The coastal cliffs of Beaumaris, Victoria, are not only a scenic landmark but also a site of significant geological interest. The blunt V-shaped landform known as the Beaumaris Peninsula, marked by Table Rock Point, reveals steeply folded rock layers collectively called the Beaumaris Monocline. These cliffs date back to the Tertiary period and sit atop older Silurian formations, including the Fyansford rock layers. Prominent among these is the 15-meter-thick Beaumaris Sandstone, capped by the yellowish Red Bluff Sandstone, with hard ironstone in the upper layers and small reefs running parallel to the shoreline. Fine sandy marl, calcareous concretions, and a thin gravelly bed with phosphate and iron nodules further enrich the geological profile, with detached nodules often visible at the cliff base.

The monocline’s folded layers create a dramatic visual along the coastline, tilting almost 30 degrees toward the southeast and extending out to sea. This geological structure also forms a drainage divide separating the Gardiners Creek-Dandenong Creek system from the Carrum Swamp. Visitors walking the cliff-top path at Wells Road can observe the jagged remains of these ancient strata, especially during low tide.

Beaumaris is also globally recognized for its fossil deposits, particularly behind Keefer’s Fishermen’s Wharf. Fossils dating from the Late Miocene to Early Pliocene—approximately 12 to 6 million years ago—have been uncovered here, including shells, sea urchins, crabs, foraminifera, as well as the remains of whales, sharks, rays, dolphins, birds, and marsupials. These discoveries have contributed to numerous scientific studies, highlighting the area’s importance in understanding Australia’s prehistoric marine and terrestrial ecosystems.

The Beaumaris cliffs thus offer a rare combination of natural beauty, geological intrigue, and paleontological significance, making them a remarkable site for both science enthusiasts and casual visitors alike.