LOCATION MARTINSON NVTentative Series
TAXONOMIC CLASS: Fine, smectitic, frigid Vitritorrandic Argixerolls
TYPICAL PEDON: Martinson gravelly ashy loam--rangeland. (Colors for dry soil unless otherwise noted).
A1--0 to 2 inches; grayish brown (10YR 5/2) gravelly ashy loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few coarse roots; many very fine and fine vesicular pores; slightly acid (pH 6.4); abrupt smooth boundary. (1 to 4 inches thick)
A2--2 to 4 inches; grayish brown (10YR 5/2) ashy loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine vesicular and few very fine tubular pores; neutral (pH 6.6); abrupt smooth boundary. (2 to 6 inches thick)
A3--4 to 7 inches; grayish brown (10YR 5/2) ashy clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure; soft, very friable, moderately sticky and moderately plastic; many very fine roots; many very fine and fine interstitial pores; neutral (pH 6.6); abrupt wavy boundary. (2 to 5 inches thick)
Bt1--7 to 12 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine roots; many very fine and fine interstitial pores; few faint clay films on faces of peds; neutral (pH 6.6); abrupt smooth boundary. (4 to 8 inches thick)
Bt2--12 to 18 inches; yellowish brown (10YR 5/4) clay, yellowish brown (10YR 5/6) moist; strong fine prismatic structure that grades to wedges; extremely hard, firm, very sticky and very plastic; many very fine roots between peds; common very fine tubular pores; common pressure cutans on faces of wedge-shaped peds; neutral (pH 7.0); clear smooth boundary. (6 to 10 inches thick)
Btss--18 to 24 inches; yellowish brown (10YR 5/4) clay, yellowish brown (10YR 5/6) moist; strong fine and medium angular blocky structure with some wedges present; extremely hard, very firm, very sticky and very plastic; no roots visible; few very fine tubular pores; common slickensides and pressure cutans on faces of wedge-shaped peds; brown (10YR 5/3) clay films on faces of peds; matrix is noneffervescent but effervescent in spots; slightly alkaline (pH 7.4); clear irregular boundary. (4 to 12 inches thick)
Crk--24 inches; variegated yellowish brown (10YR 5/4 and 10YR 5/6) weathered and fractured tuff; many fine white (10YR 8/1) coats of secondary carbonates in fractures.
TYPE LOCATION: Washoe County, Nevada; on the Sheldon National Wildlife Refuge about 1.5 miles south-southwest of Bald Mountain; about 450 feet north and 2,600 feet east of the southwest corner of section 16, T. 45 N., R. 21 E.; USGS Calcutta Lake 7.5 minute topographic quadrangle; 41 degrees 48 minutes 55 seconds north latitude and 119 degrees 37 minutes 36 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soils are usually moist in the moisture control section from mid-October to June, and are dry for more than 60 consecutive days between July and early October; Some areas receive additional moisture by lateral downslope movement of water above the bedrock contact; aridic moisture regime that borders on xeric.
Mean annual soil temperature - 44 to 46 degrees F.
Mean summer soil temperature - 60 to 62 degrees F.
Mollic epipedon thickness - 7 to 12 inches, includes the Bt1 horizon.
Depth to base of argillic horizon - 20 to 30 inches.
Depth to bedrock - 20 to 30 inches to a paralithic contact. The paralithic materials below the contact are weathered tuff.
Particle-size control section - Clay content: Averages 50 to 60 percent; Rock fragments: 0 to 10 percent, mainly pebbles. Lithology of fragments are volcanic rocks such as tuff or basalt.
A1 horizon - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Rock fragments: 5 to 25 percent pebbles.
Structure: Platy, subangular blocky, or granular.
Reaction: Slightly acid or neutral.
Organic matter content: 2 to 4 percent.
Volcanic glass content: 30 to 60 percent in coarse silt through fine sand fractions.
