LOCATION PICKETT WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Andic Dystroxerepts
TYPICAL PEDON: Pickett very gravelly loam, forested, on a northeast-facing sideslope of 45 percent at 380 meters elevation. (Colors are for moist soil unless otherwise noted. When described on August 19, 2004 the soil was moist throughout.)
Oi--0 to 3 cm; slightly decomposed plant material; abrupt wavy boundary. (3 to 5 cm thick)
A--3 to 8 cm; dark grayish brown (10YR 4/2) very gravelly loam, dark yellowish brown (10YR 4/4) dry; moderate fine subangular blocky structure; slightly hard, firm, nonsticky and nonplastic; common medium and coarse roots, few very coarse roots, and many very fine and fine roots; few very fine and fine interstitial and irregular pores, and common very fine and fine tubular pores; 35 percent gravel and 15 percent cobbles; NaF pH 9.3; strongly acid (pH 5.4); gradual wavy boundary. (5 to 15 cm thick)
Bw1--8 to 69 cm; dark brown (7.5YR 3/4) very gravelly fine sandy loam, strong brown (7.5YR 5/6) dry; moderate medium subangular blocky structure; soft, friable, nonsticky and nonplastic; many very fine and fine roots, common medium and coarse roots, and few very coarse roots; few very fine and fine interstitial and irregular pores, and common very fine and fine tubular pores; 30 percent gravel, 15 percent cobbles; NaF pH 10.8; moderately acid (pH 5.6); clear wavy boundary. (15 to 64 cm thick)
Bw2--69 to 91 cm; olive brown (2.5Y 4/4) very gravelly coarse sandy loam, light olive brown (2.5Y 5/4) dry; weak fine subangular blocky structure; soft, friable, nonsticky and nonplastic; many very fine roots, common fine roots, and few medium and coarse roots; common very fine and fine irregular pores; 40 percent gravel and 10 percent cobbles; NaF pH 10.8; moderately acid (pH 5.6); abrupt wavy boundary. (18 to 46 cm thick)
R--91 cm; metasedimentary bedrock
TYPE LOCATION: Orcas Island, San Juan County, Washington; 19 meters south and 152 meters west of the northeast corner of sec. 34, T. 37 N., R. 1 W. Willamette Meridian. USGS Mount Constitution SE quarter quadrangle; lat. 48 degrees 40 minutes 8 seconds N. and long. 122 degrees 50 seconds W.
RANGE IN CHARACTERISTICS: Depths to diagnostic horizons and features start from the mineral soil surface.
Mean annual soil temperature - 9 to 10 degrees C.
Soil moisture control section - dry 45 to 60 days following summer solstice
Depth to lithic contact - 50 to 100 cm
Reaction - strongly acid to moderately acid
Particle size control section:
Clay content - 5 to 18 percent
Rock fragments - 35 to 70 percent
A horizon
Value - 2 or 3 moist
Chroma - 1 to 3 moist, 3 or 4 dry
Rock fragments - 35 to 60 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones, 35 to 60 percent total
Ammonium oxalate extractable aluminum plus one half iron - 1.5 to 2.5 percent
Bulk Density - 0.8 to 1.0 g/cm3
Phosphorous retention - 50 to 80 percent
Volcanic glass - 0 to 4 percent
Rock fragments - 35 to 60 percent gravel, 0 to 20 percent cobbles,
Bw1 horizon
Hue - 10YR to 7.5YR
Value - 3 or 4 moist, 5 to 6 dry
Chroma - 3 to 6 moist or dry
Texture - Ashy-L, Ashy-SL, or Ashy-FSL
Rock fragments - 35 to 60 percent gravel, 0 to 20 percent cobbles, 0 to 10 percent stones, 35 to 70 percent total
Ammonium oxalate extractable aluminum plus one half iron - 1.5 to 2.5 percent
Bulk Density - 0.8 to 1.0 g/cm3
Phosphorous retention - 50 to 80 percent
Volcanic glass - 0 to 4 percent
Bw2 horizon
Hue - 2.5Y to 10YR
Value - 3 or 4 moist, 4 to 6 dry
Chroma - 3 to 6 moist or dry
Texture - SL, or COSL
Rock fragments - 35 to 60 percent gravel, 0 to 20 percent cobbles, 0 to 10 percent stones, 35 to 70 percent total
COMPETING SERIES: These are the Lydon, Lyre, McElroy, Ovall, Schneider, Siouxon, and Yedlick series. Lydon soils formed in weathered tephra over residuum and colluvium weathered from igneous rock, have a mean annual soil temperature ranging from 11 to 15 degrees C, and are dry in the soil moisture control section for more than 60 days. Lyre soils formed in glacial outwash and are very deep. McElroy soils are very deep, have an umbric epipedon, and formed in colluvium and residuum from basalt. Ovall soils formed in glacial drift mixed with residuum and colluvium from andesite and breccia, and have an umbric epipedon. Schneider and Siouxon soils are 100 to 150 cm deep to a lithic contact and have an umbric epipedon. Yedlick soils do not have a lithic contact, are formed in colluvium and residuum from basalt, and are dry in the soil moisture control section for 60 to 75 days.
GEOGRAPHIC SETTING: Pickett soils occur on hillslopes and mountain slopes. Slopes range from 5 to 75 percent and elevations range from 0 to 732 meters. These soils formed in colluvium from glacial drift, bedrock of metasedimentary lithology, and volcanic ash. The climate is characterized by warm, dry summers and mild, moist winters with intermittent snow cover. The annual precipitation ranges from 890 to 1,140 millimeters. Mean annual air temperature ranges from 8 to 9 degrees C. The frost-free season is 160 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Constitution, Kahboo, Skipjack, and Kickerville series. Constitution soils have less than 35 percent rock fragments in the particle-size control section and occur on adjacent hillslopes and mountain slopes. Kahboo soils have a lithic contact between 25 and 50 cm and occur on summits, hillslopes, and mountain slopes. Skipjack soils do not have a lithic contact, have less than 35 percent rock fragments in the particle-size control section, and occur on adjacent hillslopes and mountain slopes. Kickerville soils formed in loess and glacial outwash, do not have a lithic contact, and occur on outwash terraces.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Saturated hydraulic conductivity is high.
USE AND VEGETATION: Used for timber production, recreation, wildlife habitat, homesites, and watershed. Potential natural vegetation consists of western hemlock, Douglas-fir, western redcedar, Cascade Oregongrape, prickly currant, false Solomons-seal, 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, 1956. The name is taken from Mount Pickett on Orcas Island.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Andic subgroup properties - 3 to 69 cm (A and Bw1 horizons)
Cambic horizon - 8 to 91 cm (Bw horizons)
Lithic contact - 91 cm (top of the R horizon)
Particle-size control section - 28 to 91 cm
Bulk density in the A and Bw1 horizons is assumed to be less than 1 g/cm3
This revision (5/2006) reflects a change in the typical pedon from Whatcom County to San Juan County, Washington.
ADDITIONAL DATA: Reference sample - National Soil Survey Laboratory pedon number 03N0240.