LOCATION PAPAC WAEstablished Series
TAXONOMIC CLASS: Medial, ferrihydritic, isomesic Oxyaquic Fulvudands
TYPICAL PEDON: Papac gravelly medial silt loam, forested, on a south facing 11 percent slope under a western hemlock forest at 300 feet elevation. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures. When described the soil was dry to 10 inches and moist below.)
Oi--0 to 3 inches; accumulation of western hemlock needles, twigs and moss, abrupt smooth boundary. (1 to 4 inches thick)
A1--3 to 7 inches; very dark brown (10YR 2/2) gravelly medial silt loam, very dark grayish brown (10YR 3/2) dry; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic and weakly smeary; many very fine, common fine and medium, and few coarse roots; many very fine tubular and interstitial pores; 15 percent rounded gravel; extremely acid (pH 4.2); abrupt smooth boundary. (3 to 5 inches thick)
A2--7 to 15 inches; very dark grayish brown (10YR 3/2) gravelly medial silt loam, brown (7.5YR 4/2) dry; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic and weakly smeary; common very fine, fine, medium and coarse roots; common very fine tubular and interstitial pores; 20 percent rounded gravel; very strongly acid (pH 4.8); clear smooth boundary. (5 to 12 inches thick)
Bw1--15 to 19 inches; dark yellowish brown (10YR 4/4) gravelly medial silt loam, yellowish brown (10YR 5/6) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic and weakly smeary; common very fine and medium and few fine coarse roots; many very fine tubular and interstitial pores; 20 percent rounded gravel; very strongly acid (pH 4.8); clear wavy boundary. (3 to 5 inches thick)
Bw2--19 to 27 inches; brown (7.5YR 4/4) gravelly medial silty clay loam, yellowish brown (10YR 5/6) dry; moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic and weakly smeary; few coarse and common very fine, fine, and medium roots; many very fine tubular and interstitial pores; 25 percent rounded gravel; strongly acid (pH 5.2); clear smooth boundary. (3 to 9 inches thick)
Bw3--27 to 36 inches; yellowish brown (10YR 5/4) gravelly medial silty clay loam, light yellowish brown (10YR 6/4) dry; moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic and weakly smeary; common very fine and fine roots; common very fine tubular and interstitial pores; 25 percent rounded gravel; strongly acid (pH 5.2); abrupt smooth boundary. (4 to 10 inches thick)
2Cd--36 inches; light olive brown (2.5Y 5/4), dense glacial till that crushes to very gravelly sandy loam, light yellowish brown (2.5Y 6/4) dry; massive; hard, firm, nonsticky and nonplastic; 50 percent gravel; moderately acid (pH 5.6).
TYPE LOCATION: Grays Harbor County, Washington; approximately 2 miles east of Moclips along a spur off the Bear Hill Road; 200 feet east and 600 feet north of the SW corner section 10, T.20N., R.12W.
RANGE IN CHARACTERISTICS: Depth to dense till (densic material) is 20 to 40 inches. The mean annual soil temperature is estimated to range from 47 to 51 degrees F. The difference between the mean winter and mean summer soil temperature is 5 to 9 degrees F. The umbric epipedon is 10 to 17 inches thick. The solum has andic soil properties throughout with moist bulk density of 0.75 to 0.90 g/cubic centimeter, phosphate retention of 85 to 100 percent, acid oxalate aluminum plus one-half the iron of 2 to 4 percent and 15 bar water of 25 to 35 percent on air-dried samples. Acid oxalate iron is 1.5 to 3.0 percent.
The A horizon has hue of 7.5YR or 10YR, value of 2 or 3 moist, 3 or 4 dry, and chroma of 2 or 3. The horizon has 15 to 25 percent coarse fragments. It is very strongly acid or extremely acid. It has 7 to 25 percent organic matter.
The Bw horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, 5 or 6 moist, and chroma of 4 through 6. It is gravelly medial silt loam or gravelly medial silty clay loam. This horizon has 15 to 35 percent coarse fragments. It is strongly acid or very strongly acid. It has 4 to 10 percent organic matter.
The 2Cd horizon has hue of 10YR or 2.5Y, value of 4 or 5 moist, 5 or 6 dry, and chroma of 4 through 6. It is dense glacial drift that crushes to very gravelly or extremely gravelly sandy loam or loam. Hard coarse fragments range from 40 to 70 percent by volume.
COMPETING SERIES: These are the similar Copalis, and Oyhut series. All of these soils except Copalis and Oyhut soils are 40 or more inches deep. Copalis and Oyhut soils have cemented materials within 40 inches and have redox features (Aquic).
GEOGRAPHIC SETTING: Papac soils are on glacial terraces and terrace escarpments. Slopes are 1 to 65 percent. These soils formed in weathered glacial drift. Elevation ranges from near sea level to 600 feet. Papac soils are in a humid marine climate with relatively cool, dry summers and cool, wet winters. The annual precipitation ranges from 80 to 100 inches. The mean January temperature is 38 degrees F.; the mean July temperature is 60 degrees F.; and the mean annual temperature is 48 degrees F. The growing season (28 degrees F.) is 140 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Halbert, Mopang, Mudcreek, and Wishkah soils. Halbert soils are poorly drained. Wishkah soils are somewhat poorly drained. Mudcreek soils are medial-skeletal. Mopang soils have cemented materials at 40 to 60 inches.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to medium runoff; permeability is moderate to the dense glacial till and very slow through it. A temporary water table (oxyaquic conditions) is present at 1.5 to 3.5 feet from November through April.
USE AND VEGETATION: Principal uses are timber production, watershed, wildlife habitat, and recreation. The major tree species are western hemlock with scattered Sitka spruce and western red cedar. Understory species include salal, blue and red huckleberry, western swordfern, western brachenfern and deer fern.
DISTRIBUTION AND EXTENT: Grays Harbor County, Washington. MLRA 4A. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grays Harbor County, Washington, 1979.
REMARKS: Diagnostic horizons and other features:
- Umbric epipedon
- Cambic horizon
- Andic soil properties from 3 to 36 inches
- Densic contact at 36 inches
- All depths to diagnostic horizons and features are measured from the top of the first mineral horizon.