Feature Ring: A Geological Deep Dive

The Deniliquin multiple-ring feature is a deeply buried structure in southeast Australia, named after the nearby town of Deniliquin. Its characteristics suggest it is an asteroid impact structure with a diameter of 520 km, which would make it the largest on Earth, surpassing the Vredefort impact structure.

First proposed by Anthony Yeates between 1995 and 2000 based on magnetic patterns, the feature lies beneath the Murray and Darling sedimentary basins. A 2022 paper by Glikson and Yeates further supports the impact hypothesis using geophysical data and drill samples. The structure features a multiple-ring magnetic pattern, a central quiet magnetic zone, and radial faults.

If confirmed, the impact may have triggered the Late Ordovician glaciation and mass extinction event around 445 million years ago, which eliminated about 85% of species. Further deep drilling is needed for definitive confirmation.