LOCATION CARLOTTA CATentative Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Oxyaquic Dystrudepts
TYPICAL PEDON: Carlotta loam - on a uniform, south facing slope of 1 percent under sweet vernal grass, ryegrass, velvet grass, tall fescue, plantain and creeping buttercup at 4 meters (13 feet elevation). (Colors are for moist soil unless otherwise stated. When described May 31, 2007, the soil was moist to 78 centimeters and wet, water table present, 78 to 152 centimeters).
Ap1--0 to 23 centimeters (0 to 9 inches); dark brown (10YR 3/3) loam, brown (10YR 5/3) dry; moderate very fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine and fine and common medium roots; common very fine and fine irregular pores and very fine and fine tubular pores; strongly acid (pH 5.2); clear smooth boundary.
Ap2--23 to 33 centimeters (9 to 13 inches); very dark grayish brown (10YR 3/2) loam, brown (10YR 4/3) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common very fine and fine roots; common very fine and fine tubular and very fine and fine irregular pores; 1 percent gravel; very strongly acid (pH 5.0); clear smooth boundary. (combined thickness of the Ap horizons is 30 to 80 centimeters)
BA--33 to 60 centimeters (13 to 24 inches); dark brown (10YR 3/3) clay loam, yellowish brown (10YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine and fine tubular and very fine and fine irregular pores; very few and discontinuous fine prominent yellowish red (5YR 5/6) masses of iron accumulation in the matrix; 1 percent gravel; very strongly acid (pH 5.0); clear wavy boundary. (0 to 30 centimeters thick)
Bw1--60 to 85 centimeters (24 to 34 inches); dark yellowish brown (10YR 4/4) clay loam, light yellowish brown (10YR 6/4) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; few very fine and fine roots; few very fine and fine irregular pores; common fine and medium prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; 1 percent gravel; strongly acid (pH 5.4); clear wavy boundary.
Bw2--85 to 110 centimeters (34 to 43 inches); olive brown (2.5Y 4/4) clay loam, pale yellow (2.5Y 7/4) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; few fine roots; common very fine and fine irregular and fine and medium tubular pores; common fine and medium prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix and fine and medium distinct grayish brown (2.5Y 5/2) iron depletions in the matrix; 1 percent gravel; moderately acid (pH 5.8); clear smooth boundary.
Bw3--110 to 130 centimeters (43 to 51 inches); yellowish brown (10YR 5/4) clay loam, very pale brown (10YR 7/4) dry; weak coarse subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common very fine and irregular pores; many fine and medium prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix and fine and medium distinct grayish brown (2.5Y 5/2) iron depletions in the matrix; 1 percent gravel; moderately acid (pH 5.8); clear smooth boundary. (combined thickness of the Bw horizons is 45 to 90 centimeters)
BC--130 to 152 centimeters (51 to 60 inches); yellowish brown (10YR 5/4) silty clay loam, very pale brown (10YR 7/4) dry; massive; moderately hard, firm firm, moderately sticky and moderately plastic; common very fine irregular pores; many fine and medium prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix and common fine and medium distinct grayish brown (2.5Y 5/2) iron depletions in the matrix; 1 percent gravel; moderately acid (pH 6.0). (0 to 25 centimeters thick)
TYPE LOCATION: Del Norte County, California; located approximately 50 meters south of Kellog Road; HBLM, USGS Crescent City Quadrangle; UTM Zone 10 401135mE 4635920mN; NAD83.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 12 to 15 degrees C (54 to 59 degrees F). The difference between the mean winter and mean summer soil temperatures varies from 6 to 9 degrees C. The soils are usually moist and are dry for less than 45 consecutive days in all parts between depths of 10 to 30 centimeters (4 and 12 inches) in the four months following the summer solstice.
Umbric epipedon is 30 to 100 centimeters (12 to 39 inches) thick.
Depth to Redoximorphic features: 50 to 100 centimeters (20 to 40 inches)
The particle-size control section (weighted average)
Rock fragments: 0 to 7 percent
Clay content: 25 to 32 percent
A horizon
Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 through 4 dry and 1 through 3 moist.
