Depositional Environments in the Colville River Delta.
LOUISIANA STATE UNIV BATON ROUGE COASTAL STUDIES INST
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The Colville River delta is growing northward into the Arctic Ocean at a point about 40 km west of Prudhoe Bay. Within the delta are a number of environments that owe their existence, characteristics and distribution to a variety of interrelated depositional and erosional processes. The subaerial portion about 600 sq km in area of the delta contains a number of distributary channels, a variety of lakes and marshes, extensive sandbars and mudflats and sandbar-bordering lee dunes. Subaqueous environments include channels, levees, distal bars and a complicated prodelta zone. Marine and fluvial processes are basically similar to those occurring in non-arctic deltas -- river flow, tidal action and wave energy are all present. However, both temporal and areal variability is great primarily because of the extreme seasonality of climate. The presence of permafrost and the long-lasting snow and ice cover 8-9 months confine most activitity to a very short period of time. The natura and timing of snowmelt and river and sea ice break up affect depositional rates and locations. Flooding of the subaerial portion of the delta is highly variable from year to year. Ice serves as a damming agent affecting flood levels and deposition amounts. As a transporting agent, ice can carry variable size sediments and thus, areas subject to flooding have occasional erractics among their deposits. Because extensive bars are exposed during most of the non-snow covered period wind deflation and sand dune development are common.
- Geology, Geochemistry and Mineralogy