LOCATION GUERIN OR
Established Series
Rev: MHF/RTS/RWL/SAA
03/2013
GUERIN SERIES
The Guerin series consists of shallow, well drained soils that formed in colluvium and residuum from metasedimentary or metavolcanic rock types. Guerin soils are on narrow ridgetops and side slopes of coastal hills and mountains. Slopes are 0 to 90 percent. The mean annual precipitation is about 110 inches and the mean annual temperature is about 54 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, isotic, isomesic Lithic Humudepts
TYPICAL PEDON: Guerin very gravelly loam, woodland, on a 60 percent southeast-facing slope at an elevation of 500 feet. (Colors are for moist soil unless otherwise noted.)
Oi--1 inch to 0; partially decomposed needles, twigs, and woody materials.
A--0 to 4 inches; very dark grayish brown (10YR 3/2) very gravelly loam, brown (10YR 4/3) dry; strong fine granular structure; slightly hard, friable, nonsticky and nonplastic; many fine and very fine roots; many fine and very fine irregular pores; 25 percent gravel and 15 percent cobbles; strongly acid (pH 5.4); clear smooth boundary. (3 to 6 inches thick)
Bw1--4 to 9 inches; dark brown (7.5YR 3/3) very cobbly loam, brown (7.5YR 5/4) dry; strong very fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many fine and very fine roots; many fine and very fine continuous tubular pores; 30 percent gravel and 20 percent cobbles; strongly acid (pH 5.2); clear wavy boundary.
Bw2--9 to 16 inches; brown (7.5YR 4/4) extremely cobbly loam, strong brown (7.5YR 5/6) dry; moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; many very fine continuous tubular pores; 40 percent gravel and 25 percent cobbles; strongly acid (pH 5.2); gradual wavy boundary. (Combined thickness of the Bw horizon ranges from 7 to 14 inches)
2R--16 inches; fractured sandstone.
TYPE LOCATION: Curry County, Oregon; located about 425 feet north and 2250 feet west of the SE corner of section 4, T. 41 S., R. 13 W. W.M.(Latitude 42 degrees, 03 minutes, 04 seconds N, Longitude 124 degrees, 14 minutes, 56 seconds W)
RANGE IN CHARACTERISTICS: The soils are usually moist and are dry less than 45 consecutive days between 4 and 12 inches following the summer solstice. The mean annual soil temperature is 54 to 59 degrees F. The difference between the mean summer and mean winter soil temperature varies from 5 to 9 degrees F. The particle-size control section averages 15 to 25 percent clay and 50 to 85 percent rock fragments. The solum has hue of 7.5YR or 10YR and has 4 to 8 kilograms of organic carbon per square meter of soil to a depth of one meter. Depth to bedrock is 10 to 20 inches.
The A horizon has value of 3 or 4 moist and dry and chroma of 2 or 3 moist and 3 or 4 dry. It is very gravelly loam with 10 to 20 percent clay. It has 25 to 40 percent gravel and 10 to 20 percent cobbles.
The Bw horizon has value of 3 to 6 moist and dry and chroma of 3 to 6 moist and dry. It is a very cobbly loam or extremely cobbly loam with 15 to 25 percent clay. It has 30 to 50 percent gravel and 20 to 35 percent cobbles.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Guerin soils are on narrow ridgetops and side slopes of coastal hills and mountains. Slopes are 0 to 90 percent slopes. Elevations are 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 90 to 130 inches. The mean annual temperature is 52 to 57 degrees F. The frost-free period is 240 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Bosland,
Dulandy,
Floras,
Loeb,
Macklyn,
Vondergreen,
Wedderburn, and
Zwagg soils. Bosland, Dulandy, Floras, Loeb, Macklyn, and Vondergreen soils are on adjacent side slopes and ridgetops. Wedderburn and Zwagg soils are on adjacent lower coastal hills. Bosland, Dulandy, and Zwagg soils are 20 to 40 inches deep to bedrock. Floras and Wedderburn soils are 40 to 60 inches deep to bedrock. Loeb, Macklyn, and Vondergreen soils have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: The soils are used mainly for timber production, watershed, recreation, and wildlife habitat. Native vegetation is Douglas fir, redwood, tanoak, golden chinkapin, California laurel, red alder, western swordfern, evergreen huckleberry, red huckleberry, Pacific poison oak, trailing blackberry, and salal.
DISTRIBUTION AND EXTENT: Coastal hills and mountains of southwestern Oregon; MLRA 4. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Curry County, Oregon; 1995. The source of the name is a creek in Curry County, Oregon.
REMARKS: This classification was updated in March of 2013 using the Eleventh edition of Soil Taxonomy. This series was formerly classified as loamy-skeletal, mixed, superactive, isomesic Lithic Dystropepts. Competing series were not checked at this time.
Minerology changed from mixed to isotic 1/2000, competing series not updated at that time.
Diagnostic horizons and features recognized in this pedon include:
Umbric epipedon - from the surface to a depth of 9 inches. (A, Bw1 horizons)
Cambic horizon - from a depth of 9 to 16 inches. (Bw2 horizon)
Lithic feature - lithic bedrock at 16 inches (2R horizon)
Particle-size control section - from 10 to 16 inches. (Bw2 horizon)
National Cooperative Soil Survey
U.S.A.