LOCATION GRIBBLE OREstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Haplic Durixerolls
TYPIFYING PEDON: Gribble cobbly loam, range. (Colors are for moist soil unless otherwise noted.)
A1--0 to 3 inches; black (10YR 2/1) cobbly loam, dark gray (10YR 4/1) dry; weak thin platy and moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; 10 percent pebbles and 15 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (3 to 6 inches thick)
A2--3 to 10 inches; black (10YR 2/1) cobbly clay loam, very dark gray (10YR 3/1) dry; moderate very fine and fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine and fine roots; many very fine tubular pores; 10 percent pebbles and 20 percent cobbles; neutral (pH 6.6); clear wavy boundary. (4 to 8 inches thick)
Bt--10 to 15 inches; very dark gray (10YR 3/1) very cobbly clay, dark gray (10YR 4/1) dry; strong medium and fine blocky structure; extremely hard, very firm, very sticky and very plastic; common very fine and medium roots; many very fine tubular pores; thick continuous clay films or pressure faces; 30 percent cobbles and 15 percent pebbles; neutral (pH 6.6); clear irregular boundary. (4 to 10 inches thick)
Btss--15 to 27 inches; dark grayish brown (10YR 4/2) very cobbly clay, grayish brown (10YR 5/2) dry; strong medium blocky structure; extremely hard, friable, very sticky and very plastic; common very fine and medium roots; many very fine tubular pores; prominent continuous very dark grayish brown (10YR 3/2) clay films; 30 percent cobbles and 15 percent pebbles; few slickensides that do not intersect; neutral (pH 7.0); clear irregular boundary. (7 to 15 inches thick)
Btkss--27 to 30 inches; dark brown (10YR 4/3) very cobbly silty clay, brown (10YR 5/3) dry; moderate medium subangular blocky structure; extremely hard, friable, moderately sticky and moderately plastic; common fine roots; many very fine tubular pores; prominent continuous clay films or pressure faces; few slickensides; thick lime coatings on lower ped surfaces and under rock fragments; 35 percent cobbles and 20 percent pebbles; slightly effervescent; slightly alkaline (pH 7.8); clear irregular boundary. (0 to 6 inches thick)
Btk--30 to 37 inches; yellowish brown (10YR 5/4) very cobbly clay loam, light yellowish brown (10YR 6/4) dry; massive; very hard, very firm, moderately sticky and moderately plastic; few very fine roots; many very fine tubular pores; prominent clay films in pores; 20 percent pebbles and 40 percent cobbles; mycelial like lime veins and lime deposits on lower sides of fragments; strongly calcareous; moderately alkaline (pH 8.0); clear smooth boundary. (3 to 8 inches thick)
2Bqm--37 to 43 inches; brown (10YR 4/3) silica cemented gravelly and cobbly duripan, very pale brown (10YR 7/3) dry; massive; weakly and strongly cemented, very hard, very firm; about 1/3 of surface of duripan indurated and coated with opal or opal and sesquioxides.
TYPE LOCATION: Jefferson County, Oregon; 100 feet west of BPA power pole number 4 in the NW1/4 NE1/4 SE1/4 section 13, T.13S., R.14E.
RANGE IN CHARACTERISTICS: These soils are usually moist but are dry for 70 to 90 consecutive days between depths of 4 and 12 inches within the 3 month period following the summer solstice. The mean annual soil temperature is 47 to 49 degrees F. Depth to duripan is 20 to 40 inches.
The A horizon has value of 3 through 5 dry and 2 or 3 moist. It is cobbly clay loam, cobbly silty clay loam or cobbly loam. This horizon has weak platy to moderate granular and very fine and fine subangular blocky structure. It has 10 to 25 percent cobbles and 10 to 20 percent gravel.
The Btss and Btkss horizon has value of 4 or 5 dry and 3 or 4 moist, and chroma of 2 or 3. It is very cobbly clay or silty clay with 40 to 60 percent clay and has moderate or strong blocky or subangular blocky structure. It has 20 to 35 percent cobbles and 15 to 25 percent gravel.
The 2Btk horizon has value of 6 or 7 dry and 4 or 5 moist, and chroma of 2 through 4. It has 30 to 40 percent cobbles and 15 to 25 percent pebbles.
The 2Bqm horizon is weakly to strongly cemented, massive or platy, and less than 1/2 of the surface of the duripan is coated with opal or opal and sesquioxides.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: These soils are on gently sloping to moderately steep pediments at elevations of 3,300 to 3,900 feet. Slope gradients range from fine textured sediments mixed with rhyolite and basalt colluvium. The climate is semiarid with cool dry summers and cold moist winters; the mean annual temperature is 45 to 47 degrees F.; the mean summer temperature is 61 to 63 degrees F.; and the mean winter temperature is 30 to 33 degrees F. The mean annual precipitation ranges from 12 to 14 inches. The average frost free period is 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Degner, McMeen, and Tub soils. Degner and Tub soils lack duripans. McMeen soils have cambic horizons with less than 35 percent coarse fragments.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; very slow permeability.
USE AND VEGETATION: Used primarily for range with some cropland. Native vegetation is dominated by Idaho fescue, bluebunch wheatgrass, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Central Oregon; MLRA 10, John Day area. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County (Trout Creek, Shaniko Area), Oregon, 1970.
REMARKS: Diagnostic horizons and other features:
Mollic epipedon - 0 to 10 inches
Argillic horizon - 10 to 37 inches
Duripan - 37 to 43 inches, strongly cemented