LOCATION WUKUSICK                CA

Tentative Series
JCR/AGB/TKK/JW
03/2023

WUKUSICK SERIES

The Wukusick series consists of very deep, well drained soils formed in colluvium over residuum from mafic plutonic rocks such as diorite, granodiorite, or gabbro, and their metamorphosed counterparts. The Wukusick soils are on high hills and mountain slopes. Slopes range from 3 to 60 percent. The mean annual precipitation is about 770 mm and the mean annual air temperature is about 13 degrees C.

TAXONOMIC CLASS: Fine, mixed, subactive, mesic Ultic Palexeralfs

TYPICAL PEDON: Wukusick sandy loam on a northeast facing, convex, 46 percent slope, under cover of ponderosa pine, California black oak, canyon live oak and mountain misery at an elevation of 893 meters. (Colors are for dry soils unless otherwise noted. When described on November 2, 2006 the soil was moist throughout.)

Oi--0 to 6 cm; slightly decomposed plant material.

Oe--6 to 8 cm; moderately decomposed plant material; abrupt smooth boundary. (Combined thickness of Oi and Oe horizons [where present] is 4 to 10 cm)

A1--8 to 12 cm; brown (7.5YR 4/2) sandy loam, dark reddish brown (5YR 2.5/2) moist; 58 percent sand; 18 percent clay; strong medium granular structure; moderately hard, friable, nonsticky, nonplastic; common very fine and fine roots and few medium and coarse roots throughout; many fine and medium irregular pores; 8 percent subrounded indurated diorite gravel; few very fine weathered biotite mica flakes; slightly acid (pH 6.5); clear wavy boundary.

A2--12 to 25 cm; brown (7.5YR 4/2) stony sandy loam, dark reddish brown (5YR 3/2) moist; 56 Percent sand; 19 percent clay; moderate medium subangular blocky structure; moderately hard, friable, slightly sticky, slightly plastic; few very fine and fine roots throughout and common medium to very coarse roots throughout; many very fine to medium tubular pores; 8 percent subrounded indurated diorite gravel, 2 percent subangular indurated diorite cobbles, 10 percent subangular indurated diorite stones; few very fine weathered biotite mica flakes throughout; slightly acid (pH 6.5); clear wavy boundary. (combined thickness of A horizons is 15 to 30 cm)

BA--25 to 45 cm; brown (7.5YR 4/4) stony sandy clay loam, dark reddish brown (5YR 3/3) moist; 55 percent sand; 21 percent clay; moderate medium subangular blocky structure; moderately hard, friable, slightly sticky, slightly plastic; few very fine to very coarse roots throughout; common very fine to medium tubular pores; 10 percent faint silt coats on all faces of peds; 3 percent subrounded indurated diorite gravel, 2 percent subangular indurated diorite cobbles, 12 percent subangular indurated diorite stones; few very fine weathered biotite mica flakes throughout; moderately acid (pH 5.9); clear wavy boundary. (Thickness of BA is from 15 to 30 cm)

Bt1--45 to 88 cm; yellowish red (5YR 4/6) clay, red (2.5YR 4/6) moist; 40 percent sand; 42 percent clay; moderate coarse subangular blocky structure; extremely hard, firm, slightly sticky, slightly plastic; few very fine to coarse roots throughout; few very fine to medium tubular pores; 2 percent faint clay films and 5 percent faint silt coats on all faces of peds; common very fine weathered biotite mica flakes throughout; moderately acid (pH 5.7); clear smooth boundary.

Bt2--88 to 142 cm; red (2.5YR 4/6) clay, red (2.5YR 4/6) moist; 38 percent sand; 43 percent clay; moderate very coarse subangular blocky structure; very hard, firm, moderately sticky, moderately plastic; few very fine and fine roots throughout; few very fine to medium tubular pores; 10 percent distinct clay films on all faces of peds; common very fine weathered biotite mica flakes throughout; strongly acid (pH 5.4); gradual smooth boundary.

Bt3--142 to 292 cm; red (2.5YR 4/8) clay loam, red (2.5YR 4/6) moist; 44 percent sand; 33 percent clay; moderately hard, friable, slightly sticky, slightly plastic; few very fine and fine roots throughout; few very fine and fine tubular pores; 5 percent faint clay films on all faces of peds; many very fine weathered biotite mica flakes throughout; strongly acid (pH 5.3). (Combined thickness of Bt horizons exceeds 130 cm)

Cr--292 to 317 cm; 40 percent yellowish red (5YR 4/6) and 60 percent reddish yellow (7.5YR 6/6); moderately cemented granodiorite bedrock, fractured at intervals of greater than 10 cm, 40 percent yellowish red (5YR 5/6) and 60 percent red (2.5YR 4/8) moist; many very fine weathered biotite mica flakes throughout.

