LOCATION SOUTHPLATTE CO
Tentative Series
PRR
02/2025
SOUTHPLATTE SERIES
Depth class: Deep and very deep
Drainage class: Well drained
Saturated hydraulic conductivity: High
Parent material: Thin human-transported material over fine-loamy eolian deposits derived from glaciofluvial sources
Geomorphic location: Human-transported fill on plains mantled with mixed eolian deposits
Slope range: 0 to 3 percent
Mean annual temperature: 11.0 degrees C (51.8 degrees F)
Mean annual precipitation: 406 millimeters (16.0 inches)
Taxonomic Class:
Fine-loamy, mixed, superactive, mesic Aridic Haplustepts
Typical Pedon:
Southplatte loam in urban, park. (Colors are for dry soil unless otherwise noted.)
^A--0 to 18 cm; brown (10YR 4/3) loam, very dark grayish brown (10YR 3/2) moist; weak medium fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; noneffervescent, neutral (pH 7.2); clear wavy boundary.
2Bwb-18 to 33 cm; yellowish brown (10YR 5/4) sandy loam, brown (10YR 4/3) moist; weak coarse subangular blocky structure, soft, very friable, non-sticky, non-plastic; 2 percent fine gravel; noneffervescent; neutral (pH 7.3); clear wavy boundary.
^2Bkb--33 to 78 cm; brown (10YR 5/3) sandy loam, brown (10YR 4/3); weak coarse subangular block structure; slightly hard, friable, non-sticky, non-plastic; finely disseminated free carbonates and 2 percent medium, irregular carbonates masses throughout the matrix; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary.
2C1-78 to 107 cm; yellowish brown (10YR 5/4) sandy loam, dark yellowish brown (10YR 4/4) moist; massive, slightly hard, friable, slightly sticky, slightly plastic; noneffervescent; neutral (pH 7.4); gradual way boundary.
2C2--107 to 135 cm; yellowish brown (10YR 5/6) sandy clay loam, yellowish brown (10YR 5/4); massive; soft, very friable, non-sticky, non-plastic; few fine roots; noneffervescent; neutral (pH 7.2).
2C3--135 to 200 cm; brownish yellow (10YR 6/6) fine sandy loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable, non-sticky, non-plastic; noneffervescent; neutral (pH 6.8).
Type Location:
Denver County, CO
USGS Quadrangle: Commerce City
Latitude: 39.7608806
Longitude: -104.9762417
Datum: WGS84
Coordinates sources: Hand-held GPS
Range in Characteristics:
Depth to free carbonates-25 to 75 centimeters
Thickness of human-transported material-less than 50 centimeters
Particle-size control section (weighted average):
Clay content-18 to 32 percent
Sand content--18 to 45 percent
Total rock fragments--0 to 8 percent
^A horizon:
Hue-7.5YR or 10YR
Value-3 to 5 dry; 1 to 3 moist
Chroma-3 or 4 dry; 2 to 4 moist
Texture (less than 2 mm fraction)--Clay loam, silty clay loam, loam
Clay content--22 to 35 percent
Rock fragments--0 to 8 percent gravel
Reaction--pH 7.0 to 7.8
Thickness--5 to 20 centimeters
^C or Cu horizon(s) (where present):
Hue--10YR
Value-4 or 5 dry or moist
Chroma-4 or 5 dry or moist
Texture (less than 2 mm fraction)-Clay loam, sandy clay loam, sandy loam
Clay content--25 to 35 percent
Rock fragments--3 to 20 percent gravel
Artifacts--0 to 5 percent
Reaction--pH 7.2 to 8.2
Thickness--10 to 25 centimeters
^2Bwb horizon(s):
Hue--10YR
Value-5 or 6 dry; 3 to 4 moist
Chroma-3 or 4 dry; 3 to 5 moist
Texture (less than 2 mm fraction)-Clay loam, sandy clay loam, sandy loam
Clay content-20 to 35 percent
Rock fragments--0 to 3 percent gravel
Reaction--pH 7.0 to 7.8
Thickness--15 to 45 centimeters
^2Bkb horizon(s):
Hue--10YR
Value-5 to 7 dry; 3 to 4 moist
Chroma-3 to 5 dry; 3 to 4 moist
Texture (less than 2 mm fraction)-Clay loam, sandy clay loam, silty clay loam
Clay content-28 to 35 percent
Rock fragments--0 to 12 percent gravel
Reaction--pH 7.4 to 8.4
Thickness--15 to 50 centimeters (combined)
2C horizon(s):
Hue-2.5Y or 10YR
Value-5 or 6 dry; 4 or 5 moist
Chroma-3 to 5 dry; 4 or 5 moist
Texture (less than 2 mm fraction)-Clay loam, sandy clay loam, sandy loam
Clay content--12 to 35 percent
Rock fragments--0 to 5 percent gravels
Reaction--pH 7.2 to 8.4
Thickness--25 to 65 centimeters
Competing Series: These are the Atchison, Berthoud, Fairden, Kachina, McRae, Redmountain, Sixmile series, Teromote, and Ziggy series. None of these series has an ^A horizon.
Geographic Settings:
Parent material- Thin human-transported material over fine-loamy eolian deposits derived from glaciofluvial sources
Landform--Human-transported fill on plains mantled with mixed eolian deposits
Slope ranges--0 to 3 percent
Mean annual air temperature--10.0 to 12.0 degrees C (50.0 to 53.6 degrees F)
Mean annual precipitation range--356 to 432 millimeters (14.0 to 17.0 inches)
Frost-free period--135 to 165 days
Elevation--1,580 to 1,720 meters (~5,185 to 5,645 feet)
Climate--continental, temperate, semi-arid; very cold and snowy winters; cool, moist springs, hot summers, with North American monsoon precipitation from July through August.
Geographically Associated Soils: Globeville soils: Found on adjacent stream terraces and has fine-loamy particle size control section
Drainage and Saturated Hydraulic Conductivity:
Drainage class: Well drained
Saturated hydraulic conductivity: High (5 to 15 mm/sec)
Flooding: Southplatte soils are typically not subject to flooding
Ponding: Southplatte soils are typically not subject to ponding
Use and Vegetation:
Most areas are primarily used for urban development. The potential native vegetation is fourwing saltbush, winterfat, western wheatgrass, and blue grama.
Distribution and Extent: Found on plains, strath terraces, and pediments throughout the City and County of Denver, CO; small extent in north-central Colorado; MLRA 67B.
Soil Survey Region (SSR) Responsible:
Bozeman, Montana
Series Proposed:
Denver County, CO 2025. Southplatte series is the name of the river that flows through the City and County of Denver.
Remarks:
Typical Pedon Taxonomic Features:
Ochric epipedon--0 to 18 centimeters (^A horizon)
Human-transported materials--0 to 18 centimeters (^A horizon)
Lithologic discontinuity: 18 centimeters
Cambic horizon-18 to 33 centimeters (2Bwb horizon)
Identifiable secondary carbonates: 33 to 78 centimeters (2Bkb horizon)
Particle-size control section--25 to 100 centimeters
Taxonomic version: Keys to Soil Taxonomy, 13th edition, (2022)
National Cooperative Soil Survey
U.S.A.