LOCATION NARRAGUINNEP CO

Established Series
Rev. WSH/CRP/JCK
03/2017

NARRAGUINNEP SERIES

The Narraguinnep series consists of very deep, well drained soils that formed in alluvium, colluvium or slide deposits derived from shale. These soils are on alluvial fans, fan remnants, mountain slopes, landslides, drainageways and swales. Slopes are 0 to 60 percent. Mean annual precipitation is about 584 mm, and mean annual air temperature is about 5.5 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Pachic Vertic Haplustolls

TYPICAL PEDON: Narraguinnep silty clay loam, on a southeast facing 20 percent slope in rangeland, at an elevation of 2,480 meters (colors are for dry soil unless otherwise noted).

A1--0 to 18 cm; dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; neutral (pH 7.2); clear smooth boundary. (8 to 30 cm thick)

A2--18 to 46 cm; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; very hard, very firm, moderately sticky and moderately plastic; neutral (pH 7.2); clear smooth boundary. (23 to 30 cm thick)

Bw--46 to 58 cm; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; extremely hard, extremely firm, moderately sticky and moderately plastic; strongly effervescent; slightly alkaline (pH 7.6); clear wavy boundary. (13 to 38 cm thick)

Bk--58 to 76 cm; light brownish gray (10YR 6/2) clay, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; extremely hard, extremely firm, moderately sticky and moderately plastic; few fine threadlike carbonate masses and finely disseminated carbonates; violently effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (13 to 25 cm thick)

BCk--76 to 150 cm; light gray (2.5Y 7/2) paragravelly silty clay loam, grayish brown (2.5Y 5/2) moist; massive; extremely hard, extremely firm, moderately sticky and moderately plastic; few fine threadlike carbonate masses and finely disseminated carbonates; 25 percent paragravel; violently effervescent; moderately alkaline (pH 8.0).

TYPE LOCATION: Dolores County, Colorado; about 27 kilometers north of Dolores, Colorado; located about 152 meters south and 305 meters east of the northwest corner of Sec. 27, T. 40 N., R. 14 W.; Willow Springs USGS quad; lat. 37 degrees 42 minutes 14 seconds N. and long. 108 degrees 23 minutes 14 seconds W., NAD 27

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C
Mean summer soil temperature - 16 to 19 degrees C
Mollic epipedon thickness - 40 to 60 cm

A horizons
Hue: 10YR or 2.5Y
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3, dry or moist
Texture: silty clay loam, clay loam or clay
Clay content: 28 to 50 percent
Rock fragments: 0 to 15 percent paragravel
Reaction: 7.0 to 7.8

Bw horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 1 to 3, dry or moist
Texture: clay or clay loam
Clay content: 35 to 50 percent
Rock fragments: 0 to 15 percent paragravel
Reaction: 7.2 to 8.0

Bk horizon
Hue: 10YR to 2.5Y
Value: 5 to 7 dry, 3 to 5 moist
Chroma: 2 to 4, dry or moist
Texture: clay or clay loam
Clay content: 35 to 50 percent
Rock fragments: 0 to 15 percent paragravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: 7.8 to 8.4

BCk horizon
Hue: 10YR to 5Y
Value: 5 to 7 dry, 3 to 5 moist
Chroma: 2 to 4, dry and moist
Texture: silty clay loam, clay loam or clay
Clay content: 28 to 50 percent
Rock fragments: 0 to 25 percent paragravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: 7.8 to 8.2

COMPETING SERIES:
Magnus (ND) - do not have horizons of secondary calcium carbonate accumulation; have buried surface horizons

GEOGRAPHIC SETTING:
Parent material: alluvium, colluvium or slide deposits
Landform: alluvial fans, fan remnants, mountain slopes, landslides, drainageways and swales
Slopes: 0 to 60 percent
Elevation: 2,200 to 2,900 meters
Mean annual air temperature: 4.0 to 6.0 degrees C.
Mean annual precipitation: 455 to 635 mm
Frost-free period: 70 to 100 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bradfield, Coulterg, Dapoin, Pagoda and Gladlow series.

DRAINAGE AND PERMEABILITY: Well drained; moderately slow to slow permeability.

USE AND VEGETATION: Narraguinnep soils are used for livestock grazing and wildlife habitat. Principal native vegetation is western wheatgrass, Letterman's needlegrass, mountain big sagebrush, Saskatoon serviceberry, muttongrass, slender wheatgrass, Gambel oak, and Arizona fescue.

DISTRIBUTION AND EXTENT: Narraguinnep soils are of moderate extent in southwestern Colorado. MLRA 36, 48A.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: San Miguel Area, Colorado, Parts of Dolores, Montrose, and San Miguel Counties, 1987.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 46 cm (A1 and A2 horizons)
Secondary calcium carbonate accumulation - from 58 to 150 cm (Bk and BCk horizons)
Particle-size control section - from 25 to 100 cm (part of the A2, Bw, Bk, and part of the BCk horizon)

Narraguinnep soils have a frigid temperature regime and an ustic moisture regime.

This description reflects an update in classification from Keys to Soil Taxonomy Eighth Edition, 1998 to Keys to Soil Taxonomy Twelfth Edition, 2014. Classification is updated from Fine, smectitic, frigid Vertic Haplustolls to Fine, smectitic, frigid Pachic Vertic Haplustolls.

ADDITIONAL DATA: Kellogg Soil Survey Laboratory - lab pedon number 86P0857.

National Cooperative Soil Survey
U.S.A.