LOCATION SPANA                   WA

Established Series
Rev. AZ/CAB
05/2012

SPANA SERIES

The Spana series consists of very deep, somewhat poorly drained soils formed in glacial outwash. Slopes are 0 to 3 percent. They are in depressions or troughs on terraces. The mean annual precipitation is about 890 mm. The mean annual air temperature is about 11 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Oxyaquic Humixerepts

TYPICAL PEDON: Spana gravelly loam - grass (Colors are for moist soil unless otherwise noted.)

A--0 to 61 cm; very dark brown (10YR 2/2) gravelly loam, dark grayish brown (10YR 4/2) dry; weak fine granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine roots; 15 percent gravel; moderately acid; abrupt smooth boundary. (28 to 71 cm thick)

Bw--61 to 74 cm; very dark grayish brown (10YR 3/2) gravelly loam, grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; hard, firm, sticky, plastic; few very fine roots; 20 percent gravel and 5 percent cobbles; moderately acid; clear smooth boundary. (8 to 43 cm thick)

2Cl--74 to 91 cm; dark grayish brown (10YR 4/2) extremely gravelly coarse sandy loam, light brownish gray (10YR 6/2) dry; massive; soft, very friable, nonsticky, nonplastic; few fine roots; 60 percent gravel and 10 percent cobbles; moderately acid; clear smooth boundary. (18 to 38 cm thick)

2C2--91 to 150 cm; dark grayish brown (10YR 4/2) extremely gravelly loamy sand, light brownish gray (10YR 6/2) dry; massive; loose; 60 percent gravel and 10 percent cobbles; moderately acid.

TYPE LOCATION: Pierce County, Washington; 457 meters west and 853 meters north of the southeast corner of section 27, T. l8 N., R. 3 E.

RANGE IN CHARACTERISTICS:
Umbric epipedon - 50 to 90 cm thick
Particle-size control section:
Weighted average clay percentage - 5 to 15 percent
Weighted average rock fragments - 35 to 50 percent
Mean annual soil temperature - 9 to 12 degrees C.
Moisture control section - dry for 45 to 60 consecutive days following summer solstice

A horizon
Hue - 10YR
Value - 2 to 4 dry
Chroma - 1 or 2 moist or dry
Texture - L or SL
Rock fragments - 0 to 35 percent total, 0 to 35 percent gravel, 0 to 5 percent cobbles

Bw horizon
Hue - 10YR
Value - 3 to 5 moist
Texture - L or SL
Clay percentage - 5 to 18 percent
Rock fragments - 20 to 50 total, 20 to 45 percent gravel, 0 to 20 percent cobbles

2C horizon
Hue - 10YR
Value - 3 to 5 moist and 4 to 6 dry
Chroma - 2 to 4 moist or dry
Texture - COSL, LS, or SL
Rock fragments - 45 to 80 total, 35 to 65 percent gravel, 0 to 25 percent cobbles, 0 to 5 percent stones.

COMPETING SERIES: There are no competing series in this family.

GEOGRAPHIC SETTING: Spana soils are in slightly concave depressions or troughs on glacial outwash terraces at elevations of about 30 to 150 meters. Slopes are 0 to 3 percent. These soils formed in glacial outwash. They occur in a maritime climate with cool dry summers and mild wet winters. The mean annual precipitation is 635 to 1,150 mm. The mean annual temperature is about 11 degrees C., and the frost free period is about 165 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nisqually and Spanaway soils. Nisqually soils are sandy. Spanaway soils are sandy-skeletal.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained; very slow runoff, moderately high saturated hydraulic conductivity. Flooding is likely from November through April.

USE AND VEGETATION: Most areas are in pasture or used for wildlife habitat. Native vegetation is Douglas-fir, western redcedar, red alder, bigleaf maple and a few Oregon white oak and cottonwood with an understory of grass, western brackenfern, salal, Oregon-grape and black hawthorne.

DISTRIBUTION AND EXTENT: Western Washington; MLRA 2. Series is of small extent.

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

SERIES ESTABLISHED: Pierce County, Washington, l974.

REMARKS: Diagnostic horizons and other features;
Umbric epipedon: 0 to 74 cm.
Weighted average rock fragment content in the PSCS (25-100 cm): 41 percent
Classification changed 09/2011 from medial-skeletal over sandy or sandy-skeletal, amorphic over isotic, mesic Pachic Melanoxerands to loamy-skeletal, isotic, mesic Oxyaquic Humixerepts based on the lack andic soil properties in the upper part.

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National Cooperative Soil Survey
U.S.A.