LOCATION TIONESTA CAEstablished Series
TAXONOMIC CLASS: Pumiceous or ashy-pumiceous over medial-skeletal, mixed, frigid Typic Haploxerands
TYPICAL PEDON: Tionesta very gravelly loamy coarse sand on a northwest facing 5 percent slope under a cover of mixed conifers and brush at an elevation of 5100 feet. (Colors are for dry soil unless, otherwise stated. When described June 14, 1989,the soil was slightly moist throughout).
Oi--3 to 0 inches; recent and decomposed litter.
A--0 to 5 inches; gray (N 5/1) very gravelly loamy coarse sand, black (7.5YR 2/0) moist; single grain; loose, nonsticky and nonplastic; common very fine and few fine roots; many very fine interstitial pores; 45 percent pumice gravel; slightly acid (pH 6.2); abrupt smooth boundary. (4 to 7 inches thick)
C--5 to 15 inches; 60 percent white (10YR 8/2), and 40 percent strong brown (7.5YR 4/6) extremely gravelly coarse sand, 60 percent white (10YR 8/2), and 40 percent brown (7.5YR 4/4) moist; single grain; loose, nonsticky and nonplastic; common very fine, few fine, medium and coarse roots; many very fine interstitial pores; 80 percent pumice gravel; neutral (pH 6.7); abrupt smooth boundary. (5 to 12 inches thick)
2Bw1--15 to 31 inches; light brown (7.5YR 6/4) gravelly coarse sandy loam, brown (7.5YR 4/4) moist; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and medium, few very fine and coarse roots; many very fine interstitial pores; 30 percent andesite gravel; neutral (pH 6.7); clear wavy boundary. (13 to 18 inches thick)
2Bw2--31 to 53 inches; pink (7.5YR 7/4) extremely gravelly coarse sandy loam; brown (7.5YR 5/4) moist; single grain; loose, nonsticky and nonplastic; common fine and medium, few coarse roots; many very fine interstitial pores; 55 percent andesite gravel, 10 percent cobbles; neutral (pH 6.7); clear wavy boundary. (18 to 25 inches thick)
3Bw3--53 to 70 inches; reddish yellow (7.5YR 7/6) extremely gravelly loamy coarse sand; brown (7.5YR 5/4) moist; single grain; loose, nonsticky and nonplastic; few fine and medium roots; many very fine interstitial pores; 40 percent andesite gravel, 30 percent basalt cobbles; neutral (pH 6.7).
TYPE LOCATION: Modoc County, California; about 8.2 miles southwest of Tionesta, on road of Old Camp to Black Mtn.; 2680 feet south and 2,300 feet east of the northwest corner of sec. 18, T. 43 N., R. 5 E., Timber Mtn. SW (West of Kephart) quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Depth to bedrock is greater than 80 inches. The mean annual soil temperature is 40 to 47 degrees F. The soil temperature exceeds 41 degrees F.from mid May to mid November (185 days) and exceeds 47 degrees F. from early July to early October. The soil moisture control section (24 to 60 inches) is dry in all parts from early July to mid September ranges from (75 to 90 days) and is moist in all parts from early November to early June. The particle-size control section (0 to 40 inches) ranges from 2 to 18 percent clay and 15 to 90 percent rock fragments.
The A horizon color is 10YR 4/1, 5/1, 5/2, 6/1 or 6/2. Moist color is 10YR 2/1, 2/2, 3/1, 3/2, 4/2 or N 2/0. Organic matter ranges from 6 to 9 percent. Clay content ranges from 5 to 10 percent. Rock fragments, mostly rhyolitic pumice gravel range from 35 to 60 percent. NaF pH ranges from 8.0 to 8.8. Reaction is slightly acid or moderately acid.
The C horizon color is 10YR 7/2, 8/1 or 8/2 or 7.5YR 4/6. Moist color is 10YR 8/2, 8/3 or 8/4 or 7.5YR 4/4. Organic matter ranges from 2 to 4 percent. Clay content ranges from 2 to 5 percent. Rock fragments, mostly rhyolitic pumice gravel range from 60 to 90 percent. NaF pH ranges from 8.0 to 8.8. Reaction is slightly acid or neutral.
The 2Bw1 horizon color is 7.5YR 4/4, 5/4, or 6/4. Moist color is 7.5YR 3/4, or 4/4. Organic matter ranges from 1.0 to 2.0 percent. Clay content ranges from 12 to 15 percent. Rock fragments, mostly gravel range from 15 to 30 percent and cobbles range from 0 to 10 percent. NaF pH ranges from 10.0 to 11.5. Reaction is slightly acid or neutral.
The 2Bw2 and 3Bw3 horizon color is 7.5YR 6/4, 7/4, or 7/6. Moist color is 7.5YR 4/4, or 5/4. Organic matter ranges from 0.5 to 1.0 percent. Texture is extremely gravelly coarse sandy loam or extremely gravelly loamy coarse sand. Clay content ranges from 5 to 15 percent. Rock fragments, mostly gravel ranges from 50 to 60 percent and cobbles range from 10 to 30 percent. Stones range form 0 to 10 percent. NaF pH ranges from 10.0 to 10.5. Reaction is slightly acid or neutral.
Andic Properties Data: (see remarks for explanation)
Depth P-ret B.D. pH NaF Glass Alo Feo 15 barH20
0-5 31 0.92 8.8 73 0.72 0.28 11.6
5-15 15 NC 8.8 49 0.39 0.16 16.1
15-31 93 0.86 10.5 6 3.68 0.75 16.5
31-53 95 0.86 10.5 3 4.75 1.48 20.1
53-70 ND NC 10.5 9 3.20 2.74 26.6
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Tionesta soils are on hills. Slopes are 2 to 30 percent. These soils formed in tephra. Elevation is 5,000 to 5,800 feet. The climate is subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 25 to 35 inches. Snowfall is 48 to 60 inches. The mean annual temperature is 39 to 44 degrees F. The mean January temperature is about 27 degrees F. The mean July temperature is about 60 degrees F. Frost-free season is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blankout (T), Medlake (T) and Medici (T), soils. Blankout soils are on hills, are very deep, and are medial over loamy. Medlake soils are on hills, are deep and are pumiceous over medial. Medici soils are on hills, are very deep and are medial over loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; rapid permeability in the upper part and very rapid in the lower part of the B horizon.
USE AND VEGETATION: This soil is used for timber production. The natural vegetation is ponderosa pine, white fir, incense-cedar, sugar pine, jeffrey pine, greenleaf manzanita, snowbrush ceanothus, squirreltail, and antelope bitterbrush.
DISTRIBUTION AND EXTENT: Northeastern California. The soils are not extensive. MLRA is 22.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Modoc County, Intermountain Soil Survey Area, California 1994. Source of name is from the town of Tionesta.
REMARKS: Series reclassified on September, 1994. Competing series not reviewed at that time. Particle size class determined by the weighted averages of the contrasting particle size classes.
Diagnostic horizons and features recognized in this profile are:
Ochric epipedon- the zone from to soil surface to about 5 inches (A).
Cambic horizon- the zone from 15 to 53 inches (2Bw1, 2Bw2).
Rock fragments, mostly rhyolitic pumice gravel, on the soil surface, range from 40 to 80 percent.
Mineralogy is dominantly allophane/imogolite in the 2Bw1, 2Bw2, and 2Bw3 horizons.
ADDITIONAL DATA: This pedon was characterized by UC Davis in 1985. Sample number is # 1624 unpublished.