LOCATION DREWSGAP OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Durixerolls
TYPICAL PEDON: Drewsgap loam, cropland. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; very dark brown (10YR 2/2) loam, dark gray (10YR 4/1) dry; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; many very fine pores; slightly acid (pH 6.5); abrupt smooth boundary. (6 to 10 inches thick)
A--8 to 14 inches; very dark grayish brown (10YR 3/2) loam, dark grayish brown (10YR 4/2) dry; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; few very fine tubular pores; slightly acid (pH 6.5); clear smooth boundary. (4 to 10 inches thick)
Bt--14 to 30 inches; dark brown (10YR 3/3) sandy clay loam, grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; hard, firm, sticky and plastic; common very fine roots; few very fine tubular pores; common faint clay films on ped faces and in pores; slightly acid (pH 6.5); clear smooth boundary. (12 to 18 inches thick)
C--30 to 34 inches; dark grayish brown (2.5Y 4/2) sandy loam, massive; slightly hard, very friable, nonsticky and nonplastic; common roots; many very fine pores; slightly acid (pH 6.5); abrupt smooth boundary. (0 to 6 inches thick)
2Cqm--34 to 49 inches; olive brown (2.5Y 4/3) duripan; massive; extremely hard and very firm; strongly cemented and indurated in upper part; mildly alkaline (pH 7.4); gradual smooth boundary. (10 to 20 inches thick)
2C--49 to 61 inches; strong brown (7.5YR 5/8) and dark brown (7.5YR 4/4) very gravelly loam, light brown (7.5YR 6/4) and pinkish white (7.5YR 8/2) dry; massive; 50 percent gravel, 5 percent cobbles; slightly acid (pH 6.6).
TYPE LOCATION: Lake County, Oregon; NE1/4NW1/4 of Sec. 24, T. 39 S., R. 19 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 48 to 50 degrees F. The soils are usually moist and are dry in all parts between the depths of 4 to 12 inches for 100 to 115 consecutive days following the summer solstice. The soils are moist in winter. The mollic epipedon is 10 to 20 inches thick. Depth to the duripan is 20 to 40 inches and depth to bedrock is greater than 60 inches.
The Ap and A horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 1 or 2 moist or dry. It is loam and has 0 to 20 percent gravel.
The Bt horizons have hue of 10YR or 7.5YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 to 4 dry and moist. It is sandy clay loam or clay loam with 25 to 35 percent clay. It has 0 to 25 percent gravel.
The 2Cqm horizon is indurated with 1 to 2 mm thick laminar bands or is strongly cemented and indurated in the upper part. The lower part is weakly cemented in some pedons and contains up to 25 percent gravel. Thin seams of lime-silica occur in some pedons. Some pedons have a 2Bqm horizon.
The 2C horizon has a hue of 10YR, 7.5YR, or 2.5Y, value of 6 to 8 dry, 4 or 5 moist, chroma 2 to 8 moist or dry. It is very gravelly loam or very gravelly sandy loam and contains 25 to 55 percent gravel and 0 to 10 percent cobbles.
COMPETING SERIES: This is the Sweagert(T)(CA) series. Sweagert soils are similar and need further review for series separation.
GEOGRAPHIC SETTING: Drewsgap soils are on lake terraces. Elevations range from 4,800 to 5,200 feet and slopes range from 0 to 15 percent. These soils formed in lacustrine deposits and alluvium of Pleistocene age derived from basalt, andesite, and some pyroclastic rocks. The climate is characterized by cool wet winters and hot dry summers. The mean annual temperature is 45 to 48 degrees. The mean annual precipitation is 14 to 18 inches. The frost-free period is 70 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Deter, Drews, Lakeview, Oxwall, and Salisbury soils. Deter soils lack a duripan and are in the fine family. Drews soils lack a duripan. Lakeview soils are moderately well drained and lack an argillic horizon and a duripan. The Oxwall soils are shallow to a duripan and are in the fine family. Salisbury soils are in the fine family.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability.
DISTRIBUTION AND EXTENT: Basin areas of southeastern Oregon, MLRA 21. The series is inextensive.
USE AND VEGETATION: Drewsgap soils are used for cropland, livestock grazing, and wildlife habitat. Potential vegetation consists of mountain big sagebrush, antelope bitterbrush, bluebunch wheatgrass, and Idaho fescue.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, Oregon, Southern Part, 1991.
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.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 14 inches (Ap and A horizons).
Argillic horizon - 14 to 30 inches (Bt horizon).
Duripan (indurated) - at 34 inches.
ADDITIONAL DATA: Drews series characterization sample, S79OR-037-002 used for reference.
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.