Skip to main content Accessibility help
×
Hostname: page-component-848d4c4894-hfldf Total loading time: 0 Render date: 2024-05-18T01:35:45.733Z Has data issue: false hasContentIssue false

3 - The Fleurieu Peninsula coast

Published online by Cambridge University Press:  25 July 2017

Robert P. Bourman
Affiliation:
University of Wollongong
Colin V. Murray-Wallace
Affiliation:
University of Wollongong
Nick Harvey
Affiliation:
University of Adelaide
Get access

Summary

Introduction

Fleurieu Peninsula, the smallest of South Australia's three main peninsulas, was named by Nicolas Baudin in 1802 after Captain Charles Pierre Claret de Fleurieu, a Member of the Institute of France, which promoted Baudin's expedition. The Fleurieu coast, which extends about 140 km from Sellicks Beach in the north to Middleton in the southeast (Figure 3.1), is bedrock-dominated and exhibits cliffs, bluffs, rocky islands, shore platforms and reefs; sandy pocket beaches occupy small bays where valleys intersect the coast. More extensive beaches at Normanville, Tunkalilla and Victor Harbor front last interglacial embayments, formed when sea level was about 2 m higher than present. Vast arrays of geological features, past ice ages, climatic changes, prior shoreline positions and erosional and depositional stream activities have impacted on the coast.

Geological evolution

Part of the South Mount Lofty Ranges, Fleurieu Peninsula is underlain by resistant, folded rocks and granite intrusions, now exposed at the coast due to progressive tectonic uplift and erosion (Figure 3.2). During the Early Permian (299 to 290 Ma), an ice sheet some 1000 to 2000 m thick covered Fleurieu Peninsula, travelling towards the northwest. The ice sheet aided exposure of the Encounter Bay Granites, produced the present distribution of granite headland and islands of Encounter Bay, eroded deep valleys such as Backstairs Passage and deposited great thicknesses of glacial sediments, which today provide sand sources for many beaches.

Throughout the Mesozoic (253 to 66 Ma), Fleurieu Peninsula was exposed to continual weathering and erosion. After the separation of Australia and Antarctica, various marine incursions invaded the Paleogene and Neogene (65 to 2.6 Ma) basins fringing Fleurieu Peninsula and partially re-excavated Permian valleys within the ranges. Progressive tectonic uplift of Fleurieu Peninsula is revealed by the offset of these Cenozoic marine sediments. In the Myponga Basin, limestone 20 Ma old occurs at up to 240 m APSL, while at Sellicks Beach, only 12 km away, it extends below sea level. Active tectonism has uplifted the peninsula largely as a single tectonic block, tilted slightly to the south and exposing resistant bedrock at the coast to initiate and maintain the rugged, cliffed Fleurieu coast.

Type
Chapter
Information
Publisher: The University of Adelaide Press
Print publication year: 2016

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×