as at 27/01/2019
The cliffs of Beaumaris Bay have been thrust upwards under pressure and were mainly laid down under the sea some 5.25 – 6 million years ago in the Late Miocene. This ancient orange/red strata is made up of Beaumaris sandstone and is overlain by the more recent grey sand and sandstone from the Pliocene/Pleistocene/Holocene epochs. Through the Beaumaris sandstone are layers of Geothite (natures rust). Below the water line is the Fyansford (calcium phosphate) and nodule layers. Fossils are contained throughout all these Late Miocene strata. The orange/red colour in the cliffs is caused by rust (iron oxide). Iron is sourced from past volcanic eruptions in the vicinity. The cliffs in general rise some 15 to 20 metres from sea level. The Beaumaris monocline is still evidenced in the exposed rocks and the Beaumaris fault is located a short distance off shore. Coastal woodland grows at the top of the cliffs and grasses and other smaller salt resistant plants appear in a patchwork of areas across the face of the cliffs.
Bayside Earth Sciences Society Incorporated No. A0100923K 