LOCATION MEDICI CAEstablished Series
TAXONOMIC CLASS: Medial over loamy-skeletal, mixed, superactive, frigid Typic Haploxerands
TYPICAL PEDON: Medici coarse sandy loam on a northeast facing 12 percent slope under a cover of mixed conifers at an elevation of 4,760 feet. (Colors are for dry soil unless otherwise stated. When described May 17, 1984, the soil was slightly moist throughout.)
Oi--2 to 0 inches; decomposing litter.
A1--0 to 1 inches; grayish brown (10YR 5/2) coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; few very fine interstitial pores; 10 percent gravel; NaF pH 10.0; moderately acid (pH 6.0); abrupt smooth boundary. (1 to 5 inches thick)
A2--1 to 8 inches; light gray (10YR 7/2) gravelly coarse sandy loam, brown (7.5YR 4/2) moist; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common medium and many fine roots; few very fine interstitial pores; 20 percent gravel; NaF pH 10.5; moderately acid (pH 6.0); abrupt smooth boundary. (6 to 9 inches thick)
Bw1--8 to 19 inches; pink (7.5YR 7/4) gravelly coarse sandy loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; soft, loose, nonsticky and nonplastic; few coarse, fine, medium and many fine roots; common very fine interstitial pores; 20 percent gravel; NaF pH 10.5; slightly acid (pH 6.4); clear smooth boundary. (8 to 13 inches thick)
2Bw2--19 to 31 inches; pink (7.5YR 7/4) very gravelly coarse sandy loam, strong brown (7.5YR 4/6) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common medium and fine roots; common very fine interstitial pores; 50 percent gravel; NaF pH 10.0; neutral (pH 6.6); gradual smooth boundary.
2Bw3--31 to 51 inches; pink (7.5YR 7/4) very gravelly coarse sandy loam, strong brown (7.5YR 4/6) moist; moderate medium subangular blocky structure; soft, friable, nonsticky and nonplastic; common medium and fine roots; common very fine interstitial and few very fine tubular pores; 50 percent gravel; NaF pH 9.8; neutral (pH 6.6); gradual smooth boundary. (Combined thickness of the 2Bw3 and 2Bw4 horizons is 28 to 35 inches)
2Bw4--51 to 67 inches; pink (7.5YR 7/4) very gravelly loam, strong brown (7.5YR 4/6) moist; moderate medium subangular blocky structure; soft, friable, nonsticky and nonplastic; few medium roots; common very fine interstitial and few very fine tubular pores; 50 percent gravel; NaF pH 9.8; neutral (pH 6.6); clear wavy boundary. (14 to 18 inches thick)
3C--67 to 75 inches; very pale brown (10YR 7/3) stratified coarse sand, brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic; few fine roots; few very fine interstitial pores; 10 percent gravel; NaF pH 9.6; neutral (pH 6.6).
TYPE LOCATION: Modoc County, California; about 2.3 miles northwest of Longbell Fire Station; 2,700 feet west and 3,800 feet north of the southeast corner of sec. 7, T. 42 N., R. 5 E., Whitehorse NW (Border Mtn.) quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Depth to base of the cambic horizon is greater than 60 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 (13 to 45 inches) is dry in all parts from early July to about mid September ranges from 75 to 90 days and is moist in all parts from early November to early June. The bulk density estimated to range from 0.70 to 0.90.
The A1 horizon color is 10YR 4/2, 5/2 or 5/3. Moist color is 10YR 2/1, 3/1, 3/2, 3/3, or 4/2. Clay content ranges from 12 to 15 percent. Rock fragments, mostly andesitic gravel, range from 5 to 10 percent. Reaction is slightly acid or moderately acid. Glass content is estimated to range from 30 to 40 percent of the 0.2 to 2mm fraction. Organic matter ranges from 2 to 8 percent.
