Geology Reference
In-Depth Information
Figure 13.16
Types of estuary: a physiographic classification. Fjords are drowned glacial troughs (p. 255). Rias are
erstwhile river valleys drowned by Holocene sea-level rise. They may include mudflats and have barrier spits at their
mouths. Coastal plain estuaries are, as their name suggests, estuaries in coastal plains. Bar-built or barrier estuaries have
barriers that enclose broad and shallow lagoons. Blind estuaries are closed by an ephemeral bar and stagnate in dry
seasons. Delta-front estuaries are associated with river deltas. Tectonic estuaries are formed by folding, faulting, or other
tectonic processes. Part of the San Francisco Bay, California, estuary comes under this heading.
Source:
Adapted from Fairbridge (1980)
