LOCATION GOPHERIDGE              CA

Established Series
SMM/CES/TKK/JW
12/2018

GOPHERIDGE SERIES

The Gopheridge series consists of moderately deep, well drained soils formed in colluvium and residuum weathered from greenstone or other metavolcanic rocks. The Gopheridge soils are on hills. Slopes range from 3 to 90 percent. The mean annual precipitation is about 530 mm and the mean annual air temperature is about 16 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, active, thermic Ultic Haploxeralfs

TYPICAL PEDON: Gopheridge loam on a west-facing, 20 percent, linear slope under blue oak and annual grasses at an elevation of 337 meters. (Colors are for dry soils unless otherwise noted. When described on April 2, 2007 the soil was moist throughout.)

Oi--0 to 3 cm; slightly decomposed plant material; moderately acid (pH 6.0); abrupt smooth boundary. (0 to 3 cm thick)

Oe--3 to 5 cm; moderately decomposed plant material; slightly acid (pH 6.2); abrupt smooth boundary. (0 to 3 cm thick)

A1--5 to 10 cm; reddish brown (5YR 4/4) loam, dark reddish brown (5YR 3/4) moist; 35 percent sand; 19 percent clay; moderate medium granular structure; hard, firm, slightly sticky, nonplastic; many very fine roots throughout; common fine irregular and medium tubular pores; 4 percent subrounded indurated greenstone gravel, 2 percent subrounded indurated quartz gravel; slightly acid (pH 6.4); clear smooth boundary.

A2--10 to 18 cm; yellowish red (5YR 4/6) loam, dark reddish brown (2.5YR 3/4) moist; 36 percent sand; 20 percent clay; moderate medium subangular blocky structure; very hard, firm, slightly sticky, slightly plastic; many very fine and few fine roots throughout; few very fine dendritic tubular and common medium tubular pores; 10 percent subrounded indurated greenstone gravel, 1 percent subrounded indurated quartz gravel; slightly acid (pH 6.1); clear wavy boundary. (Combined thickness of the A horizons is 5 to 20 cm)

Bt1--18 to 36 cm; yellowish red (5YR 4/6) extremely gravelly loam, dark reddish brown (2.5YR 3/4) moist; 34 percent sand; 24 percent clay; moderate medium subangular blocky structure; extremely hard, very firm, moderately sticky, moderately plastic; few very fine, common fine and medium, and few coarse roots throughout; many very fine dendritic tubular and common medium tubular pores; 10 percent faint clay films on all faces of peds; 45 percent subrounded strongly cemented greenstone gravel, 2 percent subrounded indurated quartz gravel, 11 percent subrounded strongly cemented greenstone cobbles, 5 percent subrounded strongly cemented greenstone stones; slightly acid (pH 6.1); gradual smooth boundary. (Combined thickness of the upper Bt horizons is 10 to 35 cm)

Bt2--36 to 53 cm; reddish brown (5YR 4/4) very stony clay loam, dark reddish brown (2.5YR 3/4) moist; 29 percent sand; 37 percent clay; strong medium subangular blocky structure; extremely hard, very firm, moderately sticky, moderately plastic; few very fine, common fine and medium, and few coarse and very coarse roots throughout; many very fine dendritic tubular and few medium tubular pores; 25 percent distinct clay films on all faces of peds; 2 percent subrounded indurated quartz gravel, 36 percent subrounded strongly cemented greenstone gravel, 11 percent subrounded strongly cemented greenstone cobbles, 10 percent subrounded strongly cemented greenstone stones, 5 percent subrounded moderately cemented greenstone paragravel; moderately acid (pH 6.0); clear wavy boundary.

Bt3--53 to 81 cm; red (2.5YR 4/6) extremely stony clay, yellowish red (5YR 4/6) moist; 27 percent sand; 44 percent clay; strong medium subangular blocky structure; extremely hard, very firm, moderately sticky, moderately plastic; few very fine, common fine and medium, and few coarse and very coarse roots throughout; many very fine and common fine dendritic tubular pores; 30 percent distinct clay films on all faces of peds; 5 percent subrounded strongly cemented greenstone gravel, 2 percent subrounded indurated quartz gravel, 20 percent subrounded strongly cemented greenstone cobbles, 40 percent subrounded strongly cemented greenstone stones; moderately acid (pH 5.7); abrupt broken boundary. (Combined thickness of the lower Bt horizons is 15 to 70 cm)

R--81 to 152 cm; strongly cemented greenstone bedrock, fractured at intervals of 10 to 45 cm.

TYPE LOCATION: Calaveras County, California, about 6.3 km (3.9 miles) northeast of Tulloch Reservoir Dam; USGS 7.5 minute topographic quadrangle: Copperopolis, California; WGS84 37.9428596 latitude and -120.7150269 longitude; UTM Zone 10 700783 meters E 4201935 meters N NAD83.

RANGE IN CHARACTERISTICS:

Soil temperature: The mean annual soil temperature at 50 cm is 15 to 18 degrees C and the difference between mean summer and mean winter soil temperature is greater than 6 degrees C. The soils have a thermic temperature regime.

