The
formation of
sedimentary rocks in a
marine delta environment is largely influenced by the type of flow responsible for the
deposition of
sediment. Within a delta sedimentary environment, there are three main flowtypes:
Homopycnal Flow
This flow is the immediate, three-dimensional mixing of river and basin water of equal density, accompanied by considerable sediment deposition. This results in intense local mixing of waters and gives rise to turbidite sequences.
Hyperpycnal Flow
The water entering a basin on the floor of a lake or ocean which, because of its relatively high density, flows as a bottom-hugging current and causes sediment to travel a large distance from its point of entry. This type of flow commonly occours during flooding, when sediment-heavy river flows enter basins.
Hypopycnal Flow
The water entering a basin on the floor of a lake or ocean which, because of its relatively low density, takes the form of a buoyant surface plume or jet. This situation is most common when fresh water flows into salt water, because of the differences in density between fresh and salt water.