LOCATION MCCONNEL NV+CA OREstablished Series
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 1 inch; 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 pebbles; neutral (pH 7.0); abrupt smooth boundary. (1 to 5 inches thick)
A2--1 to 9 inches; 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 10 inches thick)
Bw--9 to 16 inches; 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 pebbles; slightly alkaline (pH 7.6); clear wavy boundary. (6 to 15 inches thick)
2Bk1--16 to 20 inches; 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 many fine roots; many very fine and fine interstitial pores; secondary carbonates segregated as common coats on the bottoms of pebbles; slightly effervescent; 60 percent pebbles; moderately alkaline (pH 8.0); clear wavy boundary. (4 to 7 inches thick)
3Bk2--20 to 30 inches; 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, many fine, and few medium interstitial pores; secondary carbonates segregated as common coats on pebbles; 75 percent pebbles; violently effervescent; very strongly alkaline (pH 9.2); clear wavy boundary. (4 to 19 inches thick)
4C--30 to 72 inches; 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) pebbles and sand grains; single grain; loose, nonsticky and nonplastic; few fine roots; many very fine, many 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; 41 degrees 37 minutes 42 seconds north latitude and 117 degrees 48 minutes 03 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in winter and spring, dry in summer and fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature - 50 to 54 degrees F.
Depth to base of cambic horizon - 10 to 20 inches.
Depth to identifiable secondary carbonates - 10 to 20 inches.
Particle-size control section - Clay content: Averages 3 to 8 percent; Rock fragments: Averages 35 to 80 percent, mainly pebbles. Lithology of fragments are rocks of mixed but mainly volcanic lithologies 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 inches).
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.
2Bk, 3Bk, and 4C 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: Stratified extremely gravelly coarse sand to very gravelly sandy loam.
Structure: Single grain or massive, subangular or blocky in subhorizons of some pedons.
Consistence: Loose through slightly hard dry, loose through friable moist.
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 (T) 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, and offshore bars. These soils formed in two parent materials; the upper part is alluvium derived from mixed rocks with an component of loess and volcanic ash; the lower part is lacustrine deposits or gravelly alluvium derived from mixed rocks. Slopes are 0 to 50 percent. Elevations range from 4,000 to 6,400 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 7 to 10 inches, the mean annual temperature is 47 to 51 degrees F., 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 PERMEABILITY: Somewhat excessively drained; very low, low, or medium surface runoff; moderately rapid permeability in the upper part over very rapid permeability in the lower part.
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 OFFICE RESPONSIBLE: Reno, Nevada.
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 9 inches (A1 and A2 horizons).
Cambic horizon - The zone from 9 to 16 inches (Bw horizon).
Identifiable secondary carbonates - The zone from 16 to 30 inches (2Bk1 and 3Bk2 horizons).
Particle-size control section - The zone from 10 to 40 inches (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.