LOCATION LOEB                    OR

Established Series
Rev: MHF/RTS/RWL
05/2015

LOEB SERIES

The Loeb series consists of deep, well drained soils that formed in colluvium and residuum derived from metasedimentary or metavolcanic rock types. Loeb soils are on broad ridgetops of coastal hills and mountains. Slopes are 0 to 30 percent. The mean annual precipitation is about 2800 110 inches and the mean annual temperature is about 12 degrees C (54 degrees F).

TAXONOMIC CLASS: Fine, isotic, isomesic Typic Haplohumults

TYPICAL PEDON: Loeb silt loam-woodland, on a 12 percent south-facing slope at an elevation of 178 meters (580 feet). (When described on May 22, 1985, the soil was moist throughout. Colors are for moist soil unless otherwise noted.)

Oi--0 to 5 centimeters; (0 to 2 inches); slightly decomposed litter of needles, leaves, twigs, and woody materials; moderately acid (pH 6.0).

A1--5 to 15 centimeters; (2 to 6 inches); dark reddish brown (5YR 3/3) silt loam, brown (7.5YR 4/4) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and few coarse roots throughout; many fine irregular pores; 10 percent soft rock fragments; very strongly acid (pH 4.8); clear smooth boundary.

A2--15 to 30 centimeters; (6 to 12 inches); dark reddish brown (5YR 3/3) silt loam, brown (7.5YR 4/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and few coarse roots throughout; many fine tubular pores; 5 percent gravel and 10 percent soft rock fragments; very strongly acid (pH 4.8); gradual wavy boundary. (Combined thickness of the A horizon is 7 to 14 inches.)

Bt1--30 to 61 centimeters; (12 to 24 inches); reddish brown (5YR 4/3) silty clay loam, brown (7.5YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and few coarse roots throughout; many fine tubular pores; few distinct clay films on ped faces, common prominent clay films in pores; 5 percent gravel and 15 percent soft rock fragments; very strongly acid (pH 5.0); gradual wavy boundary.

Bt2--61 to 99 centimeters; (24 to 39 inches); reddish brown (5YR 4/4) silty clay, strong brown (7.5YR 5/6) dry; moderate fine subangular blocky structure; slightly hard, friable, sticky and plastic; few medium and coarse roots throughout; many fine tubular pores; many distinct clay films on ped faces and in pores; 5 percent gravel and 20 percent soft rock fragments; very strongly acid (pH 5.0); gradual wavy boundary.

Bt3--99 to 122 centimeters; (39 to 48 inches); reddish brown (5YR 4/4) gravelly clay, strong brown (7.5YR 5/6) dry; weak fine subangular blocky structure; slightly hard, friable, sticky and plastic; few coarse roots throughout; common fine tubular pores; common distinct clay films on ped faces and in pores; 20 percent gravel, 5 percent cobbles, and 30 percent soft rock fragments; very strongly acid (pH 5.0); clear wavy boundary. (Combined thickness of the Bt horizon is 33 to 46 inches.)

Cr--122 to 152 centimeters; (48 to 60 inches); weathered sandstone.

TYPE LOCATION: Curry County, Oregon, located about 1,025 feet south and 1,450 feet east of the northwest corner of sec. 30, T. 40 S., R. 13 W., W.M. (Latitude 42 degrees, 05 minutes, 23 seconds N.; Longitude 124 degrees, 17 minutes, 33 seconds W.)

RANGE IN CHARACTERISTICS:

Soil Temperature: The mean annual soil temperature is 12 to 15 degrees C (54 to 59 degrees F). The difference between mean summer and mean winter soil temperature is 2 to 4 degrees. The soils have an isomesic temperature regime. .

Soil Moisture: The soils are usually moist and are dry for less than 45 consecutive days in all parts between depths of 4 and 12 inches in the four months following the summer solstice. The soils have a udic soil moisture regime.

Umbric epipedon: ranges from 25 to 50 centimeters (10 to 20 inches) thick

Depth to a paralithic contact: is 50 to 100 centimeters. (40 to 60 inches).

Organic Matter: There is 12 to 20 kilograms per square meter of organic carbon.

Reaction: Very strongly acid

Particle-size control section (weighted average):
Rock fragments: 0 to 25 percent gravel, and 15 to 30 percent para-gravel

Clay content: 35 to 45 percent

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 slightly acid.

