LOCATION METTAH CA
Established Series
Rev: JPS/ET
10/2016
METTAH SERIES
The Mettah series consists of very deep, well drained soils formed in colluvium and residuum from weakly consolidated fluvial, beach, dune and estuarine deposits derived from mixed sources and subsequently uplifted. Mettah soils are on mountains and have slopes of 9 to 30 percent. The mean annual precipitation is about 2030 millimeters (80 inches) and the mean annual temperature is about 11 degrees C (52 degrees F).
TAXONOMIC CLASS: Fine, parasesquic, isomesic Andic Palehumults
TYPICAL PEDON: Mettah gravelly clay loam - on a west-facing slightly convex slope of 10 percent under redwood, Douglas-fir, tanoak, western hemlock, California huckleberry, Pacific rhododendron, and salal at 535 meters (1750 feet) elevation. (Colors are for moist soil unless otherwise stated. When described April 22, 2003, the soil was moist throughout.)
Oi--0 to 2 centimeter (0 to 1 inch); fresh and slightly decomposed conifer needles, tanoak leaves, and twigs; very strongly acid (pH 4.5); abrupt smooth boundary. (0 to 6 centimeters thick)
A--2 to 22 centimeters (1 to 9 inches); dark brown (7.5YR 3/3) gravelly clay loam, light brown (7.5YR 6/3) dry; weak fine subangular blocky and weak medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, common fine and medium roots; common very fine and fine irregular and many very fine and fine tubular pores; 15 percent well rounded gravel; moderately acid (pH 5.6); clear smooth boundary. (10 to 20 centimeters thick)
BAt--22 to 42 centimeters (9 to 17 inches); brown (7.5YR 4/4) silty clay loam, light brown (7.5YR 6/3) dry, weak fine subangular blocky and moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, and few medium roots; common very fine and fine irregular and common very fine and fine tubular pores; 10 percent well rounded gravel; moderately acid (pH 5.8); clear smooth boundary. (0 to 20 centimeters thick)
Bt1--42 to 69 centimeters (17 to 27 inches); reddish brown (5YR 4/4) silty clay, strong brown (7.5YR 4/6) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots, and few medium roots; common very fine and fine tubular pores; few faint and distinct clay films on faces of peds; 5 percent well rounded gravel; strongly acid (pH 5.4); clear smooth boundary.
Bt2--69 to 93 centimeters (27 to 37 inches); yellowish red (5YR 4/6) clay, reddish yellow (7.5YR 6/6) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine, and few medium and coarse roots; common very fine and fine tubular pores; common distinct clay films in pores and on faces of peds; 3 percent well rounded gravel; strongly acid (pH 5.4); clear smooth boundary.
Bt3--93 to 123 centimeters (37 to 48 inches); red (2.5YR 4/8) clay, reddish yellow (5YR 6/8) dry; moderate fine and medium subangular blocky structure; moderately hard, firm, moderately sticky and very plastic; few very fine, and common fine and medium roots; common very fine and fine tubular pores; many distinct clay films in pores and on faces of peds; 1 percent well rounded gravel; strongly acid (pH 5.2); clear wavy boundary. (Combined thickness of upper Bt horizons is 60 to 125 centimeters)
Bt4--123 to 131 centimeters (48 to 52 inches); red (2.5YR 4/8) clay, red (2.5YR 5/8) dry; moderate fine and medium subangular blocky structure; moderately hard, firm, moderately sticky and very plastic; few very fine and fine, and common medium roots; common very fine and fine tubular pores; many distinct clay films in pores and on faces of peds; 1 percent well rounded gravel; strongly acid (pH 5.2); clear wavy boundary.
Bt5--131 to 148 centimeters (52 to 58 inches); red (2.5YR 5/8) clay, reddish yellow (5YR 6/8) dry; moderate fine and medium subangular blocky structure; moderately hard, firm, moderately sticky and very plastic; few fine and medium roots; few very fine and fine tubular pores; many distinct clay films in pores and on faces of peds; 3 percent well rounded gravel; strongly acid (pH 5.2); gradual wavy boundary.
Bt6--148 to 200 centimeters (58 to 79 inches); red (2.5YR 5/8) clay loam, reddish yellow (5YR 6/8) dry; weak medium and coarse subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; few fine roots; few very fine and fine irregular pores; many distinct clay films in pores and on faces of peds; 3 percent well rounded gravel; very strongly acid (pH 5.0). (Combined thickness of lower Bt horizons is 50 to 105 centimeters)
TYPE LOCATION: Redwood National Park, Humboldt County, California; Holter Ridge, located 8.25 kilometers north on Lost Man Creek Trail from Ball Hills Road trailhead; southwest quarter, northeast quarter, Section 21, T. 11N. R. 2E. 41 degree, 19 minutes, 39.20 seconds north latitude (41.3275556 N) and 123 degrees, 57 minutes, 0.2 seconds west longitude (-123.9500556 W); HBLM; USGS Holter Ridge Quadrangle. UTM Zone 10 420495mE 4575555mN; NAD83
RANGE IN CHARACTERISTICS:
Soil Moisture: The soils are usually moist in all parts in the soil moisture control section in most years, but become nearly dry in the upper part from about September 15 to October 15 in most years. The soils have an Udic moisture regime.
