LOCATION ETELKA OREstablished Series
TAXONOMIC CLASS: Fine, isotic, mesic Oxyaquic Dystrudepts
TYPICAL PEDON: Etelka silt loam - forested regrowth after clearcut. (Colors are for moist soil unless otherwise noted.)
A--0 to 13 inches; dark grayish brown (2.5Y 4/2) silt loam, light brownish gray (2.5Y 6/2) dry; moderate fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine to medium roots; many very fine and fine tubular and irregular pores; 2 percent gravel; strongly acid (pH 5.4); clear wavy boundary. (8 to 14 inches thick)
BA--13 to 24 inches; dark brown (10YR 4/3) silt loam, brown and pale brown (10YR 5/3, 6/3) dry; moderate fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine to medium roots; many very fine and fine tubular and irregular pores; 4 percent gravel; strongly acid (pH 5.2); gradual smooth boundary. (9 to 12 inches thick)
Bw1--24 to 32 inches; olive brown (2.5Y 4/4) silty clay loam, light olive brown (2.5Y 5/4) dry; moderate medium subangular blocky structure; very hard, friable, sticky and plastic; many fine and medium roots; common very fine and fine tubular and irregular pores; few fine faint redox concentrations below 28 inches; 6 percent gravel; strongly acid (pH 5.4); gradual smooth boundary. (6 to 10 inches thick)
Bw2--32 to 45 inches; olive brown and dark grayish brown (2.5Y 4/4, 4/2) silty clay, light olive brown and light brownish gray (2.5Y 5/4, 6/2) dry; moderate coarse subangular blocky structure; extremely hard, firm, very sticky and very plastic; common fine and medium roots; common very fine and fine irregular pores; common fine distinct yellowish brown (10YR 5/8) masses of iron accumulation; 8 percent gravel; strongly acid (pH 5.4); clear wavy boundary. (8 to 15 inches thick)
BC--45 to 60 inches; olive brown and dark grayish brown (2.5Y 4/4, 4/2) silty clay, light olive brown and light brownish gray (2.5Y 5/4, 6/2) dry; moderate coarse subangular blocky structure; extremely hard, firm, very sticky and very plastic; few very fine to medium roots; few very fine and fine irregular pores; many medium distinct gray (10YR 6/1) redox depletions and strong brown (10YR 5/8, 7.5YR 6/5) masses of iron accumulation; moderately acid (pH 5.6).
TYPE LOCATION: Coos County, Oregon; approximately 4 miles west of Powers, Oregon; in the west side road cut of BLM road, south of the Baker quarry; about 900 feet north, 2500 feet west of the SE corner of section 17, T. 31 S., R. 12 W.
RANGE IN CHARACTERISTICS: The soil is usually moist but is dry in the control section for a period of less than 45 consecutive days following the summer solstice. The mean annual soil temperature is 47 to 56 degrees F. Depth to bedrock is more than 60 inches. The amount of hard and partially weathered rock fragments in the control section ranges from 2 to 10 percent gravel and 0 to 5 percent cobbles. Solum thickness is greater than 40 inches.
The A horizon has hue of 2.5Y to 5YR, value of 3 or 4 moist, 5 or 6 dry and chroma of 2 or 3 moist and dry. It is silt loam with 20 to 25 percent clay and 0 to 5 percent gravel. There is evidence of fire in charcoal flecks or burnt peds as shot in some pedons.
The BA horizon has hue of 2.5Y to 5YR, value of 4 or 5 moist, 5 or 6 dry and chroma of 3 to 6 moist and dry. It is silty clay loam or silt loam with 25 to 40 percent clay. It has 0 to 10 percent gravel and 0 to 3 percent cobbles.
The Bw horizon has hue of 7.5YR to 2.5Y, value of 4 or 5 moist, 5 or 6 dry, and chroma of 3 through 6 dry and moist. It is silty clay loam, silty clay, or clay with 35 to 60 percent clay. It has 0 to 10 percent gravel and 0 to 3 percent cobbles. Distinct to prominent redox concentrations are at a depth of 24 to 40 inches.
The BC horizon or C horizon, when present, has hue of 2.5Y to 7.5YR, value of 4 to 6 moist, 5 to 7 dry and chroma of 2 through 4 moist and dry. . It is silty clay loam or clay with 35 to 60 percent clay. It has 0 to 10 percent gravel and 0 to 3 percent cobbles. It commonly has redox depletions and concentrations with hue of 5YR through 5Y, value of 4 through 7, and chroma of 1 through 8 moist and dry. Few to common slickensides may occur in this horizon.
COMPETING SERIES: There are no completing series.
GEOGRAPHIC SETTING: Etelka soils are on foot slopes, ridgetops, and side slopes of mountains. Elevations are 50 to 2500 feet. Slopes are 7 to 70 percent. The soils have formed in fine and moderately fine textured colluvium, and residuum weathered from highly fractured and intensely sheared sedimentary and metasedimentary rocks of Jurassic Age (mostly the Otter Point Formation). The climate is characterized by warm, wet winters and hot, dry summers. The mean January temperature is 43 degrees F. and the mean July temperature is 62 degrees F. The mean annual temperature is 45 to 54 degrees F. The mean annual precipitation is typically 60 to 90 inches. In the interior mountains of Curry County, Oregon, the mean annual precipitation ranges to 130 inches. The frost-free season is 120 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bohannon, Digger, Orford, Preacher, Remote, Rinearson, and Whobrey series. All of these soils occur on ridgetops, foot slopes, or side slopes of mountains. Digger soils have more than 35 percent rock fragments in the particle-size control section and are 20 to 40 inches deep to a paralithic contact. Bohannon, Preacher, and Rinearson soils have an umbric epipedon. Also, Bohannon soils are 20 to 40 inches deep to a paralithic contact. Orford soils have an argillic horizon. Remote soils are loamy-skeletal. Whobrey soils are fine-silty over clayey and are somewhat poorly drained.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow permeability. A perched water table is as high as a depth of 2 to 3 feet from the surface at some time between November and April.
USE AND VEGETATION: These soils are used for timber production, pasture, recreation, watershed, wildlife, and urban growth. The native vegetation is Douglas fir, grand fir, western hemlock, western redcedar, red alder, Port Orford cedar, salal, red huckleberry, evergreen huckleberry, Pacific rhododenron, gooseberry, salmonberry, manzanita, wild iris, and western swordfern. In the interior mountains of Curry County, Oregon, native vegetation also includes tanoak, bigleaf maple, and canyon live oak.
DISTRIBUTION AND EXTENT: Mountains of the southern Oregon Coast Range, principally in the Klamath Mountains; MLRA 1. The series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Coos County, Oregon, 1983.
REMARKS: This draft reflects a change in classification from Typic to Oxyaquic Dystrudepts based on revision to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon include:
ochric epipedon
Cambic horizon - from 13 to 60 inches (BA, Bw1, Bw2, and BC horizons)
PSCS- from 10 to 40 inches.