In order to depict the nature of the weathering processes operating in the arctic regions, 4 Arctic Brown soil profiles from northern Alaska were studied. Examination of the sand and clay fractions indicates that chemical weathering is in operation; its magnitude, however, is of low order. Acid conditions in the surface facilitate the solution of carbonates, but their removal is incomplete as reprecipitation occurs within the profile. Because of increased concentration of Fe-stained opaque minerals near the surface, oxidation of Fe-bearing minerals was strongly indicated. On very sandy quartzose profiles, Fe, Al, and Mn are partially mobilized and partially translocated, suggesting a weak podzolic process. Clay-size minerals consist mainly of hydrous mica, kaolinite, chlorite, quartz, goethite, and feldspar. Hydrous mica, the most abundant clay mineral, was more hydrated at the surface, and goethite was present only in the surface horizon. Alteration of feldspar into a claylike substance was noted, but well-crystallized feldspar persisted in the clay fraction. A concentration of fines was present in the surface horizon of all Arctic Brown soil profiles. Whether this fine material forms in situ or is a result of aeolian deposition remains a moot question.