LOCATION EAGLELAKE CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, isotic, frigid Vitrandic Haploxeralfs
TYPICAL PEDON: Eaglelake very gravelly ashy loam--on a 3 percent slope under mixed conifers and shrubs at 6,200 feet elevation--forestland. (Colors are for dry soil unless otherwise noted. When described August 23, 1985, the soil was dry throughout.) The soil surface is covered with about one inch of undecomposed and slightly decomposed needles, twigs, and sticks.
A1--0 to 3 inches; reddish brown (5YR 5/3) very gravelly ashy loam, dark reddish brown (5YR 3/3) moist; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; many very fine interstitial pores; 45 percent gravel; sodium fluoride pH is 10.6; slightly acid (pH 6.5); clear wavy boundary.
A2--3 to 7 inches; reddish brown (5YR 5/3) very gravelly ashy loam, dark reddish brown (5YR 3/4) moist; weak very fine and fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; many very fine interstitial pores; 35 percent gravel; sodium fluoride pH is 9.8; slightly acid (pH 6.3); clear wavy boundary. (Combined thickness of the A horizons is 2 to 12 inches thick.)
BAt--7 to 11 inches; reddish brown (5YR 5/4) ashy loam, dark reddish brown (2.5YR 3/4) moist; moderate very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and common fine and medium roots; many very fine tubular and interstitial pores; few faint clay films as bridges between mineral grains; 10 percent gravel; sodium fluoride pH is 9.4; moderately acid (pH 6.0); clear wavy boundary. (4 to 9 inches thick)
Bt--11 to 16 inches; reddish brown (2.5YR 5/4) loam, reddish brown (2.5YR 4/4) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine common fine and few medium roots; common faint clay films on faces of peds and lining pores; 10 percent gravel; sodium fluoride pH is 8.6; moderately acid (pH 6.0); clear wavy boundary. (4 to 7 inches thick)
2Bt1--16 to 25 inches; reddish brown (2.5YR 5/4) gravelly clay loam, reddish brown (2.5YR 4/4) moist; strong medium and coarse subangular blocky structure; very hard, very friable, moderately sticky and moderately plastic; common very fine, common fine, and few medium roots; many very fine tubular pores; common faint and distinct clay films on faces of peds and lining pores; 5 percent cobbles and 25 percent gravel; sodium fluoride pH is 8.6; moderately acid (pH 5.8); clear wavy boundary.
2Bt2--25 to 54 inches; reddish brown (2.5YR 5/4) gravelly clay loam, dark red (2.5YR 3/6) moist; moderate coarse subangular blocky structure; very hard, friable, sticky and plastic; common very fine roots; many very fine tubular and interstitial pores; common thin and moderately thick clay films on peds and in pores; 25 percent gravel; sodium fluoride pH is 8.6; moderately acid (pH 5.8); clear wavy boundary. (Combined thickness of the 2Bt horizons is 19 to 41 inches.)
3Crt--54 to 76 inches; pinkish gray (5YR 7/2) and yellowish red (5YR 5/8) soft weathered andesite, reddish brown (5YR 5/4) and yellowish red (5YR 4/6) moist; massive; crushes easily; retains rock structure; digs with spade or auger; very fine roots in some pockets; few in situ clay films.
TYPE LOCATION: Lassen County, California; about 16 miles north of Susanville; found by going north along U.S. Highway 44 to the intersection of McCoy Road and Bridge Creek Road, then east on Bridge Creek Road 1.6 miles to another main intersection, then south 1.2 miles to fork and continue 0.5 mile to Road 3.15; then northwest 2.5 miles on Road 3.15 to Road 3.10, then north to site and 150 feet south of next intersection; approximately 700 feet east and 2,600 feet north of the southwest corner of section 4, T. 30 N., R. 10 E.; USGS Roop Mountain 7.5 minute topographic quadrangle; 40 degrees 29 minutes 25 seconds north latitude and 120 degrees 52 minutes 03 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil moisture control section (10 to 22 inches) is dry in all parts from July 15 to November 1 (107 days) and is moist in some or all parts the rest of the time; The soil temperature exceeds 41 degrees F. from May 1 to December 1 (214 days) and exceeds 47 degrees F. from June 1 to November 1; Xeric moisture regime.
Mean annual soil temperature - 44 to 46 degrees F.
Depth to base of argillic horizon - 40 to 60 inches.
