LOCATION HIBBARD            OR
Established Series
Rev. GDM/MGL/RWL
02/97

HIBBARD SERIES


The Hibbard series consists of moderately deep to a duripan, well drained soils that formed in mixed alluvium. Hibbard soils are on fan terraces and have slopes of 2 to 12 percent. The mean annual precipitation is about 15 inches, and the mean annual temperature is about 47 degrees F.

TAXONOMIC CLASS: Fine, smectitic, mesic Palexerollic Durixerolls

TYPICAL PEDON: Hibbard gravelly silty clay loam - on a 3 percent convex slope; rangeland. (Colors are for moist soils unless otherwise noted.)

A--0 to 5 inches; very dark gray (10YR 3/1) gravelly silty clay loam, gray (10YR 5/1) dry; moderate fine and medium subangular blocky structure; hard, firm, sticky and plastic; many very fine and fine roots; few very fine and fine continuous vertical tubular pores; 25 percent gravel and 3 percent cobbles; neutral (pH 6,8); clear smooth boundary. (4 to 8 inches thick)

AB--5 to 9 inches; very dark grayish brown (10YR 3/2) gravelly silty clay loam, grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; hard, firm, sticky and plastic; common very fine and fine roots; few very fine tubular pores; 15 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (3 to 7 inches thick)

2Bt1--9 to 19 inches; very dark grayish brown (10YR 3/2) clay, brown (10YR 5/3) dry; strong coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; few very fine and fine roots; few very fine tubular pores; many prominent clay films on face of peds and line pores; 5 percent gravel; mildly alkaline (pH 7.4); clear wavy boundary. (7 to 15 inches thick)

2Bt2--19 to 28 inches; dark brown (10YR 4/3) silty clay, yellowish brown (10YR 5/4) dry; moderate coarse subangular blocky structure; hard, film, sticky and plastic; few very fine roots; few very fine tubular pores; many distinct clay films on faces of peds and line pores; moderately alkaline (pH 8.0); clear smooth boundary. (3 to 14 inches thick)

2BCk--28 to 34 inches; yellowish brown (10YR 5/4) silty clay loam, pale brown (10YR 6/3) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (3 to 9 inches thick)

3Ckqm1--34 to 45 inches; brownish yellow (10YR 6/6) and very pale brown (10YR 8/3) duripan; indurated; laminar capping on surface and in fractures; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (9 to 20 inches thick)

3Ckqm2--45 to 60 inches; yellow (10YR 7/6) duripan; strongly cemented; extremely hard, some indurated bands, violently effervescent; strongly alkaline (pH 8.6)

TYPE LOCATION: Baker County, Oregon; 1,400 feet south and 150 feet east of the NW corner of sec. 25, T. 9 S., R. 42 E.

RANGE IN CHARACTERISTICS: The soils are dry in all parts between about 4 to 12 inches for 60 to 90 consecutive days after the summer solstice. The mean annual soil temperature is 47 to 51 degrees F. Depth to the duripan is 20 to 40 inches. Depth to bedrock is over 60 inches. There is an absolute increase in clay of 15 percent or more within one inch between the A and B horizons.

The A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 1 or 2 moist and dry. It is silt loam and gravelly silty clay loam and contains 20 to 35 percent clay. It has 0 to 25 percent gravel and 0 to 5 percent cobbles.

The 2Bt horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 2 through 4 moist and dry. It is clay or silty clay and contains 45 to 60 percent clay. It has 0 to 10 percent gravel and 0 to 5 percent cobbles.

The 2BCk horizon has value of 4 through 6 moist and dry and chroma of 3 or 4 moist and dry. It silty clay loam or clay loam. It is weakly to violently effervescent.

The 3Ckqm horizon is indurated throughout or indurated in the upper few inches and weak to strongly cemented below. It is massive or platy.

COMPETING SERIES: There are no series in the series in the same family. The similar Salisbury series do not have an abrupt textural change.

GEOGRAPHIC SETTING: Hibbard soils are on fan terraces at elevations of 3,000 to 3,700 feet. Slopes are 2 to 12 percent. The soils formed in mixed alluvium. The climate is characterized by cold wet winters and hot dry summers. The mean annual precipitation is 12 to 16 inches. The mean annual temperature is 45 to 50 degrees F, mean summer , temperature is 60 to 70 degrees F, and mean winter temperature is 24 to 28 degrees F. The frost-free period is 110 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Durkee, Gwinly, Immig, Pritchard and Virtue soils. Durkee soils are frigid, lack a duripan and are located on the adjacent uplands. Gwinly and Immig soils are clayey-skeletal, lack a duripan and are located on adjacent uplands. Pritchard soils are deep and are located on adjacent uplands. Virtue soils are fine-silty, have ochric epipedons and are located on adjacent lower terraces.

DRAINAGE AND PERMEABILITY: Well drained; runoff is slow; slow permeability.

USE AND VEGETATION: These soils are used for rangeland. The native vegetation is bluebunch wheatgrass, Idaho fescue and big sagebrush.

DISTRIBUTION AND EXTENT: Eastern Oregon. The soils of this series are not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Baker County Area, Oregon, 1942.

REMARKS: This draft represents a reclassification from fine, montmorillonitic, mesic Typic Durixerolls to fine, montmorillonitic, mesic Abruptic Durixerolls based on the addition of the Abruptic subgroup to soil taxonomy.

Diagnostic horizons and features in this pedon are:

Mollic epipedon - the zone from the surface of the soil to a depth of approximately 19 inches (A, AB, 2Bt1 horizons).

Argillic horizon - the zone from approximately 9 to 28 inches (2Bt1, 2Bt2 horizons). There is an absolute difference in percent clay of 15 percent or more between the AB and 2Bt1 horizons (Abruptic).

This soil is on the Dolph geomorphic surface.

NSTH 17, RECLASSIFICATION ONLY, 3/95


National Cooperative Soil Survey
U.S.A.