TYPE LOCATION: Tuolumne County, California, about 2.5 km (1.5 mi) north of the community of Tuolumne City; USGS 7.5 minute topographic quadrangle: Tuolumne, California. WGS84: 37.986137 latitude and -120.235611 longitude; UTM zone 10 4207883 meters N 742775 meters E NAD83;

RANGE IN CHARACTERISTICS:

Soil temperature: The mean annual soil temperature at 50 cm is 12 to 15 degrees C and the difference between mean summer and mean winter soil temperature is greater than 6 degrees C. The soils have a mesic temperature regime.

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

Diagnostic Feature(s):
Umbric epipedon thickness: 20 to 50 cm
Argillic horizon thickness: 130 to over 200 cm
Depth to abrupt textural change: 25 to 75 cm (may not be present in all pedons)
Depth to paralithic contact: greater than 200 cm

Particle size control section weighted-average:
Rock fragments: less than 20 percent (typically less than 5 percent)
Clay content: 35 to 50 percent

A horizons
Hue: 5YR, 7.5YR
Value: 4 or 5 dry, 2.5 or 3 moist
Chroma: 3 or 4 dry, 2.5 or 3 moist
Texture: loam, sandy loam, sandy clay loam
Clay content: 14 to 27 percent
Rock fragments: 0 to 20 percent
0 to 20 percent gravels
0 to 10 percent cobbles
0 to 10 percent stones
Reaction: strongly acid to neutral

BA horizons
Hue: 5YR, 7.5YR
Value: 4 or 5 dry, 2.5 or 3 moist
Chroma: 3 or 4 dry, 2.5 or 3 moist
Texture: loam, sandy loam, sandy clay loam
Clay content: 14 to 27 percent
Rock fragments: 0 to 20 percent
0 to 20 percent gravels
0 to 10 percent cobbles
0 to 10 percent stones
Reaction: moderately acid to neutral

Bt (upper) horizons
Hue: 2.5YR, 5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 4 to 8 dry or moist
Texture: clay loam, clay, sandy clay loam
Clay content: 30 to 45 percent
Rock fragments: 0 to 20 percent
0 to 20 percent gravels
0 to 10 percent cobbles
Reaction: moderately acid to slightly acid

Bt (lower) horizons
Hue: 2.5YR, 5YR, 10R
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 4 to 8 dry or moist
Texture: clay, clay loam, sandy clay loam
Clay content: 30 to 50 percent
Rock fragments: 0 to 20 percent gravels
Reaction: moderately acid to slightly acid

COMPETING SERIES: There are no other series in this family at this time.

GEOGRAPHIC SETTING: The Wukusick soils are on sideslopes and interfluves of high hills, mountaintops and mountainflanks. Slopes range from 3 to 60 percent. These soils formed in colluvium over residuum from mafic plutonic rocks. Elevation is 495 to 1500 meters. The climate is Mediterranean with warm, dry summers and cool, moist winters. The mean annual precipitation is 765 to 1300 mm and the mean annual air temperature is 11 to 16 degrees C. The frost free season is 175 to 260 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chawanakee, Holland, Hotaw, Mantree, Musick, and Shaver soils. Chawanakee and Shaver lack argillic horizons and occur on backslopes. Hotaw has less than 35 percent clay in the particle-size control section, is 50 to 100cm to a paralithic contact, and occurs on crests and shoulders of hills. Holland, Mantree and Musick have less than 35 percent clay in the particle-size control section, are greater than 150 cm to a bedrock contact, and occur in similar landscape positions to Wukusick.

DRAINAGE AND PERMEABILITY: Well drained; moderately low to moderately high saturated hydraulic conductivity in the argillic horizon.

USE AND VEGETATION: This soil is used for timber production, wildlife habitat and watershed. Vegetation is ponderosa pine, incense cedar, sugar pine, Douglas fir, California black oak, canyon liveoak, mountain misery, whiteleaf manzanita, toyon, deerbrush, curl-leaf mountain mahogany, Sierra iris, and Pacific poison oak.

DISTRIBUTION AND EXTENT: Sierra Nevada Mountains of California; MLRA 22A. The series is moderately extensive.

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

SERIES PROPOSED: Tuolumne County, California. The name is coined.

REMARKS:
Particle Size Control Section for this pedon: 45 to 95 cm.

Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon 6 to 45 cm
Abrupt textural change 45 cm
Argillic horizon 45 to 292 cm
Paralithic contact 292 cm

ADDITIONAL DATA:
Pedon information for this type location only:
NASIS User Pedon ID: S2007CA109004
Pedon Type: OSD pedon
Pedon Purpose: laboratory sampling site
Lab Source ID: SSL
Lab Pedon #: 07N0473

Soil classified using the 13th Edition of the Keys to Soil Taxonomy.

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National Cooperative Soil Survey
U.S.A.