Poorly Drained Soils with Permafrost in Interior Alaska
1969
Allan, R. J. | Brown, Jerry | Rieger, Samuel
Physical, chemical, and mineralogical properties are presented for five soils with permafrost in interior Alaska. The soils are shallowly thawed, with permafrost usually at 60 cm or less, and with a thick accumulation of organic matter, usually about 25 cm deep, over a gleyed mineral soil. They are classified as Histic Pergelic Cryaquepts in the comprehensive soil classification system adopted by the US Department of Agriculture. Histic Pergelic Cryaquepts are the most extensive soils developed over permafrost in Alaska. In three of the five profiles, particle-size analyses reveal a slight increase (2–4%) in clay content of the thawed mineral soil over that of the permafrost. The coarsest horizon in all five profiles contains only 48% sand. The dominant texture is silt loam. In one of the profiles, base saturation increases (52–90%) with depth in the thawed mineral soil, then remains fairly constant in the permafrost. Percent Zr (0.02%) remains constant in the coarse silt fraction of all horizons of all five profiles both above and in the permafrost. The dominant clay minerals in the thawed horizons were vermiculite and kaolinite.
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