LOCATION MILLENIUM               OR

Established Series
Rev. CWL-MPK-JVC-JBF
04/2011

MILLENIUM SERIES

The Millenium series consists of very deep, well drained soils that formed in eolian materials and lacustrine deposits derived from volcanic ash. Millenium soils are on lakebeds. Slopes are 0 to 2 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Ashy, glassy, frigid Vitritorrandic Argixerolls

TYPICAL PEDON: Millenium ashy fine sandy loam--on a nearly level lakebed at an elevation of 1,392 meters--rangeland. (Colors are for dry soil unless otherwise noted. When described on August 16, 2001 the soil was dry throughout.)

A1--0 to 8 cm; grayish brown (10YR 5/2) ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate thick platy structure parting to weak fine granular; soft, very friable, slightly sticky and nonplastic; many very fine, common fine and few medium roots; common very fine, common fine, and few medium interstitial and tubular pores; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 10 cm thick)

A2--8 to 23 cm; grayish brown (10YR 5/2) ashy fine sandy loam, dark brown (10YR 3/3) moist; weak thick platy structure parting to moderate coarse subangular blocky; soft, very friable, slightly sticky and slightly plastic; common very fine, common fine, and few medium roots; common very fine, common fine, and few medium interstitial and tubular pores; slightly alkaline (pH 7.5); abrupt smooth boundary. (15 to 20 cm thick)

Bt1--23 to 36 cm; brown (10YR 5/3) ashy sandy clay loam, brown (10YR 4/3) moist; weak medium platy structure parting to moderate medium subangular blocky; hard, friable, slightly sticky and slightly plastic; few very fine, few fine, and few medium roots; few very fine, few fine, and few medium tubular pores; common faint clay films on faces of peds and lining pores; slightly alkaline (pH 7.5); clear smooth boundary. (13 to 18 cm thick)

Bt2--36 to 56 cm; 50 percent light yellowish brown (10YR 6/4) and 50 percent light brownish gray (10YR 6/2) ashy sandy clay loam, brown (10YR 4/3) and dark grayish brown (10YR 4/2) moist; moderate medium prismatic structure parting to strong coarse angular blocky; hard, friable, moderately sticky and moderately plastic; few very fine and few fine roots; few very fine and few fine tubular pores; common distinct and few prominent dark brown (7.5YR 3/3) clay films on faces of peds and lining pores; slightly alkaline (pH 7.6); clear wavy boundary. (15 to 23 cm thick)

Btq--56 to 76 cm; pale brown (10YR 6/3) ashy sandy loam, dark grayish brown (10YR 4/2) moist; moderate thick platy structure parting to moderate medium subangular blocky; hard, friable, slightly sticky and slightly plastic; few very fine and few fine roots; few very fine and few fine tubular pores; few distinct clay films on faces of peds; few thin strata of silty clay loam; common distinct secondary silica coats on faces of peds; slightly alkaline (pH 7.6); clear wavy boundary. (15 to 23 cm thick)

BCq--76 to 97 cm; pale brown (10YR 6/3) stratified ashy silty clay loam to ashy loamy sand, brown (10YR 4/3) and dark grayish brown (10YR 4/2) moist; moderate thick platy structure parting to moderate medium angular blocky; hard, firm, moderately sticky and moderately plastic; few very fine and few fine roots; few very fine and few fine tubular pores; few distinct opaline silica coats on faces of peds; slightly alkaline (pH 7.6); abrupt wavy boundary. (13 to 23 cm thick)

C1--97 to 119 cm; pale brown (10YR 6/3) ashy silty clay loam, brown (10YR 4/3) moist; moderate medium platy structure parting to strong fine angular blocky; hard, firm, moderately sticky and moderately plastic; few very fine and few fine roots; few very fine, few fine, and few medium tubular pores; many fine and many medium distinct strong brown (7.5YR 4/6) moist, relict masses of iron accumulation; slightly alkaline (pH 7.6); abrupt smooth boundary. (20 to 28 cm thick)

2C2--119 to 165 cm; light brownish gray (2.5Y 6/2) ashy loamy fine sand, olive brown (2.5Y 4/3) moist; moderate thick platy structure parting to weak coarse subangular blocky; slightly hard, very friable, nonsticky and nonplastic; few very fine through medium tubular pores; one two inch stratum of ashy sand at top of horizon; common fine and medium distinct strong brown (7.5YR 4/6) moist, relict masses of iron accumulation; slightly alkaline (pH 7.8).

TYPE LOCATION: Lake County, Oregon; east of Stauffer Rim and about 3,000 feet northeast of Stauffer Well; approximately 2,700 feet south and 50 feet west of the northeast corner of section 10, T. 24 S., R. 21 E.; USGS Potato Lake 7.5 minute topographic quadrangle; latitude 43 degrees 30 minutes 25 seconds N and longitude 120 degrees 10 minutes 34 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the moisture control section in winter and spring, dry in summer and fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 20 to 25 cm.
Depth to base of argillic horizon: 60 to 90 cm.
Volcanic glass content: 35 to 95 percent in coarse silt through fine sand fractions.

Particle-size control section - Clay content: Averages 18 to 27 percent.

A1 horizon
Organic matter content: 1 to 3 percent.

A2 horison
Clay content: 5 to 15 percent.
Organic matter content: 1 to 3 percent.

Bt horizons
Value: 4 through 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Ashy sandy clay loam or ashy clay loam.
Clay content: 25 to 35 percent.

Btq horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 15 to 20 percent.

BCq and C horizons
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Texture: Stratified ashy loamy sand to ashy silty clay loam.
Clay content: 5 to 40 percent, averaging 10 to 30 percent.

2C horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Texture: Ashy loamy fine sand, ashy loamy sand, or ashy sandy loam.
Clay content: 5 to 15 percent.
Other features: Redoximorphic features are present in some pedons as masses of iron accumulation which are relict redox concentrations.

COMPETING SERIES: These are the Ashdos, Ashtre, Lastcall, and Stauffer series.

Ashdos and Ashtre soils are moderately deep to paralithic contacts. Lastcall soils are moderately deep to lithic contacts. Stauffer soils have horizons with up to 45 percent durinodes.

GEOGRAPHIC SETTING: Millenium soils are on lakebeds. These soils formed in eolian materials and lacustrine deposits derived from volcanic ash. Slopes are 0 to 2 percent. Elevations range from 1,332 to 1,525 meters. The climate is semiarid and characterized by cold, moist winters and warm, dry summers. The mean annual precipitation is 230 to 300 mm, the mean annual temperature is 6 to 7 degrees C, and the frost-free period is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Stauffer soil and the Borobey, Raztack, and Senra soils. Borobey soils do not have argillic horizons, average 8 to 15 percent clay in the particle-size control section, and have noncemented horizons which are firm and brittle. Raztack soils are fine, deep to duripans, and have ochric epipedons. Senra soils are shallow to duripans.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; low or negligible surface runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Millenium soils are used for livestock grazing and wildlife habitat. The vegetation is mainly basin big sagebrush, Idaho fescue, needleandthread, Thurber's needlegrass, and gray rabbitbrush.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 1,700 acres of the series mapped to date. MLRA 23.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Lake County (Northern Part), Oregon, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 230 cm (A1 and A2 horizons).
Argillic horizon - The zone from 23 to 76 cm (Bt1, Bt2, and Btq horizons).
Vitrandic intergrade feature - The zone from the soil surface to 76 cm (A1, A2, Bt1, Bt2, and Btq horizons).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 23 to 73 cm (Bt1 and Bt2 horizons and part of the Btq horizon).

---

National Cooperative Soil Survey
U.S.A.