, Nevada; Approximately 5 miles north of Arthur, Nevada; 600 feet south and 2400 feet west of the northeast corner of section 3, T. 34 N., R. 60 E., 115 degrees, 11 minutes, 20 seconds west longitude and 40 degrees, 51 minutes, 54 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist, moist in winter and spring, dry in late summer and fall.
Soil temperature - 44 to 47 degrees F.
Mollic epipedon thickness - 12 to 16 inches includes upper part of argillic horizon.
Depth to abrupt textural boundary - 7 to 10 inches.
Depth to base of argillic - 30 to 40 inches.
Reaction - Slightly acid or neutral.
Control section - Clay content: Averages 35 to 50 percent.
Rock fragments: Averages 35 to 60 percent.
A horizon - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3.
Bt horizon - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3.
Texture: Gravelly clay loam, very gravelly clay loam.
Clay content: 30 to 40 percent.
Rock fragments: 25 to 40 percent gravel, 0 to 5 percent cobbles.
2Bt horizons - Value: 4 or 5 dry.
Chroma: 3 through 6.
Texture: Very gravelly clay, very cobbly clay.
Clay content: 40 to 60 percent.
Rock fragments: 25 to 45 percent gravel and 5 to 15 percent cobbles.
Structure: Prismatic or subangular blocky.
Consistence: Slightly hard or hard dry, friable or firm moist, sticky or very sticky and plastic or very plastic wet.
Other features: Black (10YR 2/1) organic stains on ped faces and lining pores.
COMPETING SERIES: These are the Amboat (ID), Aninto (ID), Durfee (UT), Ebic (NV), Ziram (NV). Amboat soils have 60 to 85 percent stones in the Bt horizons and have a combined A and Bt thickness of 40 to more than 60 inches. Aninto soils have a combined A and Bt horizon thickness of more than 40 inches and have a 2Bk horizon. Durfee soils have a combined A and Bt horizon thickness of more than 60 inches, and clay content that does not decrease by as much as 20 percent of the maximum within 60 inches. Ebic soils are 20 to 30 inches to bedrock. Ziram soils have 7 to 11 inch thick mollic epipedons and are 16 to 27 inches to secondary carbonates,
GEOGRAPHIC SETTING: Secrepass soils are on fan piedmont remnants. These soils formed in mixed alluvium. Slopes are 4 to 15 percent. Elevations are 6200 to 7000 feet. The climate is cool, semiarid with cool moist winters and warm dry summers. The mean annual precipitation is 16 to 20 inches; Mean annual temperature is 40 to 44 degrees F., and the frost-free season is 80 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bullump, Cleavage, Krenka(T) and Welch series. Bullump and Krenka soils have mollic epipedons greater than 20 inches thick. Cleavage soils are shallow to bedrock. Welch soils are very poorly drained.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; very slow permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, Letterman needlegrass, Idaho fescue and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Northeast Nevada. MLRA 25. These soils are not extensive.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES PROPOSED: Elko County, Nevada, Southeast Part. 1992. The name is coined from Secret Pass.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the 0 to 14 inches (A1, A2 and Bt1 horizons).
Argillic horizon - The zone from 7 to 31 inches (Bt1, Bt2 and Bt3 horizons).
Abrupt Boundary - The zone at 7 inches (Abrupt boundary between A2 and Bt1 horizons).
Particle-size control section - The zone from 7 to 27 inches (Bt1, 2Bt2 and part of 2Bt3 horizons).