Changes

* ''[[Tidally dominated deltas]]'' (such as the Gulf of Papua delta) are those in which the tidal energy exceeds that of either wave or fluvial processes. Sand deposited by the distributaries is reworked by tidal currents into elongate sand ridges that are generally perpendicular to the regional coastline.

* ''[[Tidally dominated deltas]]'' (such as the Gulf of Papua delta) are those in which the tidal energy exceeds that of either wave or fluvial processes. Sand deposited by the distributaries is reworked by tidal currents into elongate sand ridges that are generally perpendicular to the regional coastline.

Rarely do deltas conform perfectly to these end-members. In general they are transitional, giving rise to complexity and variability in the geometry and reservoir heterogeneities of resulting sandstone bodies (e.g., Sneider et al.<ref name=pt06r130>Sneider, R. M., Tinker, C. N., Meckel, L. D., 1978, Deltaic environment reservoir types and their characteristics: Journal of Petroleum Technology, Nov., p. 1538–1546.</ref>).

Rarely do deltas conform perfectly to these end-members. In general they are transitional, giving rise to complexity and variability in the geometry and reservoir heterogeneities of resulting sandstone bodies (e.g., Sneider et al.<ref name=pt06r130>Sneider, R. M., Tinker, C. N., Meckel, L. D., 1978, Deltaic environment reservoir types and their characteristics: Journal of Petroleum Technology, Nov., p. 1538–1546.</ref>).  For more information on deltas, see also [[Deltaic environments]],  [[Delta plain, upper]], [[Delta plain, lower]], and [[Delta plain, subaqueous]].

[[Distributary mouth bar]]s and channel deposits ([[:file:lithofacies-and-environmental-analysis-of-clastic-depositional-systems_fig3.png|Figure 3h]]) comprise the best reservoir quality bodies within a delta system. The general upward-coarsening character of distributary mouth bars tends to produce sandstone bodies that have their greatest [[permeability]] at the top. Conversely, distributary channel sandstone bodies are usually upward-fining and have their greatest permeability at the base.<ref name=pt06r130 /> Preferred orientation of flow may be expected to follow paleochannel trends.

[[Distributary mouth bar]]s and channel deposits ([[:file:lithofacies-and-environmental-analysis-of-clastic-depositional-systems_fig3.png|Figure 3h]]) comprise the best reservoir quality bodies within a delta system. The general upward-coarsening character of distributary mouth bars tends to produce sandstone bodies that have their greatest [[permeability]] at the top. Conversely, distributary channel sandstone bodies are usually upward-fining and have their greatest permeability at the base.<ref name=pt06r130 /> Preferred orientation of flow may be expected to follow paleochannel trends.