LOCATION TRONSEN WAEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, mesic Vitrandic Palexerolls
TYPICAL PEDON: Tronsen stony ashy silt loam - rangeland on a 60 percent south-facing slope at an elevation of 3,800 feet. The soil was moist when described. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
A--0 to 9 inches; dark grayish brown (10YR 4/2) stony ashy silt loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; common fine and medium tubular pores; 15 percent gravel, 5 percent cobbles and 5 percent stones, with 1 percent surface stones; neutral (pH 6.8); clear smooth boundary. (7 to 11 inches thick)
BAt--9 to 16 inches; brown (10YR 4/3) very gravelly clay loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common fine and medium roots; common fine and medium tubular pores; common faint clay films of ped surfaces; 30 percent gravel and 10 percent cobbles; neutral (pH 6.8); clear wavy boundary. (5 to 9 inches thick)
Bt1--16 to 30 inches; yellowish brown (10YR 5/4) very gravelly clay loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; very hard, very firm, moderately sticky and moderately plastic; common fine and medium roots; common fine tubular pores; common faint clay films on faces of peds; 30 percent gravel and 10 percent cobbles; neutral (pH 6.6); clear wavy boundary. (12 to 19 inches)
Bt2--30 to 60 inches; pale brown (10YR 6/3) extremely gravelly clay, brown (10YR 4/3) moist; moderate coarse subangular blocky structure; massive; extremely hard, extremely firm, very sticky and very plastic; few fine roots; common fine and medium tubular pores; few faint clay films on faces of peds; 50 percent gravel and 15 percent cobbles; neutral (pH 6.6).
TYPE LOCATION: Chelan County, Washington; about 5 miles northwest of Sunnyslope; 400 feet east of Eagle Rock; near center section 30, T. 24 N., R. 20 E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 52 degrees F. These soils are usually moist but are dry in the moisture control section for 90 to 105 consecutive days following summer solstice. The particle-size control section averages 35 to 80 percent rock fragments and averages 35 to 50 percent clay. The upper 7 to 11 inches has an estimated moist bulk density of 1.20 to 1.50, volcanic glass content of 5 to 20 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.15 to 0.35 percent and 15-bar water retention of 5 to 10 percent air dried samples. The mollic epipedon is 10 to 20 inches thick.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 1 to 3 dry and moist. Texture is stony ashy silt loam or stony ashy loam.
The BAt horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry and chroma of 2 or 3 dry and moist. Texture is very gravelly clay loam, very gravelly clay, or very cobbly clay loam.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 to 6 dry, 3 to 5 moist and chroma of 3 or 4 dry and moist. Texture is very gravelly clay, very gravelly clay loam, very cobbly clay loam, extremely gravelly clay, extremely gravelly clay loam or very cobbly clay. Reaction is neutral or slightly alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Tronsen soils are on benches, ridgetops, hillslopes, canyon side slopes and mountain side slopes at elevations of 800 to 4,200 feet. Slopes are 2 to 65 percent. These soils formed in residuum and colluvium derived from basalt or andesite mixed with loess and volcanic ash in the upper part. They are in a climate with warm, dry summers and cool, moist winters. The mean annual precipitation is 12 to 16 inches. The average January temperature is about 25 degrees F. and the average July temperature is about 70 degrees F. The mean annual temperature is 46 to 50 degrees F. The frost-free season is 120 to 165 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Benwy, Cheviot, and Yaxon soils. Benwy soils on old alluvial fans and Yaxon soils on hill slopes are fine-loamy. Cheviot soils are on hillslopes and are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well-drained; slow to rapid runoff; slow permeability.
USE AND VEGETATION: These soils are used for livestock grazing, wildlife habitat, watershed and recreation. Native vegetation is bluebunch wheatgrass, Sandberg bluegrass, Wyoming big sagebrush, and antelope bitterbrush.
DISTRIBUTION AND EXTENT: Central Washington. MLRA 8. This series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Chelan County, Washington, 1969.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon the zone from 0 to 16 inches
Argillic horizon the zone from 9 to 60 inches that has an increase in clay of more than 15 percent, absolute, within 1 inch and the clay does not decrease by as much as 20 percent within 60 inches
Vitrandic feature the zone from 0 to 9 inches
Particle-size control section the zone from 9 to 29 inches