LOCATION CHITINA AK
Established Series
Rev. MHC/JPM
02/2022
CHITINA SERIES
The Chitina series consists of very deep well drained soils formed in silty loess. Chitina soils are on hills, broad high lacustrine terraces and stream terraces. Slopes range from 0 to 20 percent. Mean annual temperature is about 26 degrees F. and the average annual precipitation is about 12 inches.
TAXONOMIC CLASS: Coarse-silty, mixed, superactive Cumulic Haplocryolls
TYPICAL PEDON: Chitina silt loam - on a 1 percent slope under grasses and forbs at 1100 feet elevation.
Oi--2 inches to 0; partially decomposed moss, roots, and litter; clear smooth boundary. (1 to 5 inches thick)
A--0 to 2 inches; very dark grayish brown (10YR 3/2) and dark brown (10YR 3/3) moist silt loam; colors occur in fine horizontal streaks, with common fine distinct brown (7.5YR 4/4) and strong brown (7.5YR 4/6) mottles; weak very fine subangular blocky structure; very friable, nonsticky and nonplastic; many fine and medium roots; neutral (pH 7.0); abrupt wavy boundary. (2 to 12 inches thick)
A/C--2 to 20 inches; streaked colors dominated by very dark grayish brown (10YR 3/2), dark grayish brown (10YR 4/2), and strong brown (7.5YR 4/2) moist silt loam and very fine sandy loam; colors occur in fine discontinuous horizontal streaks with small lenses of charcoal; weak medium platy structure; very friable, nonsticky and nonplastic; common very fine and fine roots; mildly alkaline (pH 7.4); abrupt wavy boundary. (6 to 32 inches thick)
C1--20 to 32 inches; streaked colors of dark brown through black (10YR 2/1, 2/2, and 3/2) moist silt loam and very fine sandy loam; weak thick platy structure; very friable, nonsticky and nonplastic; 10 percent dark grayish brown (2.5Y 4/2) and dark gray (5Y 4/1) thin convoluted streaks; common very fine and few fine roots; mildly alkaline (pH 7.6); abrupt wavy boundary. (0 to 12 inches thick)
C2--32 to 50 inches; very dark grayish brown (10YR 3/2) and dark gray (2.5YR 4/1) moist very fine sandy loam; prominent brown (7.5YR 4/4) mottles; few very fine roots; mildly alkaline (pH 7.8); abrupt wavy boundary. (0 to 20 inches thick)
2C3-50 to 60 inches; dark gray (5Y 4/1) moist silty clay; strong very fine subangular blocky structure; friable, sticky and plastic; strongly effervescent with disseminated lime; moderately alkaline (pH 8.2).
TYPE LOCATION: Cooper River Area, Alaska; 9 miles southeast of Kenny Lake; about 2000 feet west of the NE corner of section 28, T.2S., R.4E., Copper River Meridian.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 32 to 35 degrees F. Thickness of the loess mantle ranges from 40 to more than 60 inches. The particle size of the control section commonly is silt loam but includes mucky silt loam, silt and very fine sandy loam with less than 15 percent fine sand or coarser. Reaction is neutral or mildly alkaline in the upper horizons, ranging to moderately alkaline in the contrasting substratum.
The A horizon matrix has moist hue of 7.5YR, 10YR, or 2.5Y; moist value of 2 or 3; moist chroma of 1, 2, or 3. This horizon contains streaks and strata of varying thickness. Mottles are commonly present. Reaction is neutral or mildly alkaline.
The A/C horizon when present has dominant moist hue of 7.5YR, 10YR, or 2.5Y; moist value of 2, 3, or 4; moist chroma of 1, 2, or 3. Colors often occur in horizontal and convoluted streaks and patches, with thin strata of charcoal often present. Reaction is neutral or mildly alkaline.
The C horizons have moist hue of 10YR, 2.5Y, 5Y, or neutral; value moist of 2, 3, 4 or 5; and chroma moist of 0, 1, 2, 3 or 4. Reaction is neutral or mildly alkaline.
The 2C horizon, when present, has moist hue of 2.5Y or 5Y; value moist of 4 or 5; and chroma moist of 1 or 2. Texture is silty clay, silty cay loam, or clay. Rock fragment content ranges from 0 to 15 percent subangular cobbles and pebbles. Effervescence ranges from slightly to strongly. Free carbonates are disseminated throughout.
COMPETING SERIES: There are no competing series in the same family.
GEOGRAPHIC SETTING: Chitina soils formed in a silty loess mantle on hills, broad lacustrine terraces and stream terraces. Slopes range from 0 to 20 percent.
The climate is subarctic continental with long, cold winters and short, warm summers. Mean annual precipitation ranges from 8 to 17 inches and the mean annual snowfall is 39 to 68 inches. Mean January temperature is minus 10 degrees F., mean July temperature is 56 degrees F., and the mean annual temperature ranges from 23 degrees to 27 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Copper River and
Kenny Lake series on the same landform. Copper River soils are the permafrost counterpart of the Chitina series. The organic mat of the Copper River soils is undisturbed, resulting in better insulation, lower soil temperature, and permafrost within the control section. Kenny Lake soils are in similar positions but have lacustrine material within 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; runoff is slow to rapid; permeability is moderate.
USE AND VEGETATION: Most areas of Chitina soils have native vegetation of white spruce, quaking aspen, paper birch, and willows. Most areas have been burned, resulting in the transition from Copper River to Chitina soils. The successional state of vegetation in a given area is closely related to the fire history. Small areas are cleared and used for small grains, grass, and vegetables.
DISTRIBUTION AND EXTENT: Copper River Basin. The series is of moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES PROPOSED: Copper-Chitina Area, Alaska, 1962.
REMARKS: Diagnostic horizons and features recognized in this pedon include: a mollic epipedon from 0 to 32 inches; epipedon stratified with irregular carbon decrease; cryic temperature regime; coarse-silty particle size class from 10 to 40 inches.
The Chitina series is a thawed counterpart of the permafrost Copper River series.
ADDITIONAL DATA: Laboratory data is available for this soil: NSSL numbers 81P4058-4081.
National Cooperative Soil Survey
U.S.A.