LOCATION LOOMIS NV+CA ID

Established Series
Rev. JVC-JBF
04/2019

LOOMIS SERIES

The Loomis series consists of very shallow and shallow, well drained soils that formed in colluvium and residuum derived from volcanic and sedimentary rocks. Loomis soils are on rock pediments, plateaus, structural benches, hills, and mountains. Slopes are 2 to 35 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Lithic Xeric Haplargids

TYPICAL PEDON: Loomis very gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 40 percent gravel and 20 percent cobbles.

A--0 to 5 cm; light brownish gray (10YR 6/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; strong thick platy structure; soft, very friable, moderately sticky and slightly plastic; few very fine roots; many very fine vesicular pores; 30 percent gravel and 20 percent cobbles; neutral (pH 7.0); abrupt smooth boundary. (2 to 8 cm thick)

Bt1--5 to 10 cm; pale brown (10YR 6/3) cobbly clay loam, dark brown (10YR 3/3) moist; weak very fine subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; common very fine and few fine roots; common very fine tubular pores; few faint clay films on faces of peds and lining pores; 10 percent gravel and 15 percent cobbles; neutral (pH 7.0); clear wavy boundary. (5 to 10 cm thick)

Bt2--10 to 18 cm; pale brown (10YR 6/3) extremely cobbly clay loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine tubular pores; common faint clay films on faces of peds and lining pores; 35 percent gravel and 25 percent cobbles; neutral (pH 7.2); clear wavy boundary. (8 to 18 cm thick)

Bt3--18 to 28 cm; pale brown (10YR 6/3) very cobbly clay, brown (10YR 4/3) moist; strong fine and medium subangular blocky structure; hard, very friable, very sticky and very plastic; few very fine roots; few very fine tubular pores; common distinct clay films on faces of peds and lining pores; 25 percent gravel and 30 percent cobbles; slightly alkaline (pH 7.4); abrupt irregular boundary. (0 to 18 cm thick)

R--28 cm; fractured rhyolite bedrock; distinct clay films on fracture surfaces in the upper 5 cm; few very fine roots along fractures.

TYPE LOCATION: Elko County, Nevada; about 36 miles north of Elko; about 1,500 feet north and 200 feet west of the southeast corner of section 14, T. 39 N., R. 57 E.; USGS Double Mountain SE 7.5 minute topographic quadrangle; latitude 41 degrees 16 minutes 03 seconds N and longitude 115 degrees 30 minutes 32 seconds W; WGS84 Decimal Degrees 41.2675000 latitude, -115.5088889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry; moist in winter and spring, dry from June through October; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Ochric epipedon thickness: 2 to 8 cm.
Depth to bedrock: 20 to 36 cm to a lithic contact.
Reaction: Neutral or slightly alkaline.

Particle-size control section - Clay content: Averages 35 to 55 percent.
Rock fragments: 35 to 75 percent, up to 40 percent of which may be cobbles. Lithology of fragments are typically volcanic rocks such as rhyolite.

A horizon
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 2 through 4, dry or moist.

Bt horizons
Value: 5 through 6 dry, 3 through 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Very gravelly clay loam, very cobbly clay loam, very gravelly clay, very cobbly clay, or extremely cobbly clay.
Clay content: 27 to 40 percent in the upper part and 40 to 60 percent in the lower part.
Rock fragments: 35 to 75 percent with up to 40 percent cobbles.
Structure: Moderate subangular blocky, angular blocky, or weak to strong prismatic.
Consistence: Soft to very hard dry, very friable to firm moist, and moderately sticky or very sticky and moderately plastic or very plastic wet.
Other features: Some pedons have few fine gypsum filaments or silica platelets in the lower subhorizon; some pedons have up to 15 percent stones on the surface.

COMPETING SERIES: These are the Burrita, Disage, Grumblen, Jung, Pipespring, and Rocconda series.

Burrita soils are moderately alkaline or strongly alkaline and have lithic contacts between 36 to 50 cm from the soil surface. Disage soils have lithic contacts between 36 and 50 cm from the soil surface. Grumblen soils have mean annual soil temperature of 11 to 13 degrees C. and have identifiable secondary carbonates in the lower part of the argillic horizon. Jung soils have moderately alkaline or strongly alkaline argillic horizons and have identifiable secondary carbonates in the lower part of the argillic horizon. Pipespring soils have mean annual soil temperature of 11 to 12 degrees C. Rocconda soils are calcareous in the argillic horizons and are dominated by channers.

GEOGRAPHIC SETTING: Loomis soils are on rock pediments, plateaus, structural benches, hills, and mountains. They typically occur on summit or shoulder positions. These soils formed in colluvium and residuum derived from volcanic and sedimentary rocks. Slopes are 2 to 35 percent. Elevations range from 1,375 to 2,045 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 330 mm, the mean annual temperature is 7 to 9 degrees C., and the frost-free period is 80 to 115 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Chiara soil. Chiara soils are loamy, shallow to duripans, and do not have argillic horizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very high surface runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Loomis soils are used for rangeland and wildlife habitat. The present vegetation is mainly black sagebrush, Douglas rabbitbrush, phlox, bluebunch wheatgrass, bottlebrush squirreltail, Nevada bluegrass, Thurber's needlegrass, Webber ricegrass, Sandberg's bluegrass, and cheatgrass.

DISTRIBUTION AND EXTENT: Northeastern Nevada, southwestern Idaho, and northeastern California. These soils are moderately extensive. The series concept and main acreage is in MLRA 25, while other acreage occurs in MLRA 23.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Elko County (Central Part), Nevada, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 5 cm (A horizon).
Argillic horizon - The zone from 5 to 28 cm (Bt1, Bt2, and Bt3 horizons).
Lithic contact - The boundary at 28 cm to underlying hard bedrock (R layer).
Particle-size control section - The zone from the soil surface to 28 cm (A, Bt1, Bt2, and Bt3 horizons).

ADDITIONAL DATA: Previous authors and editors include: PWD-GHL-RLB.

National Cooperative Soil Survey
U.S.A.