Credit...Michael Frese a virologist and paleontologist at the University of Canberra
The New York Times has a story about an amazing fossil rain forest. Dating to about 15 million years ago during the Miocene Epoch, this deposit hold exquisitely preserved insects, spiders, plans, even a feather. A description of the site was published recently in the journal Science Advances,
Fifteen million years ago, a river carved through the jungle, leaving an oxbow lake (known as a billabong in Australia) in its wake at McGraths Flat. Nearly devoid of oxygen, this stagnant pool kept scavengers at bay, allowing plant material and animal carcasses to accumulate. As iron-rich runoff from nearby basalt mountains seeped into the billabong, the pool’s low pH caused the iron to precipitate and encase the organic material. As a result, the fossils at McGraths Flat are preserved in a dense, iron-rich mineral known as goethite.
This method of fossilization is uncommon, Dr. Hocknull said. Because quality fossils are rarely found in iron deposits, paleontologists often overlook them. However, the fossils from McGraths Flat illustrate that goethite, which is common in Australia, can yield remarkable fossils.
“There’s no shortage of goethite,” Dr. Hocknull said. “We’re essentially a rusting country.”
