LOCATION TONOR OREstablished Series
TAXONOMIC CLASS: Ashy, glassy, frigid Sodic Xeric Haplocambids
TYPICAL PEDON: Tonor ashy silt loam--on a nearly level lakebed dominated by basin big sagebrush and black greasewood at an elevation of about 4,310 feet--rangeland. (Colors are for dry soil unless otherwise noted. When described on October 12, 1994, the soil was dry throughout.)
A--0 to 3 inches; light brownish gray (10YR 6/2) ashy silt loam, dark brown (10YR 3/3) moist; weak thin platy structure; slightly hard, very friable, slightly sticky and nonplastic; few very fine and fine roots; many fine vesicular pores; moderately alkaline (pH 8.0); clear smooth boundary. (3 to 9 inches thick)
Bw--3 to 11 inches; pale brown (10YR 6/3) ashy loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few very fine, few fine, and few medium roots; many very fine interstitial pores; slightly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (7 to 10 inches thick)
Bkn1--11 to 23 inches; pale brown (10YR 6/3) ashy loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few fine and few medium roots; many very fine interstitial pores; secondary carbonates finely disseminated in the matrix; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary.
Bkn2--23 to 43 inches; light gray (10YR 7/2) ashy sandy loam, brown (10YR 4/3) moist; weak coarse subangular blocky structure; hard, firm, nonsticky and nonplastic; few very fine roots; many fine interstitial pores; secondary carbonates finely disseminated in the matrix; violently effervescent; very strongly alkaline (pH 9.6); abrupt smooth boundary. (Combined thickness of the Bkn horizons ranges from 15 to 35 inches.)
2C--43 to 60 inches; very pale brown (10YR 8/2) very paragravelly ashy silt loam, light gray (10YR 7/2) moist; very fine and fine angular blocky rock structure; few very fine roots along fractures; many very fine interstitial pores; about 50 percent weakly cemented parapebbles; strongly effervescent; fine-earth is assumed to be high in diatoms and very high in volcanic glass; moderately alkaline (pH 8.2).
TYPE LOCATION: Lake County, Oregon; in the southeastern part of Fort Rock Valley; approximately 2,775 east and 330 feet north of the southwest corner of section 28, T. 27 S., R. 16 E.; USGS Thorn Lake 7.5 minute topographic quadrangle; 43 degrees 11 minutes 36 seconds north latitude and 120 degrees 49 minutes 40 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - These soils are moist in winter and spring; They are warmer than 41 degrees F. from about April 15 to November 1 and are dry within this period after July 1; Aridic moisture regime that borders on xeric.
Mean annual soil temperature - 44 to 47 degrees F.
Depth to base of cambic horizon - 10 to 15 inches.
Depth to identifiable secondary carbonates - 10 to 15 inches.
Depth to bedrock - More than 60 inches.
Depth to horizons with weakly cemented pararock fragments - 40 to 60 inches.
Particle-size control section - Clay content: Averages 15 to 25 percent.
A horizon
Value: 5 or 6 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Ashy silt loam or ashy sandy loam.
Volcanic glass content: 30 to 60 percent in coarse silt through fine sand fractions.
Bw horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Ashy loam or ashy silt loam.
Volcanic glass content: 30 to 60 percent in coarse silt through fine sand fractions.
Reaction: Moderately alkaline or strongly alkaline.
Salinity (EC): 0 to 4 mmhos/cm.
Sodicity (SAR): 4 to 13.
Effervescence: Slightly effervescent to violently effervescent.
Bkn horizons
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Ashy sandy loam, ashy loam, or ashy silt loam.
Clay content: 15 to 25 percent.
Volcanic glass content: 30 to 60 percent in coarse silt through fine sand fractions.
Reaction: Strongly alkaline or very strongly alkaline (up to pH 10.0).
Salinity (EC): 2 to 8 mmhos/cm.
Sodicity (SAR): 13 to 30.
Effervescence: Strongly effervescent or violently effervescent.
Calcium carbonate equivalent: 5 to 15 percent.
2C horizon
Pararock fragments: 35 to 60 percent parapebbles or parachanners.
Effervescence: Slightly effervescent to violently effervescent.
Volcanic glass content: 40 to 80 percent in coarse silt through fine sand fractions.
Other features: Pararock fragments consist of weakly cemented silty lacustrine deposits that are fractured. The majority of these fragments are water-stable and will not slake after air-drying and soaking in water for at least one hour. They are assumed to be high in diatom grains and volcanic glass.
COMPETING SERIES: These are the Abert and Thornlake series.
Abert soils have surface horizons with over 30 percent visible sand-size pumice grains, do not have horizons dominated by diatom grains, and do not have horizons between 40 and 60 inches with more than 35 percent pararock fragments. Thornlake soils do not have horizons dominated by diatom grains.
GEOGRAPHIC SETTING: Tonor soils are on lakebeds. These soils formed in lacustrine deposits derived from volcanic ash. The source of the volcanic ash is ancestral Mt. Mazama. Slopes are 0 to 15 percent. Elevations range from 4,300 to 4,400 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 8 to 10 inches, the mean annual temperature is 42 to 45 degrees F., and the frost-free period is 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Horning, Salhouse, and Youtlkue soils. Horning and Salhouse soils have ashy sandy textures in the particle-size control section and are on adjacent stable dunes. Youtlkue soils are moderately deep to paralithic contacts and on adjacent depressions on lakebeds.
DRAINAGE AND PERMEABILITY: Well drained; low surface runoff; moderately slow permeability (moderately high saturated hydraulic conductivity) in the lower substratum.
USE AND VEGETATION: Tonor soils are used for livestock grazing, irrigated cropland, and wildlife habitat. Alfalfa hay is the main crop. Potential native vegetation is black greasewood, basin big sagebrush, green rabbitbrush, gray rabbitbrush, and inland saltgrass.
DISTRIBUTION AND EXTENT: South-central Oregon. These soils are moderately extensive. MLRA 23.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Lake County (Northern Part), Oregon, 2006. The series was first proposed in Lake County, Oregon in 1961.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 7 inches (A horizon and part of the Bw horizon).
Cambic horizon - The zone from 3 to 11 inches (Bw horizon).
Identifiable secondary carbonates and sodic subgroup feature - The zone from 11 to 43 inches (Bkn1 and Bkn2 horizons).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 10 to 40 inches (Bkn1 horizon and parts of the Bw and Bkn2 horizons).
The revision of July 2001 updated the taxonomic class from Fine-loamy, mixed, frigid Sodic Xeric Haplocambids.
ADDITIONAL DATA: The typical pedon at the series type location is reference sampled for the Soil Survey Laboratory (SSL), Lincoln, NE, as soil survey sample number S94OR-037-004 (pedon # 95P0060). Selected data are available for the 2nd, 3rd, and 4th horizons.