Foulden Maar is a 23-million year old volcanic crater in inland Otago that is a treasure trove of fossils. But it is under threat from a proposal to mine its diatomite for animal feed.
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Hundreds of significant insect fossils have been discovered at Foulden Maar, including this holotype of a worker ant, Austroponera schneideri. Photo: CC BY 4.0 Uwe Kaulfuss Antweb.org
University of Otago palaeontologist Dr Daphne Lee and botanist Dr Jennifer Bannister say the site has yielded large numbers of paper-thin fossils, including many leaves, as well as flowers, fruits and pollen. Some of the leaves still have their cuticle intact.
There are also complete fish fossils and many different insects, which have significantly increased our understanding of this group in prehistoric New Zealand.
The fossils include scale insects still attached to plants.
A fossil fish from Foulden Maar. Photo: CC BY-SA 4.0 Jamie Wood
For several hundred thousand years, about 23 million years ago, the Foulden Maar crater was a lake that slowly filled in with organic materials.
The leaves and dead animals were laid down annually in very thin layers under anoxic conditions, and the researchers have created a year-by-year timeline for the lake which spans more than 100,000 years.
Momentum is gathering to protect Foulden Maar from mining, and former Prime Minister Helen Clark has joined protests being made on online forums such as Twitter.
A pit at Foulden Maar, near Middlemarch. A proposal to mine diatomite would see the entire crater destroyed. Photo: Wikicommons
Our Changing World has previously featured the site and its significant fossils, including its contribution to our understanding of past carbon dioxide levels.
Veronika Meduna visited the mine in 2009 with palaeontologist Daphne Lee, geologist John Lindvqist and botanist Jennifer Bannister.
Jesse Mulligan spoke to University of Otago ancient DNA expert Dr Nic Rawlence about the site’s significance.
Kathryn Ryan spoke to Dr Daphne Lee and Middlemarch resident Andrew Bosshard from Save Foulden Maar on Nine to Noon.
Photo: supplied