LOCATION LEMONEX                 OR

Established Series
Rev. ED/AON/TDT
03/2013

LEMONEX SERIES

The Lemonex series consists of moderately deep, well drained soils that formed in colluvium and residuum weathered mainly from serpentine or ultamafic bedrock with a surface influence of Mazama volcanic ash. Lemonex soils are on hills and mountains having slopes of 3 to 50 percent. The mean annual precipitation is about 48 centimeters (19 inches), and the mean annual air temperature is about 6 degrees C. (43 degrees F.).

TAXONOMIC CLASS: Fine, magnesic, frigid Vitrandic Argixerolls

TYPICAL PEDON: Lemonex stony ashy clay loam - woodland, on a 16 percent slope at an elevation of 1322 meters (4,340 feet). (When described on October 23, 1974, the soil was dry throughout. Colors are for moist soil unless otherwise noted.)

Oi--0 to 3 centimeters (0 to 1 inch); pine needles, twigs and leaves; abrupt smooth boundary. (1 to 3 inches thick)

A1--3 to 8 centimetyers (1 to 3 inches); black (10YR 2/1) stony ashy clay loam, dark gray (10YR 4/1) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common fine discontinuous pores; 10 percent stones, 5 percent cobbles and 10 percent gravel; neutral (pH 6.6); clear smooth boundary. (5 to 25 centimeters (2 to 10 inches) thick)

A2--8 to 23 centimeters (3 to 9 inches); black (10YR 2/1) ashy clay loam, dark gray (10YR 4/1) dry; moderate fine subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; many very fine, common medium and few coarse roots; common fine discontinuous pores; neutral (pH 6.8); clear smooth boundary. (0 to 25 centimeters (0 to 10 inches) thick)

Bt1--23 to 36 centimeters (9 to 14 inches); very dark grayish brown (10YR 3/2) gravelly clay, dark gray (10YR 4/1) dry; moderate medium subangular blocky parting to moderate very fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common fine and few coarse roots; common fine continuous pores; many distinct clay films on ped faces; 20 percent serpentine gravel; neutral (pH 6.8); clear smooth boundary.

Bt2--36 to 71 centimeters (14 to 28 inches); olive (5Y 4/4) gravelly clay, pale olive (5Y 6/3) dry; moderate medium subangular blocky structure; extremely hard, firm, moderately sticky and very plastic; common fine and few coarse roots; common very fine continuous tubular pores; common distinct clay films on ped faces; 30 percent serpentine gravel; neutral (pH 7.0); abrupt smooth boundary. (Combined thickness of the Bt horizon is 30 to 50 centimeters (12 to 20 inches) thick.)

R--71 centimeters (28 inches); hard fractured serpentine, partially weathered in the upper few inches.

TYPE LOCATION: Grant County, Oregon; about 8 kilometers (5 miles) south and 2.4 kilometers (1 1/2 miles) east of Mt. Vernon; 235 meters (770 feet) south of road junction of Ingle Creek and Laycock Creek roads; NE1/4 SW1/4 section 23, T. 14 S., R. 30 E. Latitude 44 degrees, 20 minutes, 19 seconds North and Longitude 119 degrees, 05 minutes, 00 seconds West.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 42 to 47 degrees F. The soils are usually moist but are dry between depths of 4 and 12 inches for 60 to 80 consecutive days during the four-month period following the summer solstice. Depth to a lithic contact is 50 to 100 centimeters (20 to 40 inches). Rock fragments in the upper 50 centimeters (20 inches) of the Bt horizon range from 15 to 35 percent by volume. The thickness of the mollic epipedon is 25 to 50 centimeters) 10 to 20 inches. Hue is typically 10YR but ranges from 5YR to 5Y. Base saturation by sum is 80 to 95 percent throughout the solum.

