LOCATION MARBLESPRING WATentative Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Typic Xerorthents
TYPICAL PEDON: Marblespring fine gravelly loamy coarse sand, on a 2 percent slope under conifers at an elevation of 1900 feet. (Colors are for dry soil unless otherwise noted. When described on April 15, the soil was moist throughout.)
Oi--0 to 0.5 inches; slightly decomposed needles, leaves and twigs; clear wavy boundary.
A1--0.5 to 2 inches; brown (10YR 5/3) fine gravelly loamy coarse sand, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; soft, very friable, nonsticky and nonplastic; common very fine roots; many fine and very fine interstitial pores; 5 percent subrounded medium gravel and 25 percent subrounded fine gravel; moderately acid (pH 6.0); gradual wavy boundary. (0 to 3 inches thick)
A2--2 to 7 inches; pale brown (10YR 6/3) fine gravelly loamy coarse sand, brown (10YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine few medium roots; many fine interstitial pores; 5 percent subrounded medium gravel and 25 percent subrounded fine gravel; moderately acid (pH 6.0); clear wavy boundary. (3 to 7 inches thick)
E&Bt1--7 to 27 inches; very pale brown (10YR 7/3) very gravelly loamy coarse sand (E Part), brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic; 5 faint irregular wavy 1/8 to 1/4 inch thick yellowish brown (10YR 5/4) lamellae of loamy coarse sand (Bt Part), dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; common fine and medium roots; many fine interstitial pores; 5 percent medium gravel and 35 percent fine gravel; 15 percent clay bridging between sand grains in Bt Part; slightly acid (pH 6.5); gradual wavy boundary.
E&Bt2--27 to 51 inches; very pale brown (10YR 7/3) very gravelly coarse sand (E Part), brown (10YR 4/3) moist; single grain, loose, nonsticky and nonplastic; 8 faint irregular wavy lamellae 1/8 to 1/4 inch thick of coarse sand (Bt Part); single grain; loose, nonsticky and nonplastic; common medium coarse roots; many fine interstitial pores; 10 percent subrounded medium gravel and 35 percent subrounded fine gravel; neutral (pH 6.7); gradual wavy boundary. (combined thickness of the E&Bt horizon is 20 to 45 inches thick)
C--51 to 60 inches; multicolored very gravelly coarse sand; single grain; loose, nonsticky and nonplastic; many medium interstitial pores; 5 percent subrounded medium gravel and 30 percent subrounded fine gravel; neutral (pH 7.0).
TYPE LOCATION: Spokane County, Washington; located about 1 mile northeast of Mead, WA, 2500 feet east and 1700 feet south of the northwest corner of section 26, T. 27 N., R. 43 E; USGS Mead topographic quadrangle; (Latitude 47 degrees, 48 minutes, 42 seconds N. and Longitude 117 degrees, 20 minutes, 12 seconds W.) 474789 meters UTM Easting and 5295222 UTM meters Northing, NAD 27.
RANGE IN CHARACTERISTICS: (Depths to diagnostic horizons and features are measured from the top of the first mineral layer.)
Mean annual soil temperature - 47 to 49 degrees F
Moisture control section - usually moist but are dry between 12 and 35 inches for 75 to 90 consecutive days following the summer solstice
Rock fragment content - 35 to 55 percent in the particle-size control section, dominated by fine gravel
Lime and silica accumulations may occur on the undersides of some gravels.
A horizon
Value - 3 or 4 moist and 5 or 6 dry
Chroma - 2 to 4 moist or dry
Clay content - 5 to 10 percent
Gravel content - 0 to 5 percent medium gravel, and 15 to 30 percent fine gravel
Total rock fragment content - 15 to 35 percent
Reaction - moderately acid or slightly acid
E&Bt horizon
The E Part comprises 90 to 98 percent of the horizon
Value - 5 to 7 dry, 4 or 5 moist
Chroma 3 or 4, dry or moist
Texture - loamy coarse sand or coarse sand with total rock fragment content of 35 to 55 percent
Clay content - averages 5 to 8 percent clay
Gravel content - 0 to 10 percent medium gravel, 30 to 45 percent fine gravel
Cobble content - 0 to 2 percent cobbles.
Reaction - slightly acid or neutral
The Bt part comprises 2 to 10 percent of the horizon and total thickness of the lamellae is less than 6 inches.
Texture - loamy coarse sand or coarse sand.
Clay content - It averages 6 to 10 percent clay.
C horizon
Gravel content - 0 to 5 percent medium gravel, 30 to 45 percent fine gravel
Cobble content - 0 to 2 percent cobbles
Reaction - slightly acid or neutral.
Few faint lamellae may be present in the C horizon in some pedons.
COMPETING SERIES: These are the Atter, Carlsborg, Hoypus, Spens, and Valcreek series. Atter soils are very cobbly or very bouldery throughout, have a mean annual soil temperature of 52 to 59 degrees F., and have no lamellae. Carlsborg soils have 50 to 85 percent rock fragments in the particle-size control section, are dry for 60 to 75 consecutive days, and do not have lamellae. Hoypus soils have albic materials (E horizon) and do not have lamellae. Spens soils do not have lamellae. Valcreek soils are 20 to 40 inches to a paralithic contact.
GEOGRAPHIC SETTING: The Marblespring soils are on outwash terrace treads. Elevations are 1,800 to 2,400 feet. Slope ranges from 0 to 8 percent. The soils formed in sandy and gravelly glaciofluvial deposits from mixed minerology. The climate is characterized by warm dry summers and cool moist winters. The mean annual precipitation is 15 to 22 inches. The mean annual temperature is 46 to 52 degrees F. The frost-free period is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Springdale and Marble soils. Springdale soils occur on terraces and terrace breaks, have a cambic horizon, and do not have lamellae. Marble soils are sandy throughout and occur on dune-like terraces.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained, rapid permeability.
USE AND VEGETATION: These soils are used for urban development, rural homesites, recreation, water supply, and wildlife habitat. Potential natural vegetation is mainly widely spaced ponderosa pine, with an understory of bluebunch wheatgrass, lupine, eriogonum and arrowleaf balsamroot.
DISTRIBUTION AND EXTENT: Northeastern Washington; MLRA 9. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Spokane County, Washington, 1999. The name is coined.
REMARKS: Diagnostic horizons and features in this pedon include:
Ochric epipedon - the zone from a depth of 0.5 to 7 inches (A horizon).
Particle-size control section - the zone from 10.5 to 40.5 inches (parts of the E&Bt1, and E&Bt2 horizons)
This series concept would classify as a lamellic subgroup of Xerorthents if such a subgroup were in existence in Soil Taxonomy.