LOCATION PANDO                   CO

Established Series
Rev. GB/KLS
11/2022

PANDO SERIES

The soils of the Pando series are deep, well-drained soils formed in alluvium or glacial outwash derived from a variety of crystalline rock but mainly gneiss and schist. They occur on alluvial fans and high terraces and slopes are 0 to 10 percent. The mean annual precipitation is about 460 mm and the mean annual air temperature is about 2 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Alfic Argicryolls

TYPICAL PEDON: Pando gravelly loamy sand, grassland. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 5 cm; undecomposed and partially decomposed organic material consisting mainly of grass roots and leaves. (3 to 5 cm thick)

A--5 to 35 cm; dark grayish brown (10YR 4/2) gravelly loamy sand, very dark grayish brown (10YR 3/2) when moist; moderate, fine, granular structure; soft, very friable; 30 percent gravel; moderately acid; clear, smooth boundary. (18 to 36 cm thick)

E--35 to 50 cm; pale brown (10YR 6/3) very gravelly loamy sand, brown (10YR 5/3) when moist; weak, thin, platy structure that parts to single grains; soft, very friable, vesicular; 40 percent gravel; moderately acid; clear, smooth boundary. (10 to 25 cm thick)

Bt--50 to 80 cm; yellowish brown (10YR 5/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) when moist; weak to moderate, fine, subangular blocky structure; slightly hard, very friable; thin nearly continuous clay films on peds, on some pebbles, as fillings in root channels and pores, and as bridges between sand grains; 60 percent gravel; slightly acid; gradual, wavy boundary. (23 to 41 cm thick)

2C--80 to 156 cm, light yellowish brown (10YR 6/4) very gravelly loamy sand, yellowish brown (10YR 5/4) when moist; single grained; loose; 80 percent gravel and some cobbles; neutral.

TYPE LOCATION: Chaffee County, Colorado; about 305 meters east of the southwest corner of Sec. 8, T. 15 S., R. 78 W.

RANGE IN CHARACTERISTICS:
Mollic epipedon thickness--18 to 40 cm
Base saturation--60 to 100 percent in all subhorizons of the argillic horizon, and usually is more than 80 percent
Depth to sandy-skeletal 2C horizon--50 to 100 cm
Depth to top of argillic horizon--less than 60 cm
Depth to base of argillic horizon--38 to 100 cm
These soils are noncalcareous to depths of more than 100 cm, and typically, are noncalcareous to depths of more than 150 cm.

Particle-size control section:
Rock fragment content--35 to 80 percent by volume in a major part of the solum and C horizon and are usually less than 75 mm in diameter
Reaction--pH 5.6 to 7.8

A horizon
Hue--2.5Y through 7.5YR
Value--4 or 5 dry, 2 or 3 moist
Chroma--1 through 3

E horizon
Hue--2.5Y through 7.5YR
Value--5 through 8 dry, 4 through 7 moist
Chroma--1 through 4

Bt horizon
Hue--2.5Y through 7.5YR
Value--5 through 7 dry, 4 through 6 moist
Chroma--1 through 6
Texture--gravelly or very gravelly sandy loam
Clay content--8 to 18 percent

2C horizon
Hue of 2.5Y through 7.5YR
Texture--very gravelly sand or very gravelly loamy sand

COMPETING SERIES: These are the Paintrock and Sunshine series. Paintrock soils have medium to moderately fine textured argillic horizons and overlie bedrock at depths of 50 to 100 cm. Sunshine soils have fine textured argillic horizons and overlie fragmental substratums at depths of 50 to 100 cm.

GEOGRAPHIC SETTING:
Landform--alluvial fans and high terraces
Elevation--2425 to 2675 meters
Slope--0 to 10 percent
Parent material--alluvium or glacial outwash derived from a variety of crystalline rock but mainly gneiss and schist
Mean annual precipitation--460 mm, with peak periods of precipitation in the spring and summer
Mean annual air temperature--2 degrees C
Mean summer temperature--11 degrees C
Frost-free period--50 to 75 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability

USE AND VEGETATION: These soils are used as native pastureland, for forestry, and for recreation. Native vegetation is mainly ponderosa pine, with an understory of Arizona fescue, mountain muhly, wheatgrass, and sagebrush.

DISTRIBUTION AND EXTENT: Pando soils are of small extent in the mountain valleys of central and southwest Colorado; MLRA 48A.

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

SERIES ESTABLISHED: Chaffee County, Colorado, 1974

REMARKS: Converted to metric, updated formatting, and O horizons were updated to start at zero. Competing series section was not updated. 11/2022

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National Cooperative Soil Survey
U.S.A.