Volcanoes
Approximately 200 million years before the mighty T-Rex stomped across the face of the globe, the rocks on Magnetic Island were created. Molten granite was pushed to the earth’s surface with volcanic force erupting up through the existing land. Around Townsville these form the granite outcrops of Mount Stuart Range, Mount Elliot and our very own Magnetic Island. This all happened about 215 million years before Mt Everest appeared. Geologists refer to this as the Permian period. Over time, fractures and weaknesses in the rock have been exploited and the large outcrops have been eroded to form our current iconic rock formations which are capturing hearts to this day.
The world at the time was dominated by two continents known as Pangaea and Siberia, which were surrounded by a global ocean called Panthalassa. Australia was part of Pangea. Until recently (in geological terms) most of Australia’s continental islands weren’t islands they weren’t part of the mainland.
Rising Sea Level
20,000 years ago the sea level around Australia was about 120m lower than present. 12,000 years ago, as the last great ice age came to an end the vast ice sheets covering the globe melted. Known as the Holocene Transgression, this increased the volume of the oceans and caused sea levels to rise. Vast areas of coastal lowlands disappeared under water. Between 10,000 to 4000 years Magnetic Island was born! Originally Magnetic Island was connected to the mainland between Cape Pallarenda and Kissing Point, as the water rose around Townsville the land was drowned and became a shallow bay called West Channel. If you stand on Cockle Bay Beach today and look towards Cape Pallarenda, the water you can see only reaches about 4m deep. The waters of Cleveland Bay to the East of the island average only 10m deep.
Australia’s first nation peoples have existed on the continent for at least 40,000 years and would have witnessed all these changes. There are a substantial body of stories from the Aboriginal People all around Australia that provide genuine and unique observations of post-glacial sea levels (Reid et al. 2014). These observations and records pre-date modern science’s discovery of sea level change by thousands of years.
There are stories from the Wulgurukaba about how land-based Aboriginal groups would walk to the island for ceremonies from Cape Pallarenda. Pallerenda to Cockle Bay was, and still is, a walk, a swim and a walk.
Stories also exist about how it was possible to walk across from the mainland to Hinchinbrook and Palm Islands. Dixon (1980) tells of stories about a ‘legendary’ man named Girugar who travelled across the land naming various places at a time when it was possible to walk to these islands from the (present) mainland. Figure 1 shows how shallow the waters around Palm and Hinchinbrook Island are.
For the Yidinj people around Cairns there is a common theme in their stories of the coastline being where the barrier reef now stands. Gribble (1933) writes that for the Googanji the Barrier Reef was the original coast line and a river entered the sea near Fitzroy Island. There are many more stories from all around Australia with a similar theme.
Magnetic Island Today
Today Magnetic Island is the largest continental island within the Northern Brigalow Belt Bioregion, and the seventh largest within the Great Barrier Reef World Heritage Area (GBRWHA). It is also one of the highest islands in the GBRWHA with a peak height of 493 metres.
The GBRWHA itself starts at a point just north of Fraser Island and extends to the northern tip of Cape York Peninsula (including islands to the east of the mainland but not Torres Strait). Within this area, there are approximately 3,000 coral reefs, 617 continental Islands (with reefs), and 300 reef islands. But 10,000 years ago most of it was all the Australian mainland.
Learn more and experience her beauty for yourself by booking a tour today.
Acknowledgments
With respect and gratitude, we acknowledge the original Aboriginal owners of the stories we cite, even though their identities are largely lost.
References:
Dixon, RM 1980, The Languages of Australia, Cambridge University Press, Cambridge.
Gribble, ER 1933, The Vanishing Aboriginals of Australia, Australian Board of Missions, Sydney.
Nunn, P & Reid, N 2015, ‘Aboriginal Memories of the Inundation of the Australian Coast from More than 7000 years ago‘, Australian Geographer.
Reid, N, Nunn, P & Sharpe, M 2014, Indigenous Australian stories and sea-level change, 2014.