Depth to bedrock - 40 to 60 inches to a paralithic contact. The paralithic materials below the contact are soft, weathered andesite or basalt.
Particle-size control section - Clay content: Averages 27 to 35 percent; Rock fragments: Averages 15 to 30 percent, mainly gravel. Lithology of fragments are volcanic rocks such as basalt or andesite.
Base saturation by sum of cations - 50 to 75 percent.
A horizons - Dry color: 7.5YR 5/4; 5YR 5/3, 5/4 or 2.5YR 5/6.
Moist color: 5YR 3/3, 3/4 or 2.5YR 3/4.
Rock fragments: 35 to 45 percent, mainly gravel.
Volcanic glass content: 5 to 15 percent.
Oxalate extractable aluminum plus one half extractable iron: 0.5 to 1.0 percent.
Sodium fluoride pH: 9.5 to 10.8.
BAt horizon - Dry color: 5YR 5/4; 7.5YR 5/4 or 2.5YR 5/4.
Moist color: 5YR 3/4, 4/4; 2.5YR 3/4 or 4/4.
Clay content: 20 to 25 percent.
Rock fragments: 5 to 15 percent gravel.
Volcanic glass content: 5 to 15 percent.
Oxalate extractable aluminum plus one half extractable iron: 0.5 to 1.0 percent.
Sodium fluoride pH: 9.0 to 10.0.
Bt horizon - Dry color: 5YR 5/4; 7.5YR 5/4 or 2.5YR 5/4.
Moist color: 5YR 3/4, 4/4; 2.5YR 3/4 or 4/4.
Clay content: 20 to 25 percent.
Rock fragments: 5 to 15 percent gravel.
Sodium fluoride pH: 8.5 to 9.6.
2Bt horizons - Dry color: 5YR 5/4, 5/6 or 2.5YR 5/4.
Moist color: 5YR 3/4; 2.5YR 3/4, 4/4 or 3/6.
Clay content: 27 to 35 percent.
Rock fragments: 15 to 30 percent gravel.
Sodium fluoride pH: 8.2 to 9.6.
COMPETING SERIES: These are the Ketchly, Kruse, McEwen, Nahahum, Nard, Nardmont, Neuske, and Panak series.
Ketchly soils have umbric epipedons and are dry in the moisture control section for 60 to 80 consecutive days following the summer solstice. Kruse, McEwen, Nahahum, Nard, Nardmont, Neuske, and Panak soils are very deep.
GEOGRAPHIC SETTING: Eaglelake soils are on plateaus and mountains. These soils formed in volcanic ash over colluvium and residuum derived from basalt or andesite. Slopes are 2 to 50 percent. Elevations range from 5,200 to 6,500 feet. The climate is subhumid with cold, moist winters and warm, dry summers. The mean annual precipitation is 20 to 30 inches with 40 to 60 inches of snow. The mean annual temperature is 43 to 45 degrees F., the mean July temperature is about 60 degrees F., and the mean January temperature is about 28 degrees F. The frost-free period is 60 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Outland and Weste soils. Outland soils are loamy-skeletal and moderately deep to paralithic contacts. Weste soils are loamy-skeletal, moderately deep to lithic contacts, and have andic soil properties in the upper 7 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium or high surface runoff; moderately slow permeability.
USE AND VEGETATION: Eaglelake soils are used for timber production. The vegetation is mainly a forest canopy of Jeffrey pine, sugar pine, white fir, and incense-cedar with an understory of whitethorn, greenleaf manzanita, and squawcarpet.
DISTRIBUTION AND EXTENT: Northeastern California. These soils are moderately extensive. MLRA 22B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Lassen County (Susanville Area Soil Survey), California, 2000.
REMARKS: The revision of January 2004 updated the taxonomic class from Fine-loamy, mixed, superactive, frigid Ultic Haploxeralfs based on the field determined values for sodium fluoride pH and laboratory data on similar soils in the survey area.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 11 inches (A1, A2, and BAt horizons).
Vitrandic intergrade feature - The zone from the soil surface to 11 inches (A1, A2, and BAt horizons).
Argillic horizon - The zone from 11 to 54 inches (Bt, 2Bt1, and 2Bt2 horizons).
Paralithic contact - The boundary at 54 inches to underlying soft, weathered bedrock (3Crt layer).
Particle-size control section - The zone from 11 to 31 inches (Bt and 2Bt1 horizons and part of the 2Bt2 horizon).