Paleoshoreline

[3] The position of paleoshorelines differed greatly from modern shorelines and can be used to reconstruct past sea levels, environments and ecological communities.

Paleoshorelines exist due to unique preservation processes and give insight into the formation and understanding of prominent marine structures.

Average sea level can advance and recede over much longer periods (thousands or millions of years), causing paleoshorelines which may be difficult to identify, but are often found in long lasting coastal structures such as beaches, sand dunes, and coral reefs.

Over geological time, fluctuations in sea level has been primarily driven through the melting and freezing of ice sheets and plate tectonics.

The calcium carbonate used in the shells of many marine invertebrates such as corals, mussels, and clams acts as an important building material that helps with the preservation of paleoshorelines, as they are more resistant to erosion and can maintain their structure through changing sea levels over geologic time.

These structures can indicate distributions of seabed features that are habitats of marine life; they may also reveal the location of coastal resources once used by humans, of archaeological significance.