LOCATION GASQUET            CA 
Established Series
Rev: AMP/SRM/JPS/ET
05/2007

GASQUET SERIES


The Gasquet series consists of very deep, well drained soils formed in material weathered from serpentinized peridotite. Gasquet soils are on mountains and have slopes of 9 to 50 percent. The mean annual precipitation is 2670 millimeters (105 inches) and the mean annual temperature is 10 degrees C (50 degrees F).

TAXONOMIC CLASS: Fine, parasesquic, mesic Typic Haploxerults

TYPICAL PEDON: Gasquet stony loam - on a southwest-facing slope of 25 percent under Douglas-fir, sugar pine and shrubs at 171 meters (560 feet) elevation. (Colors are for dry soil unless otherwise stated. When described on 8/24/78 the soil was dry in the upper 40 inches and moist below).

Oi--0 to 2 centimeters (0 to 1 inch); fresh and decomposing leaf and needle litter; strongly acid (pH 5.3). (0 to 10 centimeters thick)

A--2 to 25 centimeters (1 to 10 inches); reddish yellow (5YR 6/6) stony loam, reddish brown (5YR 4/3) moist; moderate very fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, many medium, common coarse roots; many very fine interstitial and tubular pores; 10 percent stones; moderately acid (pH 6.0); clear smooth boundary. (8 to 25 centimeters thick)

Bt1--25 to 56 centimeters (10 to 22 inches); red (2.5YR 4/6) stony clay loam, yellowish red (5YR 4/6) moist; weak very fine subangular blocky parting to strong very fine granular structure; slightly hard, firm, moderately sticky and moderately plastic; few very fine, fine, medium and coarse roots; many very fine interstitial and tubular pores; common distinct clay films on faces of peds and on surface along pores; 15 percent stones; slightly acid (pH 6.2); gradual smooth boundary. (10 to 30 centimeters thick)

Bt2--56 to 109 centimeters (22 to 43 inches); dark red (2.5YR 3/6) stony clay loam, yellowish red (5YR 4/6) moist; moderate very fine subangular blocky parting to moderate fine granular structure; slightly hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; many very fine interstitial and tubular pores; common distinct clay films on faces of peds and on surfaces along pores; 15 percent stones; slightly acid (pH 6.4); gradual smooth boundary. (25 to 76 centimeters thick)

Bt3--109 to 137 centimeters (43 to 54 inches); yellowish red (5YR 4/6) stony silty clay loam, reddish brown (5YR 4/4) moist; moderate very fine subangular blocky parting to moderate fine granular structure; moderately hard, firm, moderately sticky and moderately plastic; few fine roots; many very fine interstitial pores; common distinct clay films on faces of peds and on surfaces along pores; 15 percent stones; slightly acid (pH 6.5); clear smooth boundary. (25 to 56 centimeters thick)

Bt4--137 to 155 centimeters (54 to 61 inches); strong brown (7.5YR 5/6) stony silty clay loam, strong brown (7.5YR 4/6) moist; weak very fine subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; few medium roots; common very fine interstitial pores; few distinct clay films on faces of peds and on surfaces along pores; 15 percent stones; slightly acid (pH 6.4). (25 to 56 centimeters thick)

TYPE LOCATION: Del Norte County, California off an old cat road fire line about 0.2 mile from Old Gasquet Toll Road, about 300 yards upslope from cat road; NE 1/4, SW 1/4 sec. 21, T.17N, R.2E, HBLM. Gasquet Quadrangle.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil is usually dry in all parts from June 15 to October 15 and moist in all parts from November 15 to April 15. The soils have a xeric moisture regime.

Soil temperature: The mean annual soil temperature is 10 to 15 degrees C (50 to 59 degrees F). The difference between mean summer and mean winter temperature is 6 to 10 degrees C.

The base saturation (by Hach Kit) is 20 to 30 percent in the argillic horizon.

The ratio of Fe203 plus gibbsite to clay is greater than 0.2.

Surface stones range from 3 to 15 percent.

The particle-size control section:
Rock fragments: 10 to 35 percent
Clay content: 35 to 45 percent

O horizon

Hue: 10YR.
Value: 2 through 6 dry and moist.
Chroma: 1 through 4 dry and moist.

Texture: slightly decomposed organic material.
Wood fragments: 0 to 35 percent.
Reaction: moderately to very strongly acid.

A horizon

Hue: 5YR or 7.5YR.
Value: 3 through 6 dry, 3 or 4 moist.
Chroma: 4 through 6 dry, 3 or 4 moist.

Texture of fine earth: loam or clay loam.
Rock fragments: 0 to 20 percent cobbles and 10 to 20 percent stones.
Clay content: 23 to 30 percent.
Reaction: slightly or moderately acid.

Bt horizon

Hue: 2.5YR, 5YR, or 7.5YR.
Value: 3 through 5 dry, 4 or 5 moist.
Chroma: 4 through 6 dry, 4 through 8 moist.

Texture of fine earth: clay loam, silty clay loam, or clay.
Rock fragments: 0 to 15 percent cobbles and 5 to 20 percent stones.
Clay content: 35 to 50 percent.
Reaction: neutral to moderately acid.

COMPETING SERIES: At this time there are no other series in this family.

GEOGRAPHIC SETTING: Gasquet soils are on mountain slopes. Slopes are 9 to 50 percent. Elevations are 156 to 1148 meters (510 to 3500 feet). The soils formed in material weathered from serpentinized peridotite. The climate is humid with warm, dry summers and cool, wet winters. Mean annual precipitation is 2290 to 3050 millimeters (90 to 120 inches). Mean January temperature is 3 degrees C (37 degrees F.), and mean July temperature is 17 degrees C (63 degrees F.). Mean annual temperature is 10 to 15 degrees C (50 to 59 degrees F). Frost-free season is estimated to be about 140 to 180 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Jayel, Oragran, Walnett, and Weitchepec soils. The Jayel and Weitchepec soils are 50 to 100 centimeters (20 to 40 inches) to a lithic contact. Oragran soils are 20 to 50 centimeters (10 to 20 inches) to a lithic contact. Walnett soils have greater than 35 percent rock fragments in the particle-size control section. Jayel, Oragran, and Weitchepec soils are on convex to strongly convex positions. Walnett soils are in linear to slightly convex mountain slopes positions.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high runoff; moderately low to low saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for timber production, recreation, watershed, and mineral resources. Native vegetation is Douglas-fir and sugar pine with some incense-cedar, and an understory of tanoak, white leaf manzanita, red and California evergreen huckleberry, California coffeeberry, and poison oak.

DISTRIBUTION AND EXTENT: Northwestern California. The series is not extensive.

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

SERIES ESTABLISHED: Del Norte County, California, 1981. Series name is coined.

REMARKS: This series was established to identify and map a new family in a survey area that classified soil map unit components only to the family level. Updated to series level for Soil Survey of Humboldt and Del Norte Counties, December 2005.

ADDITIONAL DATA: A reference sample for mineralogy was sent to the Lincoln Laboratory, 1979. Sample No. S79CA015-6. The particle-size distribution and mineralogy were verified by lab data. Additional data is needed regarding organic carbon and moisture and temperature regimes, also data for low CEC (C16 req/100g) for oxidic subgroups or oxisols.

Source: 10th Edition of the Keys to Soil Taxonomy.


National Cooperative Soil Survey
U.S.A.