LOCATION SECONDSET               CO

Established Series
Rev. WPT-JPP-KLS
05/2023

SECONDSET SERIES

The Secondset series consist of moderately deep, well drained moderately permeable soils that formed in mixed materials from eolian deposits, limestone, sandstone, basalt, and quartzite. These soils are on high plateaus or mesa tops and flat mountain tops and have slopes of 0 to 35 percent. The mean annual precipitation is about 810 mm, and the mean annual temperature is about 2 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive Pachic Haplocryolls

TYPICAL PEDON: Secondset loam - open spruce and fir woodland (colors are for dry soil unless otherwise noted).

Oi--0 to 5 cm; partially decomposed forest litter.

A--5 to 20 cm; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure, parting to moderate fine granular; slightly hard, very friable, slightly sticky, slightly plastic; 5 percent gravel and few scattered cobbles; moderately acid; clear smooth boundary. (13 to 20 cm thick)

Bw--20 to 50 cm; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; 5 percent gravel and few scattered cobbles; moderately acid; clear smooth boundary. (25 to 46 cm thick)

BC--50 to 70 cm; yellowish brown (10YR 5/4) loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; 10 percent gravel, 5 percent cobbles; slightly acid; clear wavy boundary. (15 to 25 cm thick)

C--70 to 88 cm; yellowish brown (10YR 5/4) gravelly loam, brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky, slightly plastic; 15 percent gravel, 10 percent cobbles; slightly acid; abrupt wavy boundary. (10 to 20 cm thick)

R--88 cm; hard bedrock.

TYPE LOCATION: Garfield County, Colorado; about 550 meters west and 715 meters north of the projected southeast corner of sec. 26, T. 4 S., R. 90 W. (Area is not sectionized). U.S.G.S. Adams Lake quad.; lat. 39 degrees, 40 minutes, 22 seconds N., and long. 107 degrees, 27 minutes, 20 seconds W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--3 to 7 degrees C
Mean summer soil temperature--7 to 10 degrees C
Moisture control section--moist in some or all parts in the period between the winter and summer solstice when the soil is not frozen and is moist in some parts of the moisture control section following the summer solstice for 60 to 90 cumulative days.
Mollic epipedon thickness (pachic feature)--40 to 90 cm
Depth to lithic contact--50 to 100 cm
The O horizon is not present in some pedons.

Particle-size control section:
Texture--loam, clay loam or sandy clay loam
Clay content--18 to 30 percent
Rock fragment content--0 to 30 percent; dominantly gravel size
Reaction--pH 5.6 to 7.3

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

Bw horizon
Hue--2.5Y through 7.5YR
Value--4 or 5, 2 or 3 moist
Chroma--2 or 3
Texture--loam, clay loam or sandy clay loam

BC and C horizons
Hue--2.5Y through 7.5YR
Value--4 through 6, 3 through 5 moist
Chroma--3 or 4
Texture--loam, clay loam or sandy clay loam

COMPETING SERIES: These are the Adel (CO), Bullbasin (CO), Bullrey (ID), Duff (NV), Gallatin (MT), Hackwood (NV), Idmon (ID), Karlan (ID), Lamphier (CO), Leavittville (WY), Lespate (CO), Mundos (WY), Osmund (WY), Pavohroo (ID), Rhone (CO), Strickland (NV), Taterheap (CO), and Winevada (CO) series. Adel, Bullbasin, Bullrey, Duff, Gallatin, Lamphier, Leavittville, Mundos, Osmund, Pavohroo, and Rhone soils lack bedrock above depths of 100 cm. Karlan and Lespate soils have consistent k horizons. Winevada soils have moisture control sections that are dry for longer cumulative periods following the summer solstice. Hackwood and Taterheap soils are very deep. Idmon soils lack bedrock above a depth of 100 cm. Strickland soils have evidence of clay movement.

GEOGRAPHIC SETTING:
Landform--side slopes of low hills, ridges and knobs on plateaus and flat mountain tops
Elevation--2625 to 3500 meters
Slope--0 to 35 percent
Parent material--mixed materials from limestone, sandstone, basalt, and quartzite
Mean annual precipitation--640 to 890 mm; most of which comes as snow
Mean annual air temperature--1 to 6 degrees C
Frost-free period--45 to 60 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.

USE AND VEGETATION: Secondset soils are used for timber production, limited late summer grazing, wildlife habitat and for recreation. Native vegetation includes stands of spruce and fir forest with subalpine grasses in the understory.

DISTRIBUTION AND EXTENT: Secondset soils are moderately extensive in the mountainous areas of northwestern Colorado and northeastern Utah; MLRA 48A.

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

SERIES ESTABLISHED: Garfield County (Flat Tops Soil Survey Area in the Flat Tops Wilderness Area), Colorado, 1984.

REMARKS: Diagnostic features include:
Mollic epipedon--5 to 50 cm (A and Bw horizons)
Cambic horizon--20 to 50 cm (Bw horizon)
Lithic contact--88 cm to hard bedrock (R horizon)

Converted to metric and O horizons were updated to start at zero. Competing series section was not updated. 05/2023

---

National Cooperative Soil Survey
U.S.A.