A horizon
Hue: 5YR or 7.5YR
Value: 2 or 3 moist, 4 or 5 dry
Chroma: 2 or 3 moist, 3 or 4 dry.
Texture of fine earth: silt loam
Rock fragments: 0 to 10 percent gravel, 0 to 20 percent para-gravel
Clay content: 15 to 25 percent.

Bt horizon
Hue: 5YR or 7.5YR
Value: 3 or 4 moist, 5 or 6 dry
Chroma 3 or 4 moist, 4 to 6 dry.
Texture of fine earth: silty clay loam, silty clay, or gravelly clay
Rock fragments: 0 to 20 percent gravel, 0 to 5 percent cobbles, and 15 to 30 percent para-gravel
Clay content: 35 to 45 percent clay

COMPETING SERIES: Competing series include the Bullgulch, Hunterscove, Macklyn, Quinliven, Vandamme, Wadecreek, and Winchuck soils. Bullgulch and Hunterscove soils have a mean annual soil temperature less than 54 degrees F. In addition, Bullgulch soils have an umbric epipedon 20 to 30 inches thick and hue of 10YR throughout the Bt horizon. Hunterscove soils are 20 to 40 inches deep to bedrock. Macklyn soils are 20 to 40 inches deep to a paralithic contact. Quinliven soils have an ochric epipedon (E horizon), and are moderately well drained with redox depletions occurring below 30 inches. Vandamme soils have an ochric epipedon and lack coarse fragments greater than 3 inches in diameter or gravelly textures in the argillic horizon. Wadecreek soils have a mean annual soil temperature less than 54 degrees F. and redox depletions within the lower Bt horizon. Winchuck soils average greater than 45 percent clay in the control section.

GEOGRAPHIC SETTING: Loeb soils are on stable broad ridgetops of coastal hills and mountains. Slopes are 0 to 30 percent. The soils formed in colluvium residuum derived dominantly from metasedimentary or metavolcanic rock types of the Dothan Formation. Elevations are 60 meters to 396 meters (200 to 1,300 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 precipitation is 2286 to 3302(90 to 130 inches). The mean annual temperature is 11 to 14 degrees centigrade (52 to 57 degrees F). The frost-free period is 240 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bosland, Dulandy, Floras, Guerin, Macklyn, Vondergreen, Wedderburn, and Zwagg soils. Bosland, Dulandy, Floras, Guerin, Macklyn, Vondergreen, and Wedderburn soils occur on adjacent ridgetops or side slopes. Zwagg soils are on adjacent grassland areas on ridgetops and side slopes. Bosland, Dulandy, Floras, Guerin, Wedderburn, and Zwagg soils lack argillic horizons. Macklyn soils are 20 to 40 inches deep to a paralithic contact. Vondergreen soils are somewhat poorly drained.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high to moderately low Saturated Hydraulic Conductivity.

USE AND VEGETATION: The soils are used for timber production, homesites, pasture, watershed, recreation, and wildlife habitat. Native vegetation is Douglas-fir, coastal redwood, tanoak, California laurel, evergreen huckleberry, salal, red elderberry, western swordfern, Pacific rhododendron, cascade Oregongrape, common beargrass, and Pacific trillium.

DISTRIBUTION AND EXTENT: Coastal hills and mountains of southwestern Oregon; MLRA 4B. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Curry County, Oregon, 1995.

REMARKS: Diagnostic horizons and features in this pedon include:

Umbric epipedon - the zone from 5 to 30 centimeters (A1, A2 horizons).

Argillic horizon - the zone from 30 to 122 centimeters (Bt1, Bt2, Bt3 horizons).

Particle-size control section - the zone from 30 to 80 centimeters (Bt1 and part of Bt2 horizon).

Depth to a paralithic contact - at 122 centimeters.

NASIS User Pedon Id: 95OR015004

ADDITIONAL DATA: Partial laboratory data is available for this series. Reference sample User Pedon ID S86OR-015-002; KSSL Lab Pedon no. 92PO058 from a similar pedon in Curry County, Oregon, NSSL, Lincoln NE, 1/1986.
Complete characterization data available from a similar pedon: User Pedon ID 92OR015009; KSSL Lab Pedon NO. 92P1058 from Curry County, Oregon, NSSL, Lincoln, NE.

Soil classified using the 11th Edition of the Keys to Soil Taxonomy.

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National Cooperative Soil Survey
U.S.A.