Texture of fine earth: clay loam.
Rock fragments: 0 to 7 percent
Clay content: 20 to 27 percent.
Reaction: very strongly to moderately acid.
Bw horizon
Hue: 7.5YR, 10YR or 2.5Y.
Value: 4 through 7 dry, 3 through 6 moist.
Chroma: 3 through 6 dry and 2 through 4 moist.
Texture of fine earth: loam, silty clay loam or clay loam.
Rock fragments: 0 to 10 percent
Clay content: 25 to 40 percent.
Reaction: very strongly to moderately acid.
Redoximorphic features: fine or medium masses of iron accumulation
Quantity: few, common, or many
Hue: 5YR, 7.5YR, 10YR, or 2.5Y
Value: 3 through 6
Chroma: 4 through 8
Redoximorphic features: fine or medium iron depletions
Quantity: few, common or many
Value: 3 through 6
Chroma: 1 or 2
Redoximorphic features in BA horizon are likely a result of liquid manure applications and cattle activity.
Some pedons have C horizons.
C horizon
Hue: 7.5YR, 10YR or 2.5Y.
Value: 4 through 7 dry, 3 through 6 moist.
Chroma: 3 through 6 dry and 2 through 4 moist.
Texture of fine earth: loam, silty clay loam, or clay loam.
Rock fragments: 0 to 35 percent and 0 to 5 percent cobbles.
Pararock fragments: 0 to 10 percent
Clay content: 25 to 40 percent.
Reaction: very strongly to slightly acid.
Redoximorphic features: fine or medium masses of iron accumulation
Quantity: few, common, or many
Hue: 7.5YR, 10YR, or 2.5Y
Value: 3 through 6
Chroma: 4 through 8
Redoximorphic features: fine or medium iron depletions
Quantity: few, common or many
Value: 3 through 6
Chroma: 1 or 2
COMPETING SERIES: This is the Hookton series. Hookton soils have redoximorphic features at 25 to 50 centimeters deep and are somewhat poorly drained.
GEOGRAPHIC SETTING: Carlotta soils are on fluvial terraces. Slopes are 0 to 8 percent. The soils formed in alluvium derived from mixed sources. Elevations are 4 to 32 meters (13 to 105 feet). The climate is humid, characterized by warm wet winters and warm moist summers with fog. A strong marine influence limits the diurnal and annual range of temperature. The mean annual temperature is 11 to 14 degrees C (52 to 57 degrees F). The mean annual precipitation is 1778 to 2286 millimeters (70 to 90 inches). The frost-free period is 270 to 330 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ferndale, Tsunami, and Weott soils. Ferndale soils are fine-silty. Tsunami soils do not have redoximorphic features in the upper 100 centimeters. Weott soils have redoximorphic feature within 10 centimeters of the soil surface. Ferndale soils are on nearby low floodplain steps. Tillas soils are higher up on fluvial terraces. Weott soils are on floodplains.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained; low runoff; moderately low to high saturated hydraulic conductivity; flooding rare.
USE AND VEGETATION: The soils are used mainly for pasture. Native vegetation is redwood, grand fir, Sitka spruce, California laurel, red alder, willow, bigleaf maple, and salmonberry.
DISTRIBUTION AND EXTENT: Coastal Redwood Belts; MLRA 4B. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES PROPOSED: Humboldt and Del Norte Counties, California.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Umbric epipedon - the zone from 0 to 60 centimeters.
2. Cambic horizon - the zone from 33 to 130 centimeters.
3. Particle-size control section - the zone from 25 to 100 centimeters, averages 27 percent clay, and 1 percent rock fragments.
ADDITIONAL DATA:
Type location was move (8/2007) to current location to better represent the series concept. The series description was extensively revised at this time. The classification was also revised from isomesic Fluventic Humic Dystrudepts.
The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as Typic Humitropepts. Competing series were not checked at that time.
Soil classified using the 10th Edition of the Keys to Soil Taxonomy.