A tombolo is a narrow sandy isthmus that eventually joins an island to another piece of land by the deposition of sand and other sediments over time. The theory is that what is now ‘the neck’ was a collection of sand that built up over time, eventually joining the two islands of North and South Bruny together.
During the last ice age, the area to the West of what is now called ‘the neck’ on Bruny Island, was joined to mainland Tasmania. What is now the D’Entrecasteaux Channel, used to be a broad shallow valley on the lower reaches of the North-West bay and Huon rivers, probably an area of marshes and wetlands. There may have been sea entrances into this valley.
As the sea levels rose at the end of the ice age, 12,000 years ago, the sand that was washing down from the rivers then built up between two hills that had become islands. Over time this continued as more sand was brought in by currents and winds. And that dune that now forms ‘the neck’ eventually connected North and South Bruny perhaps 6000 years ago. A lot of this sand that we now see at the neck has come from the North-West bay, Huon rivers, and from the land that was drowned in between when the last ice age ended. A lot of this would have been part of the soil profile between here and across the Channel to Kettering and mainland Tasmania.
During the last ice age, the area to the West of what is now called ‘the neck’ on Bruny Island, was joined to mainland Tasmania.
Bob Graham
A tombolo is a narrow sandy isthmus that eventually joins an island to another piece of land by the deposition of sand and other sediments over time. The theory is that what is now ‘the neck’ was a collection of sand that built up over time, eventually joining the two islands of North and South Bruny together.
During the last ice age, the area to the West of what is now called ‘the neck’ on Bruny Island, was joined to mainland Tasmania. What is now the D’Entrecasteaux Channel, used to be a broad shallow valley on the lower reaches of the North-West bay and Huon rivers, probably an area of marshes and wetlands. There may have been sea entrances into this valley.
As the sea levels rose at the end of the ice age, 12,000 years ago, the sand that was washing down from the rivers then built up between two hills that had become islands. Over time this continued as more sand was brought in by currents and winds. And that dune that now forms ‘the neck’ eventually connected North and South Bruny perhaps 6000 years ago. A lot of this sand that we now see at the neck has come from the North-West bay, Huon rivers, and from the land that was drowned in between when the last ice age ended. A lot of this would have been part of the soil profile between here and across the Channel to Kettering and mainland Tasmania.
During the last ice age, the area to the West of what is now called ‘the neck’ on Bruny Island, was joined to mainland Tasmania.
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Geological History of Bruny Island
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