Soil Temperature: The mean annual soil temperature is 10 to 13 degrees C (50 to 55 degrees F). The difference between mean summer and mean winter temperature is 3 to 5 degrees C.
Organic Matter: There is 12 to 20 kg per square meter of organic carbon to a depth of one meter.
CEC to clay ratio is 16 to 30 meq/100g in the major part of the argillic horizon.
Reaction is moderately or strongly acid throughout. Base saturation is 3 to 25 percent between depths of 25 to 200 centimeters.
Particle-Size Control Section (weighted average):
Rock fragments: 0 to 15 percent gravel.
Clay content: 40 to 60 percent clay.
O horizon
Hue: 10YR.
Value: 2 through 6 dry and moist.
Chroma: 1 through 4 dry and moist.
Texture: slightly decomposed organic material.
Wood fragments: 0 to 35 percent.
Reaction: moderately to very strongly acid.
A horizon
Hue: 5YR, 7.5YR, or 10YR.
Value: 4 through 6 dry, 3 or 4 moist.
Chroma: 3 through 6 dry and moist.
Texture of fine earth: clay loam.
Rock fragments: 0 to 15 percent gravel.
Clay content: 27 to 35 percent.
Bt horizon (upper)
Hue: 2.5YR, 5YR, or 7.5YR.
Value: 5 or 6 dry, 3 through 6 moist.
Chroma: 4 through 8 dry, 4 through 8 moist.
Texture of fine earth: silty clay or clay.
Rock fragments: 0 to 15 percent gravel.
Clay content: 40 to 60 percent.
Bt horizon (lower)
Hue: 2.5YR, 5YR, or 7.5YR.
Value: 5 or 6 dry, 3 through 6 moist.
Chroma: 4 through 8 dry and moist.
Texture of fine earth: clay loam, silty clay loam, or clay.
Rock fragments: 0 to 30 percent gravel and 0 to 5 percent cobbles.
Clay content: 32 to 45 percent.
COMPETING SERIES: This is the
Notchko series. Notchko soils have an ustic soil moisture regime.
GEOGRAPHIC SETTING: Mettah soils occur on moderately broad ridges and upper slopes of mountains. Slopes are 9 to 30 percent. Elevations are 296 to 690 meters (970 to 2260 feet). The soils formed in colluvium and residuum from weakly consolidated fluvial, beach, dune and estuarine deposits derived from mixed sources which have been uplifted. The climate is humid with cool foggy summers and cool moist winters. Coastal influence limits the annual and diurnal range in temperature. Mean annual precipitation ranges from 1780 to 2290 millimeters (70 to 90 inches). Mean January temperature is about 9 degrees C; mean July temperature is about 14 degrees C; and the mean annual temperature is 10 to 13 degrees C (50 to 55 degrees F). Frost-free season is 240 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Surpur and the
Ossagon soils. Surpur soils are fine-loamy. Ossagon soils have an umbric epipedon and are yellower than 7.5YR throughout. The Surpur soils are found on weakly consolidated sandy beach and dune deposits. The Ossagon soils are found at lower elevations and closer to the coast.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very high runoff; moderately low to low saturated hydraulic conductivity.
USE AND VEGETATION: This soil has been used for commercial timber and is used for recreation, wildlife and watershed. Natural vegetation consists of redwood, Douglas-fir, western hemlock, tanoak, huckleberry, and rhododendron.
DISTRIBUTION AND EXTENT: California Coastal Redwood Belt; MLRA 4B. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt Del Norte Area, California 2007. Source of name is from Mettah Creek east of the town of Orick.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon - the zone from 0 to 22 centimeters.
2. Argillic horizon - the zone from 22 to 200 centimeters.
3. Ultisol feature - base saturation of 7 percent at the critical depth, 125 centimeters below the upper boundary of the argillic horizon
4. Humult feature - 13.4 kilograms per square meter of organic carbon to a depth of 1 meter
5. Parasesquic mineralogy - There is 11 percent dithionite-extractable sesquioxides in the clay fraction of the particle-size control section
6. Palehumult features - Clay remains at least 80 percent of its maximum to a depth of 200 centimeters, 45 to 38 percent clay.
7. CEC to clay ratio is 16 to 30 cmol/kg of clay in the major part of the argillic horizon
8. Particle-size control section - the zone from 22 to 72 centimeters, (Bt1 and Bt2 horizons) averages 41 percent clay, and 6 percent rock fragments.
9. Andic subgroup properties - The zone from 2 to 22 centimeters
(greater than 18 centimeters thick )has a bulk density of .80, and Al plus Fe percentages (by ammonium oxalate) totaling 1.06. (A horizon)
ADDITIONAL DATA: NSSL, Lincoln Lab sample number 03N0671.
Soil classified using the 12th Edition of the Keys to Soil Taxonomy.
National Cooperative Soil Survey
U.S.A.