LOCATION MCCONNEL NV+CA OR

Established Series
Rev. JVC/JBF
09/2019

MCCONNEL SERIES

The McConnel series consists of very deep, somewhat excessively drained soils that formed in alluvium derived from mixed rocks with a component of loess and volcanic ash over lacustrine deposits or alluvium. McConnel soils are on inset fans, fan aprons, beach plains, beach terraces, lake terraces, fan skirts, drainage channels, barrier bars, and offshore bars. Slopes are 0 to 50 percent. The mean annual precipitation is about 200 mm and the mean annual temperature is about 10 degrees C.

TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Xeric Haplocambids

TYPICAL PEDON: McConnel fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 3 cm; gray (10YR 6/1) fine sandy loam, dark gray (10YR 4/1) moist; weak thick platy structure; slightly hard, friable, nonsticky and nonplastic; common fine roots; many fine and medium vesicular pores; 5 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (3 to 13 cm thick)

A2--3 to 23 cm; gray (10YR 6/1) fine sandy loam, dark gray (10YR 4/1) moist; weak fine granular structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; neutral (pH 6.8); clear smooth boundary. (0 to 25 cm thick)

Bw--23 to 41 cm; light brownish gray (10YR 6/2) fine sandy loam, grayish brown (10YR 5/2) moist; weak very fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; 5 percent gravel; slightly alkaline (pH 7.6); clear wavy boundary. (15 to 38 cm thick)

2Bk1--41 to 51 cm; grayish brown (10YR 5/2) extremely gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; secondary carbonates segregated as common coats on the bottoms of rock fragments; slightly effervescent; 60 percent gravel; moderately alkaline (pH 8.0); clear wavy boundary. (10 to 18 cm thick)

3Bk2--51 to 76 cm; grayish brown (10YR 5/2) extremely gravelly coarse sand, dark gray (10YR 4/1) moist; single grain; loose, nonsticky and nonplastic; few fine roots; many very fine, fine, and few medium interstitial pores; secondary carbonates segregated as common coats on gravel; 75 percent gravel; violently effervescent; very strongly alkaline (pH 9.2); clear wavy boundary. (10 to 48 cm thick)

4C--76 to 183 cm; grayish brown (10YR 5/2) coarsely stratified coarse sand and gravel, dark grayish brown (10YR 4/2) moist; many very dark gray (10YR 3/1), white (10YR 8/1) and brown (10YR 4/3) gravel and sand grains; single grain; loose, nonsticky and nonplastic; few fine roots; many very fine, fine and few medium interstitial pores; slightly effervescent; strongly alkaline (pH 9.0).

TYPE LOCATION: Humboldt County, Nevada; in the Quinn River Valley about 4 miles north and 1 mile west of Orovada; about 1,900 feet east and 500 feet north of the southwest corner of section 3, T. 43 N., R. 37 E.; USGS Willow Creek Ranch 7.5 minute topographic quadrangle; latitude 41 degrees 37 minutes 44 seconds N and longitude 117 degrees 48 minutes 8 seconds W; WGS84 Decimal Degrees 41.6288889 latitude, -117.802222 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry in summer and fall; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 10 to 12 degrees C.
Depth to base of cambic horizon: 25 to 50 cm.
Depth to identifiable secondary carbonates: 25 to 50 cm.

Particle-size control section - Clay content: Averages 3 to 8 percent.
Rock fragments: Averages 35 to 80 percent, mainly gravel. Lithology of fragments is rocks of mixed but mainly volcanic lithology such as basalt or tuff.

A horizons
Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 3 or 4 moist (5 dry and 3 moist only in the upper 3 cm).
Chroma: 1 through 3, dry or moist.
Reaction: Neutral through moderately alkaline.

Bw horizon
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 2 through 4, dry or moist (1 if dark sand grains are present).
Texture: Loam, sandy loam, fine sandy loam.
Structure: Very fine to medium granular or subangular blocky or it is massive.
Reaction: Neutral through moderately alkaline.

2BC horizon (when present)
Characteristics similar to 2Bk horizon below but ranges to 30 percent rock fragments.

2Bk horizons
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 6 moist.
Chroma: 2 through 4, dry or moist
Texture: Loamy sand or sandy loam.
Rock fragments: 35 to 80 percent, mostly gravel.
Reaction: Slightly alkaline to very strongly alkaline (up to pH 9.6).
Calcium carbonate equivalent: 0 to 5 percent.

3Bk and C horizons
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 6 moist.
Chroma: 2 through 4, dry or moist (1 if dark sand grains are present).
Texture: Sand or coarse sand.
Rock fragments: 35 to 80 percent, mostly gravel.
Reaction: Slightly alkaline to very strongly alkaline (up to pH 9.6).
Calcium carbonate equivalent: 0 to 5 percent.

COMPETING SERIES: These are the Broncho, Malaga, McNye, McWatt, and Ragnel series.

Broncho soils have calcareous Bw horizons and have more than 5 percent calcium carbonate equivalent in the Bk horizons. Malaga soils do not have Bk horizons with identifiable secondary carbonates. McNye and McWatt soils are deep to lithic contacts. Ragnel soils are intermittently moist for 10 to 20 days cumulative in the summer due to convection storms.

GEOGRAPHIC SETTING: McConnel soils are on inset fans, fan aprons, drainage channels, fan skirts, beach terraces, beach plains, barrier bars, lake terraces and offshore bars. These soils formed in two parent materials; the upper part is alluvium derived from mixed rocks with a component of loess and volcanic ash; the lower part is lacustrine deposits or alluvium derived from mixed rocks. Slopes are 0 to 50 percent. Elevations range from 1,220 to 1,950 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 175 to 250 mm, the mean annual temperature is 7 to 11 degrees C, and the frost-free period is 80 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Davey and Orovada soils. Davey soils are sandy. Orovada soils are coarse-loamy and have horizons with durinodes.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; very low, low, or medium surface runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: McConnel soils are used for rangeland and wildlife habitat. Some areas are used for cropland under pump irrigation. The principal crops are alfalfa, potatoes, and small grains. Some areas are used as a source of gravel and sand. The native vegetation is mainly Wyoming big sagebrush, bottlebrush squirreltail, and annuals.

DISTRIBUTION AND EXTENT: Pleistocene lake basins in northern Nevada, northeastern California, and south-central Oregon. These soils are extensive with about 188,000 acres of the series mapped to date. The series concept and main acreage is in MLRA 24, while other acreage occurs in MLRAs 23 and 28B.

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

SERIES ESTABLISHED: Humboldt County, Nevada, (BLM Sonoma Planning Unit), 1974.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A1 and part of A2 horizons).
Cambic horizon - The zone from 23 to 41 cm (Bw horizon).
Identifiable secondary carbonates - The zone from 41 to 36 cm (2Bk and 3Bk horizons).
Particle-size control section - The zone from 25 to 100 cm (2Bk1 and 3Bk2 horizons and parts of the Bw and 4C horizons).

ADDITIONAL DATA: A pedon of McConnel very near the series type location is sampled for full characterization by the Soil Survey Laboratory (SSL), Lincoln, NE, as soil survey sample number S86NV-013-300 (pedon # 86P0762). High volcanic glass content in the upper horizons in this pedon bears further study about extent and amount of ash content in the series in Humboldt County, NV.

Previous authors and editors include: SES-TM-RLB.

National Cooperative Soil Survey
U.S.A.