Soil moisture: The soil moisture control section is dry in all parts from about May to October. The soils have a xeric soil moisture regime.

Diagnostic Feature(s):
Ochric epipedon thickness: 5 to 20 cm
Argillic horizon thickness: 35 to 75 cm
Depth to lithic contact: 50 to 100 cm
Paralithic materials are present above the lithic contact in some pedons.

Particle size control section weighted average:
Rock fragments: 35 to 80 percent
Clay content: averages 18 to 35 percent clay

Base saturation: less than or equal to 75 percent in one or more subhorizons of the argillic horizon (by sum of cations).

A horizon
Hue: 5YR, 7.5YR
Value: 4 to 6 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture: loam, silt loam, sandy loam
Clay content: 12 to 25 percent
Rock fragments: 0 to 60 percent
0 to 40 percent gravel
0 to 35 percent cobbles
0 to 15 percent stones
Parafragments: 0 to 15 percent
0 to 10 percent paragravel
0 to 5 percent paracobbles
Reaction: moderately acid to neutral

Bt horizon(s), upper part
Hue: 5YR, 7.5YR
Value: 4 to 7 dry, 3 or 4 moist
Chroma: 4 or 6 dry, 3 to 6 moist
Texture: loam, clay loam, silt loam, silty clay loam, sandy clay loam
Clay content: 18 to 30 percent
Rock fragments: 15 to 75 percent
15 to 50 percent gravel
0 to 35 percent cobbles
0 to 15 percent stones
Parafragments: 0 to 35 percent
0 to 15 percent paragravel
0 to 25 percent paracobbles
Reaction: strongly acid to neutral

Bt horizon(s), lower part
Hue: 2.5YR, 5YR, 7.5YR
Value: 4 to 6, dry or moist
Chroma: 4 or 6, dry or moist
Texture: clay loam, loam, clay, sandy clay loam
Clay content: 25 to 50 percent
Rock fragments: 35 to 80 percent
15 to 75 percent gravel
0 to 60 percent cobbles
0 to 35 percent stones
Parafragments: 0 to 60 percent
0 to 60 percent paragravel
0 to 25 percent paracobbles
Reaction: strongly acid to neutral

COMPETING SERIES: These are the Hetchy, Hurleton, Oroshore, and Gardellones series. Hetchy soils are 50 to 100 cm deep to paralithic contact of metasedimentary rock. Hurleton soils are 50 to 100 cm deep to a lithic contact of intrusive igneous rock. Oroshore soils are 50 to 100 cm deep to a paralithic contact. Gardellones soils are 100 to 150 cm deep to a paralithic contact.

GEOGRAPHIC SETTING: The Gopheridge soils are on backslopes and footslopes of hills. Slopes range from 3 to 90 percent. These soils formed in colluvium and residuum weathered from greenstone and other metavolcanic rocks. Elevation is 80 to 835 meters. The climate is Mediterranean with warm, dry summers and cool, moist winters. The mean annual precipitation is 405 to 875 mm and the mean annual air temperature is 14 to 17 degrees C. The frost free season is 215 to 335 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonanza, Gardellones, Jasperpeak, Loafercreek, and Motherlode soils. Bonanza soils are 25 to 50 cm to a paralithic contact and are on summits, shoulders, and upper backslopes. The competing Gardellones soils are 100 to 150 cm to a paralithic contact and are on lower backslopes and footslopes. Jasperpeak soils are 25 to 50 cm to a lithic contact, and are on shoulders and upper backslopes. Loafercreek soils are have less than 35 percent rock fragments in the particle size control section and are 50 to 100 cm to a paralithic contact. Motherlode soils are have less than 35 percent rock fragments in the particle size control section, are 100 to 150 cm to a paralithic contact. Loafercreek and Motherlode soils are on lower backslopes and footslopes.

DRAINAGE AND PERMEABILITY: Well drained; moderately high to high saturated hydraulic conductivity in the A and upper Bt horizons and moderately low in the lower Bt horizons.

USE AND VEGETATION: This soil is used for rangeland, recreation, wildlife habitat, and homesites. Vegetation is blue oak woodland with wild oat, annual ryegrass, rattlesnake brome, soft chess, red brome, ripgut brome, foxtail fescue, tarweed, and forbs. Scattered interior live oak and foothill pine may be present.

DISTRIBUTION AND EXTENT: Sierra Nevada Foothills in California; MLRA 18. The series is moderately extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES PROPOSED: Calaveras County, California. Source of name is from a nearby physiographic feature.

REMARKS:
Particle Size Control Section for this pedon: 18 to 68 cm
Diagnostic horizons and features recognized in this pedon are:
Ochric Epipedon 0 to 18 cm
Argillic Horizon 18 to 81 cm
Lithic Contact 81 cm

ADDITIONAL DATA:
NASIS User Pedon ID: S2007CA009002
Lab Pedon #: 07N0469

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National Cooperative Soil Survey
U.S.A.