The A horizon has chroma of 1 or 2 moist and dry. It has 27 to 35 percent clay, 0 to 40 percent stones, 0 to 5 percent cobbles and 0 to 10 percent gravel. Volcanic glass ranges from 5 to 20 percent and oxalate extracted Al and one-half iron ranges from 0.2 to 0.5 percent.

The B horizon has value of 3 or 4 dry and chroma of 2 or 3 in the upper part and value of 3 or 4 moist, 4 or 5 dry and chroma of 2 or 3 in the lower part. It has 40 to 60 percent clay, 0 to 15 percent cobbles and 15 to 35 percent gravel.

The R horizon varies considerably in color even within a short distance. The highly fractured serpentine or ultramafic rocks have colors that include greenish black (10GY 2.5/1), dark greenish gray (5GY 4/1), or White (N 8/) with the shiny coating on the fracture layers characteristic of serpentine.

COMPETING SERIES: This is the Wymer soil. The Wymer soil lacks an O horizon and occurs in the range ecotone adjacent to forested areas on north-facing side slopes of hills or sloping benches.

GEOGRAPHIC SETTING: Lemonex soils are on footslopes and side slopes of hills and mountains at elevations of 1036 to 1676 meters (3,400 to 5,500 feet) and on south slopes up to 2012 meters (6,600 feet). They formed in mixed colluvium and residuum weathered mostly from serpentine or ultramafic bedrock with a surface influence of Mazama Volcanic ash. The climate is characterized by cold, wet winters and hot, dry summers. The mean annual precipitation of 41 to 61 centimeters (16 to 24 inches). Mean annual temperature is 4 to 7 degrees C. (40 to 45 degrees F.), mean July temperature is about 13 to 16 degrees C. (56 to 60 degrees F.), and mean January temperature is -3 to -1 degrees C. (27 to 30 degrees F.). The frost-free period is 30 to 75 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Grell, Hankins, Klicker, Overholt (T), Stussi (T), Widows (T), and the competing Wymer (T) soils. Grell, Overholt, Stussi, and Widows soils are formed over serpentine or ultramafic bedrock whereas Hankins and Klicker soils are formed over basalt. Hankins soils are over 40 inches deep. Klicker soils are loamy-skeletal. Both are found on adjacent side slopes. Grell and Stussi soils are in range areas on lower hill slopes, are mesic, are loamy-skeletal, and lack an argillic horizon. Grell soils are lithic. Overholt soils are shallow to serpentine, are on shoulders and ridgetops adjacent to exposed serpentine, are loamy-skeletal, and lack an argillic horizon. Widows soils are shallow to serpentine, are on shoulders and ridgetops adjacent to exposed serpentine, and are clayey-skeletal.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.

USE AND VEGETATION: Timber production and livestock grazing. Native vegetation on north slopes is mainly ponderosa pine and Douglas-fir with an understory of elksedge, pinegrass and Idaho fescue; on south slopes the vegetation is ponderosa pine, western juniper and pinegrass.

DISTRIBUTION AND EXTENT: Mainly in the Strawberry and Aldrich Range of the Blue Mountains of east-central Oregon; MLRA 10. The series is of moderate extent.

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

SERIES ESTABLISHED: Grant County, Oregon, 1975.

REMARKS: Diagnostic horizons and other features:

Vitrandic feature - 3 to 23 centimeters (1 to 9 inches)
Mollic epipedon - 3 to 36 centimeters (1 to 14 inches)
Argillic horizon - 23 to 71 centimeters (9 to 28 inches)
Base saturation - 90 percent by sum based on reference sample S97OR-23-023.
PSCS - 23 to 71 centimeters (9 to 28 inches) (Bt1 and Bt2 horizons)

Xeric moisture regime

ADDITIONAL DATA: Partial lab data is available for this soil. Reference sample S97OR-023-023 from Grant County, OR and were sent to the NSSL in Lincoln, NE. (sampled on August 26, 1997). Classification changed from Typic to Vitrandic based on lab data.

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National Cooperative Soil Survey
U.S.A.