A2 and A3 horizons - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Ashy loam or ashy clay loam.
Clay content: 18 to 27 percent.
Structure: Platy, subangular blocky, or granular.
Reaction: Slightly acid or neutral.
Organic matter content: 2 to 4 percent.
Volcanic glass content: 30 to 60 percent in coarse silt through fine sand fractions.
Bt1 horizon - Hue: 7.5YR or 10YR.
Value: 4 or 5 dry.
Chroma: 2 or 3, dry or moist.
Texture: Clay loam or clay.
Clay content: 35 to 50 percent.
Rock fragments: 0 to 15 percent pebbles.
Structure: Subangular blocky or prismatic that grades to wedge-shaped peds with increasing clay content.
Organic matter content: 1 to 3 percent.
Bt2 horizon - Hue: 7.5YR or 10YR.
Value: 4 or 5 dry or moist.
Chroma: 4 through 6, dry or moist.
Clay content: 40 to 50 percent.
Rock fragments: 0 to 15 percent pebbles.
Structure: Subangular blocky or prismatic that grades to wedge-shaped peds with increasing clay content.
Other features: Pressure cutans are present on faces of peds.
Btss horizon - Hue: 7.5YR or 10YR.
Value: 4 or 5 dry or moist.
Chroma: 4 through 6, dry or moist.
Clay content: 50 to 70 percent.
Rock fragments: 0 to 5 percent pebbles.
Structure: Strong, fine to coarse, angular blocky that grades to wedge-shaped peds with increasing clay content.
Reaction: Slightly alkaline or moderately alkaline.
Slickensides: Small slickensides occur on faces of wedge-shaped peds.
Other features: Some pedons have few fine filaments of secondary carbonates.
COMPETING SERIES: At present, there are no other series in this family.
GEOGRAPHIC SETTING: Martinson soils are on plateaus. They typically occur on summit and shoulder positions. These soils formed in slope alluvium and residuum derived from tuff. Slopes are 4 to 30 percent. Elevations range from 6,000 to 7,300 feet. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 11 to 16 inches, mean annual temperature is 40 to 44 degrees F., and the frost-free period is 40 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hart Camp, Mosquet, Newlands, and Ninemile soils. Hart Camp soils are loamy and shallow to paralithic contacts. Mosquet and Ninemile soils are shallow to lithic contacts. Newlands soils are fine-loamy, deep to lithic contacts, and have a cryic temperature regime.
DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; slow permeability.
USE AND VEGETATION: Martinson soils are used for livestock grazing and wildlife habitat. The vegetation is mainly low sagebrush, Sandberg's bluegrass, Thurber's needlegrass, Idaho fescue, and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Northwestern Nevada. These soils are not extensive with a total of about 3,000 acres mapped to date. MLRA 23.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES PROPOSED: Washoe County (Massacre Area), Nevada, 1966. The name comes from a prominent spring in the area.
REMARKS: This revision of March 2001 updates the taxonomic classification from Fine, smectitic Natric Cryoborolls. A natric horizon is not present and mean summer soil temperatures are in the range of the frigid temperature regime. The presence of vitrandic intergrade properties and the volcanic glass content is estimated from similar soils in MLRA 23. This series may need a new type location and further revision in concept when the Sheldon National Wildlife Refuge is mapped in future years. The series should be dropped if it is not eventually used in a correlated soil survey.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 12 inches (A1, A2, A3, and Bt1 horizons).
Vitrandic intergrade feature - The zone from the soil surface to 7 inches (A1, A2, and A3 horizons).
Argillic horizon - The zone from 7 to 24 inches (Bt1, Bt2, and Btss horizons).
Slickensides - The zone from 18 to 24 inches (Btss horizon).
Paralithic contact - The boundary at 24 inches to underlying soft, weathered bedrock (Cr layer).
Particle-size control section - The zone from 7 to 24 inches (Bt1, Bt2, and Btss horizons).