LOCATION MORANCREEK WA

Established Series
Rev. MPR/JDO/SBC
06/2011

MORANCREEK SERIES

The Morancreek series consists of very deep, moderately well drained soils formed in colluvium from glacial drift and metasedimentary bedrock. Morancreek soils are on hillslopes and mountain slopes. Slope ranges from 5 to 25 percent. The mean annual precipitation is about 838 millimeters and the mean annual air temperature is about 9 degrees C.

TAXONOMIC CLASS: Coarse-loamy, isotic, mesic Aquic Humixerepts

TYPICAL PEDON: Morancreek sandy loam, forested, on a northeast-facing sideslope of 8 percent at 90 meters elevation. When described on October 3, 2005 the soil was slightly moist to 8 cm and dry below. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 3 cm; slightly decomposed needles, leaves, and twigs; abrupt smooth boundary.

A--3 to 8 cm; dark grayish brown (10YR 4/2) sandy loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; many very fine and fine roots and common medium roots; many very fine and fine irregular pores; moderately acid (pH 5.6); clear wavy boundary. (5 to 18 cm thick)

Bw1--8 to 25 cm; brown (7.5YR 5/4) sandy loam, dark brown (7.5YR 3/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; few fine roots and many medium roots and common coarse roots; many very fine and fine irregular pores; moderately acid (pH 5.8); gradual wavy boundary.

Bw2--25 to 53 cm; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; soft, friable, nonsticky, nonplastic; few fine and coarse roots and common medium roots; many very fine and fine irregular pores; moderately acid (pH 5.8); gradual wavy boundary. (Combined thickness of Bw horizons is 45 to 81 cm)

Bg--53 to 71 cm; grayish brown (10YR 5/2) sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, nonsticky, nonplastic; few medium and coarse roots; few very fine and fine irregular pores; common medium prominent irregular very weakly cemented dark yellowish brown (10YR 4/6) moist, and yellowish brown (10YR 5/6) dry, iron-manganese masses with diffuse boundaries throughout; common medium faint irregular very weakly cemented dark gray (10YR 4/1) moist, gray (10YR 6/1) dry, iron depletions with diffuse boundaries throughout; 5 percent gravel; moderately acid (pH 6.0); gradual wavy boundary. (15 to 53 cm thick)

C--71 to 152 cm; light brownish gray (10YR 6/2) sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, nonsticky, nonplastic; few fine roots; few fine tubular and many very fine irregular pores; many medium prominent irregular very weakly cemented dark yellowish brown (10YR 4/6) moist, and yellowish brown (10YR 5/6) dry, iron-manganese masses with diffuse boundaries throughout; slightly acid (pH 6.2).

TYPE LOCATION: San Juan Island, San Juan County, Washington; located about 740 meters west and 140 meters south of the northeast corner of section 13, T. 35N., R. 4W. Willamette Baseline Meridian; USGS Roche Harbor SE quarter quadrangle; Latitude 48 degrees 38 minutes and 53 seconds North, Longitude 122 degrees 48 minutes and 35 seconds West.

RANGE IN CHARACTERISTICS: Depths to diagnostic horizons and features start from the mineral soil surface.

Mean annual soil temperature - 10 to 11 degrees C
Depth to redoximorphic features - 38 to 75 cm
Reaction - moderately acid to slightly acid
Particle size control section:
Clay content - 4 to 17 percent
Rock fragments - 0 to 35 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones, 0 to 35 percent total

A horizon
Value - 2 or 3 moist, 3 to 5 dry
Chroma - 2 to 4 moist, 2 to 4 dry
Clay content - 4 to 12 percent

Bw horizons
Hue - 10YR or 7.5YR
Value - 3 or 4 moist, 4 or 5 dry
Chroma - 2 to 6 moist or dry
Texture - SL, L or SIL
Clay content - 4 to 14 percent
Rock fragments - 0 to 25 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones

Bg horizon
Value - 3 or 4 moist, 4 to 6 dry
Chroma - 2 to 4 moist or dry
Texture - SL, COSL or LFS
Clay content - 5 to 14 percent
Rock Fragments - 5 to 35 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones

C horizon
Value - 4 or 5 moist, 6 or 7 dry
Texture - SL, COSL or LFS
Clay content - 4 to 12 percent
Rock Fragments - 0 to 35 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones

COMPETING SERIES: These are the Roche and Zylstra (T) series. Roche and Zylstra soils formed in glacial drift over dense glaciomarine deposits, and have a densic contact at a depth of 50 to 100 cm.

GEOGRAPHIC SETTING: Morancreek soils occur on hillslopes and mountain slopes. Slope ranges from 5 to 25 percent and elevations range from 0 to 732 meters. These soils formed in colluvium from glacial drift and bedrock of metasedimentary lithology. The climate is characterized by warm, dry summers and mild, moist winters. The mean annual precipitation is 635 to 1,016 millimeters. The mean annual air temperature is 9 to 10 degrees C. The frost-free season is 200 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cady, Deadmanbay, and Doebay series. Cady soils occur on adjacent hillslopes and mountain slopes and have a lithic contact between 25 and 50 cm. Deadmanbay soils occur in valleys on outwash plains in a lower landscape position than Morancreek soils. Deadmanbay soils have a fine-loamy particle-size control section and have a densic contact between 100 and 150 cm. Doebay soils occur on adjacent hillslopes and mountain slopes, have a lithic contact between 50 and 100 cm and have a loamy-skeletal particle-size control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained; Saturated hydraulic conductivity is high. Morancreek soils have a water table as high as 53 cm during January and February, and as high as 71 cm during March.

USE AND VEGETATION: Used for timber production, recreation, wildlife habitat, homesites, and watershed. Potential natural vegetation is an overstory of western redcedar, Douglas-fir, grand fir, lodgepole pine, and red alder, with an understory of common snowberry, trailing blackberry, salmonberry, stinging nettle, salal, swordfern, and bracken fern.

DISTRIBUTION AND EXTENT: Northwest Washington; MLRA A2, Northern Part. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: San Juan County, Washington, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - 3 to 53 cm (A and Bw horizons)
Cambic horizon - 53 to 71 cm (Bg horizon)
Particle-size control section - 28 to 103 cm
Depth to Redoximorphic features - 53 cm

National Cooperative Soil Survey
U.S.A.