The A2 horizon color is 7.5YR and 10YR 6/4, 7/2, or 7/4. Moist color is 10YR 4/2 or 4/4. Clay content ranges from 12 to 15 percent. Rock fragments, mostly andesitic gravel, range from 15 to 35 percent. Reaction is slightly acid or moderately acid. Glass content is estimated to range from 15 to 30 percent of the 0.2 to 2 mm fraction. Organic matter ranges from 1 to 2 percent.
The Bw horizon color is 7.5YR 5/4, 6/4, or 7/4. Moist color is 7.5YR 3/4, 4/4, or 4/6. Clay content ranges from 12 to 18 percent. Rock fragments, mostly andesitic gravel, range from 20 to 35 percent. Reaction is neutral or slightly acid. Glass content is estimated to range from 15 to 30 percent of the 0.2 to 2 mm fraction. Organic matter ranges from 1 to 2 percent.
The 2Bw horizon color is 7.5YR 5/4, 6/4, or 7/4. Moist color is 7.5YR 3/4, 4/4, or 4/6. Organic matter ranges from lessthan 0.5 to 1.0 percent. Texture is very gravelly coarse sandy loam, very gravelly loam or extremely gravelly coarse sandy loam. Clay content ranges from 12 to 18 percent. Rock fragments, mostly andesitic gravel, range from 35 to 80 percent. Reaction is neutral or slightly acid. Glass content is estimated to range from 15 to 30 percent of the 0.2 to 2 mm fraction.
The 3C horizon color is 10YR 6/4, 7/3; 7.5YR 7/4 or 7/6. Moist color is 10YR 4/3, 4/4, 6/4, or 7.5YR 4/6. Texture is stratified coarse sand, sand, or loamy coarse sand. Clay content ranges from 5 to 12 percent. Rock fragments, mostly cinder gravel, range from 10 to 80 percent. Reaction is neutral or slightly acid. Organic matter ranges from 0 to less than 0.5 percent.
Andic property data (see remarks for explanation):
Depth P-ret B.D. pH NaF Glass Alo Feo 15 barH20
0-1 75 1.00 10.0 39 1.01 0.65 16.1
1-8 68 1.08 10.0 37 0.91 0.69 15.2
8-19 68 1.05 4.8 20 0.90 0.71 17.6
19-31 64 1.13 9.8 3 0.79 0.88 21.5
31-51 58 ND 9.5 6 0.76 0.98 22.2
51-67 56 ND 9.5 ND 0.76 0.67 23.5
67-75 48 ND 9.5 ND 0.51 0.57 24.1
COMPETING SERIES: These are the Carberry (T) and Stacher (T) series. These soils lack glass and are dominated by allophane.
GEOGRAPHIC SETTING: Medici soils are on hills. Slopes are 2 to 30 percent. These soils formed in tephra. Elevation is 4300 to 5400 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 72 inches. The mean annual temperature is 42 to 45 degrees F. The mean January temperature is about 27 degrees F. The mean July temperature is about 55 degrees F. Frost-free season is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blankout, Longbell and Medlake soils. Blankout soils are on hills, are very deep and are medial over loamy. Longbell soils are on plateaus, are very deep, have umbric epipedon and are mesic. Medlake soils are on hills, are very deep, have 20 to 32 inches of pumice over a buried cambic horizon, are pumiceous over medial and are frigid.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: This soil is used for timber production. The natural vegetation is white fir, ponderosa pine, sugar pine, incense cedar, greenleaf manzanita, squawcarpet, snowbrush ceonothus, antelope bitterbrush and sierra chinkapin.
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 coined.
REMARKS: Rock fragments, mostly gravel on the soil surface, range from 10 to 15 percent. Laboratory analysis of adjoining soils in addition to supporting field study place this soil in the order Andisols.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 8 inches (A1, A2).
Cambic horizon - 8 to 67 inches (Bw1, 2Bw2, 2Bw3, 2Bw4).
Particle size control section is from 0 to 40 inches.
Andic properties are assumed in the upper 14 inches.
Additional data: Lab data from UC Davis Laboratory, from nearby profile, Lab# 1623 and 1620, type location for the Blankout series.