LOCATION FALCON                  CO+UT

Established Series
Rev. GB/KS/KLS
09/2022

FALCON SERIES

The Falcon series consists of shallow, well to somewhat excessively drained soils that are formed in materials weathered residually from arkose and similar beds overlying hard sandstone, interbedded sandstone and shale, or conglomerate. They are on upland ridges, hills, mountain sideslopes, mesa tops, and benches. Slopes are 0 to 65 percent. The mean annual precipitation is about 430 mm and the mean annual air temperature is about 5 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, frigid Lithic Haplustolls

TYPICAL PEDON: Falcon sandy loam - open timber. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 3 cm; pine needles and partly decomposed litter and twigs.

A--3 to 21 cm; dark grayish brown (10YR 4/2) sandy loam; very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, 10 percent gravel; neutral; clear smooth boundary. (13 to 30 cm thick)

C--21 to 39 cm; light gray (10YR 7/2) gravelly sandy loam; grayish brown (10YR 5/2) moist; weak medium subangular blocky structure; very hard, very friable; 20 percent fine and very fine angular granite gravel; neutral; abrupt smooth boundary.

R--39 inches; hard arkosic sandstone and conglomerate.

TYPE LOCATION: Douglas County, Colorado; on the east side of Colorado State Highway 83, about 150 meters north and 380 meters east of the southwest corner, Sec. 35, T. 10 S., R. 66 W.; Cherry Valley School USGS quad; Lat. 39 degrees 7 minutes 53 seconds N., Long. 104 degrees 45 minutes 1 second W., NAD 27

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 to 7 degrees C
Mean summer soil temperature--12 to 17 degrees C
Mean winter soil temperature--warmer than 0 degrees C, and the soils are not continually frozen during the winter
Depth to lithic contact--25 to 50 cm

Particle-size control section (weighted average)
Texture--Usually gravelly coarse sandy loam, fine sandy loam, or sandy loam
Clay content--5 to 20 percent
Sand content--50 to 80 percent, with more than 35 percent being fine or coarser sand. A large proportion of the sand fraction is medium, coarse, and very coarse angular sand which has a high percentage of flat bearing surfaces between sand grains.
Rock fragment content--0 to 35 percent, mainly less than 75 mm in diameter but range from 3 to 250 mm in diameter.

A horizon:
Hue--2.5Y to 7.5YR
Value--3 to 5 dry, 2 or 3 moist
Chroma--1 to 4 dry or moist
Base saturation--typically is more than 80 percent but ranges from 60 to 100 percent
Reaction--pH 5.6 to 7.6

C horizon (when present):
Hue--2.5Y to 7.5YR
Value--4 to 7 dry, and 4 or 5 moist
Chroma--2 to 4 dry or moist
Texture--fine sandy loam or sandy loam.
Base saturation--typically is more than 80 percent but ranges from 60 to 100 percent
Reaction-- pH 5.6 to 7.6

COMPETING SERIES: These are the Akhoni (NM), Ansari (CO), Corpening (WY), and Falconry (CO) series. Akhoni soils do not have particle-size control sections dominated by coarse sand and have B horizons. Ansari and Corpening soils are calcareous and have continuous horizons of secondary calcium carbonate accumulation. Falconry soils have less than 35 percent fine sand and coarser.

GEOGRAPHIC SETTING:
Landform--upland ridges, hills, sideslopes or mountain hillslopes, and benches generally at the crests and shoulders of the highest parts of the landscape
Elevation--2250 to 2900 meters
Slope--0 to 65 percent
Parent material--residuum derived from arkose sedimentary beds overlying strata of hard sandstone and conglomerate. In other areas, the soils formed in interbedded sandstone and shale and siltstone.
Mean annual precipitation--410 to 480 mm in Colorado. In Utah, and other areas in Colorado, precipitation ranges from 410 to 640 mm per year
Mean annual air temperature--3 to 7 degrees C

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Well to somewhat excessively drained; medium runoff; rapid to moderately rapid permeability above the bedrock.

USE AND VEGETATION: These soils are used primarily as native pastureland. In some localities they support stands of ponderosa pine of some importance for forestry. Native vegetation is primarily thin stands of ponderosa pine, Gambel oak, mountainmahogany, and grasses.

DISTRIBUTION AND EXTENT: Falcon soils are of moderate extent in the Black Forest areas of east-central Colorado and southwestern Colorado and the southeastern and central part of Utah; MLRAs 47, 48A, 49

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Cherry Creek Soil Conservation District, El Paso and Douglas Counties, Colorado, 1946.

REMARKS: Diagnostic horizons and features in this pedon include:
Mollic epipedon--3 to 21 cm (A horizon)
Lithic contact--39 cm (R horizon)
Particle-size control section--25 to 39 cm (part of the C horizon)

Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 3/2022

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National Cooperative Soil Survey
U.S.A.