||Alaska Univ., College. Inst. of Marine Science.;National Oceanic and Atmospheric Administration, Rockville, Md. Office of Sea Grant.;Geological Survey, Reston, Va. Office of Marine Geology.;Environmental Protection Agency, Washington, D.C.
Polar deltas, typified by those on Alaska's North Slope, which have their drainage basins totally in the permafrost region and discharge into a polar sea, are significantly different from lower latitude deltas. In the arctic, features classically related to delta-front platform and slope facies are not well defined and certain continental facies are either nonexistent or less well developed. Except during occasional storms the North Slope deltas are exposed to low energy hydraulic conditions. Mean size is the only textural parameter that can be used to differentiate sediments of the estuary, lagoon, coastal beach, bay and open marine environments. Terrigenous input primarily determines the clay mineral assemblage at any locality in the river. However, differences between fluvial and marine deltaic environments are discernible. Broad facies variations within the nearshore materials suggest that clay mineral suites may be of use in explaining sediment transport directions. Differences in the chemistry of arctic and lower latitude deltaic sediments are recognizable as well as are variations among the subfacies of the arctic deltas.