Geological field guides as educational tools: the Coorong, South Australia

Abstract

The South Australian (SA) Division of the Geological Society of Australia (GSAust) has a working subcommittee responsible for preparation of geological field guides. The target audience for these guides comprises persons who have an interest in natural environments, but who do not necessarily have specialist education in the Earth sciences. Care is taken to avoid excessive and unnecessary use of jargon, but where required, technical terms are used with appropriate explanations; ‘dumbing down’ is avoided and suitable references are cited for those who seek further information. Field guides can be downloaded from the GSAust web site. Later editions may be updated for mobile devices. The over-arching aim of the subcommittee is to contribute to public education. The Coorong is a back-barrier coastal lagoon that, together with Lake Alexandrina and Lake Albert, constitute the modern estuary of the River Murray. The Younghusband Peninsula is a Holocene beach-dune barrier that was formed as the rising postglacial sea transported sandy sediment shoreward from the exposed Lacepede Shelf. The peninsula stabilised following culmination of the postglacial marine transgression, at the same time isolating a narrow back-barrier lagoon, the Coorong, from the direct impact of the Southern Ocean. The Coorong is a landscape icon rated highly as a tourist attraction. It has importance for ornithologists and other scientists (including geologists) and is the ancestral home of the Ngarrindjeri people. There is a diverse group of people who might be interested in a well-presented and authoritative field guide to this area. The Coorong and associated features thus provide a landscape that underpins consideration of two major concepts: Earth’s global climate has greatly varied during the Pleistocene; glacial and interglacial climatic events have been widely identified within a consistent chronologic framework; and the present global climate is interglacial. Sea-level is lower during cooler glacial times when increased amounts of water are stored as ice on land, particularly in the polar and highland (alpine) regions; sea-level rises during warmer interglacial times when meltwater from glaciers and ice sheets flows into the oceans; and in the present warm-interglacial climate sea-level is high.

Keywords:

• Coorong
• geological education
• Holocene
• Pleistocene
• sea-level
• South Australia
• tourism

Acknowledgements

Rachel Froud is acknowledged for her professional formatting of the materials comprising the field guides. Images provided by Google Earth feature as illustrative figures. The substance of this paper was presented at the 2016 Australian Earth Sciences Convention, Adelaide. It is submitted for publication at the request of Margaret Brocx, National Convenor Geoheritage, GSAust. Barry Cooper, Jim Jago and two anonymous reviewers are thanked for their helpful comments.

Disclosure statement

No potential conflict of interest was reported by the author.