LOCATION GINI               ID

Tentative Series
Rev. HLH/WOL
10/2002

GINI SERIES

The Gini series consists of maximal Desert Soils, formed in medium or moderately fine textured alluvium from dominantly rhyolitic tuff or rhyolitic sources. The series has an A or Ap, (probably an A2 when not plowed), B, and cca or (and) IICca horizon sequence. The A or Ap (above the B) have color values greater than 6 dry and 4 moist or have less than 0.6 percent organic matter if not irrigated and less than 1 percent organic matter if irrigated as an average of the horizon. The B2 is moderately fine textured and strongly to moderately developed. A strong ca lies below the noncalcareous B2. The related Mopp series has a weakly developed, medium textured B2, a weak or moderate ca, and is derived from alluvium of mixed sources. The Bereniceton series is transitional between Desert and Sierozem soils, has no texture B, and is derived from mixed alluvium. The Gini series has elevations of about 5,200 feet in an arid continental climate. The mean annual soil temperature ranges from 44 to 47 degrees F., and the mean summer air temperature ranges from 62 to 65 degrees F. The average frost-free season is about 105 to 115 days. The mean annual precipitation is 7 to 7.5 inches and includes 20 inches of snowfall. The precipitation is fairly evenly distributed, except for a slight maximum in May and June. The series covers 2 or 3 square miles and is of minor importance agriculturally.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Haplargids

TYPICAL PEDON: Gini loam (cultivated).

Ap--0 to 6 inches; light brownish-gray (10YR 6/2) loam that is slightly gravelly; dark grayish brown (10YR 4/2) when moist; weak or moderate, very thin platy, breaking to weak, very fine granular structure; slightly hard; friable; slightly sticky; slightly plastic; abundant fine and fibrous roots; many micro interstitial and common very fine tubular pores; noncalcareous; neutral reaction (pH 7.2 tb); abrupt, smooth boundary. 4 to 8 inches thick.

B2--6 to 8 inches; light yellowish-brown (10YR 6/4) gravelly or cobbly clay loam marginal to clay; dark brown (10YR 4/3) when moist; very weak, medium prismatic, breaking to weak or moderate, coarse and medium subangular blocky structure; very hard; firm; very sticky; very plastic; plentiful fine and fibrous roots; few very fine tubular pores; thin or medium, nearly continuous clay films on peds and in channels, which are brown (7.5YR 5/3) when dry and dark brown (7.5 YR 4/3) when moist; noncalcareous; neutral reaction (pH 7.4 btb); clear, wavy boundary. 2 to 5 inches thick.

B3ca--8 to 11 inches; light-brown (7.5YR 6/3) cobbly gravelly clay loam; dark brown (10YR 4/3) when moist; weak coarse subangular blocky breaking to weak very fine subangular blocky structure; very hard; friable; sticky; plastic; plentiful fine and fibrous roots; common very fine tubular pores; thin, patchy, clay films on peds and in channels; moderately calcareous; pebbles lime-coated on lower side; mildly alkaline reaction (pH 8.0 cr); abrupt, wavy boundary. 3 to 5 inches thick.

C1ca--11 to 16 inches; very pale brown (10YR 7/3) gravelly loam marginal to sandy clay loam; light yellowish brown (10YR 6/4) when moist; weak, fine subangular blocky structure; hard; friable; slightly sticky; slightly plastic; plentiful fibrous and fine roots; many very fine tubular pores; thin, patchy clay films in channels; strongly calcareous; moderately alkaline reaction (pH 8.3 cr); abrupt, wavy boundary. 3 to 8 inches thick.

IIC2ca--16 to 21 inches; very pale brown (10YR 7/3) very gravelly coarse sandy loam; light yellowish brown (10YR 6/4) when moist; massive; slightly hard; very friable; slightly sticky; nonplastic; few fibrous and fine roots; many micro interstitial and very fine tubular pores; strongly calcareous; pH 8.4 (tb); clear, wavy boundary. 4 to 7 inches thick.

IIC3ca--21 to 25 inches; light-brown (7.5YR 6/3) very gravelly coarse sandy loam; brown (10YR 4/3) when moist; massive; slightly hard; very friable; slightly sticky; nonplastic; few fine roots; many micro interstitial and very fine tubular pores; moderately calcareous; pH 7.8 (cr); abrupt, smooth boundary. 0 to 6 inches thick.

IIIC4--25 to 35 inches; light-brown (7.5YR 6/3) cobbly, very gravelly loamy coarse sand; brown (10YR 4/3) when moist; massive; soft; very friable; slightly sticky; nonplastic; very few fine roots; many micro and very fine interstitial pores; moderately calcareous; pH 8.0 (cr).

IVC5--35 inches; similar but more cobbly and stony.

RANGE IN CHARACTERISTICS: Loam and gravelly loam types have been mapped. Moderately deep to gravel and sloping phases have been recognized. Where untilled, a very thin may overlie the light or very light colored A2. If not lighter than value of 0 when dry and 4 when moist, the A above the texture B has less than 0.6 percent organic matter if not irrigated or less than 1 percent organic matter if irrigated as an average of the horizon. The B2 ranges from about 32 to 40 percent in clay. The ca contains more than 15 percent carbonates.

GEOGRAPHIC SETTING: Level to sloping alluvial fans and terraces. Slopes range from 0 to 8 percent.

DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium. Permeability of the B horizon is moderately slow and of the underlying sand and gravel, very rapid.

USE AND VEGETATION: Irrigated hay, small grains, pasture, and a few potatoes. Some grazing on the rangeland. Shadescale and sparse Sandberg bluegrass and squirreltail. Winterfat in places.

DISTRIBUTION AND EXTENT: Round Valley area of Custer County, Idaho.

TYPE LOCATION:: 2 miles north of Challis and west of the road by the southwest corner of SE 1/4 SW 1/4 sec. 21, T. 14N., R 19 E., Custer County, Idaho.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES PROPOSED: Custer SCD, Custer County, Idaho. Name from local ranch.

REMARKS: Roman numerals prefixes in the horizon symbols indicate lithologic discontinuities.

OSED scanned by SSQA. Last revised by state on 2/62.

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National Cooperative Soil Survey
U.S.A.