Introduction
A meandering Channel or stream has a single channel that winds snakelike through its valley, so that the distance ‘as the stream flows’ is greater than ‘as the crow flies. ‘ As water flows around these curves, the outer edge of water is moving faster than the inner.
With greater distance from the sediment source area, a meandering river becomes more typical. (Figure 1, Idealized block diagram showing a meandering river system over a region of low slope and continual subsidence).
Alluvial flood plains cut by a single meander channel occur in regions characterized by relatively low gradients, fine- to medium-grained sediment, and continuous (non-seasonal) discharge. The boundary between braided channels and a single meander channel is a gradational one, but the distinction is very important for petroleum geology. We have seen that braided systems deposit extensive blankets of sand, some which have served as reservoirs for giant accumulations. Meander channels, by contrast, deposit more localized reservoir sands, which host generally small, elusive stratigraphic traps. Such rivers very often create deltas at their mouths, and thus much of the following discussion on deposition, geometry, and identification has relevance to channels in this more transitional environment. In the sedimentary record, a large number of preserved meander channel facies are associated with deltas.
