LOCATION GROTTE COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, calcareous, frigid Ustic Torriorthents
TYPICAL PEDON: Grotte gravelly loam, rangeland. (Colors are for dry soil unless otherwise noted).
A1--0 to 4 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure parting to weak fine granular; slightly hard, friable, nonsticky and slightly plastic; 30 percent pebble size sandstone fragments; slightly alkaline; clear smooth boundary. (2 to 5 inches thick)
A2--4 to 7 inches; brown (10YR 5/3) gravelly clay loam, dark brown (10YR 3/3) moist; weak medium platy structure parting to weak fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; 30 percent pebble sized sandstone fragments; slightly effervescent; moderately alkaline; gradual wavy boundary. (2 to 4 inches thick)
C1--7 to 24 inches; pale brown (10YR 6/3) very channery clay loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; hard firm, slightly sticky and slightly plastic; 45 percent channers; violently effervescent; moderately alkaline; clear irregular boundary. (16 to 20 inches thick)
C2--24 to 60 inches; light brownish gray (10YR 6/2) very channery clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, firm, sticky and plastic; 45 percent channery; violently effervescent; moderately alkaline.
TYPE LOCATION: Eagle County, Colorado; 500 feet north and 1,500 feet east of the southwest corner of sec. 12, T. 5 S., R. 87 W; Cottonwood Pass USGS quad; lat. 39 degrees 37 minutes 26 seconds N. and long. 107 degrees 06 minutes 28 seconds W., NAD 27.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 37 to 40 degrees F, and mean summer soil temperature is 60 to 65 degrees F. Rock fragments in the particle size-control section range from 35 to 75 percent and are mainly pebbles or channers in size. Clay ranges from 25 to 35 percent in the particle size control section. This soil is usually calcareous throughout but may be leached a few inches from the surface. Hard bedrock is common at depths of 40 to 60 inches or more in some pedons.
The A horizon has hue of 2.5Y or 10YR, value of 4 through 6, 3 or 4 moist and chroma of 2 or 3. This horizon is mildly alkaline or moderately alkaline.
The C horizon has hue of 2.5Y or 10YR, value of 6 or 7, 3 through 5 moist and chroma of 2 or 3.
COMPETING SERIES: These are the Grobutte and Southace series. Grobutte soils have less than 25 percent clay in the particle size control section. Southace soils have hues of 7.5YR or redder.
GEOGRAPHIC SETTING: Grotte soils are on fans and mountain hillslopes. Slopes range from 10 to 65 percent. These soils formed in alluvium and colluvium derived from sandstone. The mean annual precipitation at the type location is about 16 inches but ranges from 14 to 18 inches. Elevations range from 6,000 to 8,000 feet. Mean annual temperature ranges from 35 to 42 degrees F and mean summer temperature is 58 to 63 degrees F. The average frost free period is 80 to 105 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dahlquist and competing Southace soils. The Dahlquist soils have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for rangeland and as wildlife habitat. Native vegetation is Wyoming Big Sagebrush, Utah Juniper, Indian Ricegrass, Blue Bunch Wheatgrass, Bottlebrush, Squirreltail, Prairie Junegrass and Needleandthread.
DISTRIBUTION AND EXTENT: Northwestern parts of Colorado and possibly adjacent parts of Utah and Wyoming. The soils of this series are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Aspen Gypsum Soil Survey Area, Eagle County, Colorado, 1982.
REMARKS:
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.