Scientists say they have discovered the largest impact crater in the planet’s history, deeply buried under bedrock in central Australia. The discovery — known as the Massive Australian Precambrian-Cambrian Impact Structure (MAPCIS) — should shed light on these processesorld-forming the dynamics of our planet.
The Colossal Crater
Others picture a crater big enough to swallow the entire state of New South Wales. It is the size of MAPCIS, which covers a region spanning 600 kilometers (370 miles) or more.
In a study by Daniel Connelly and Arif Sikder of Virginia Commonwealth University, researchers have found convincing proof that such a non-concentric complex crater exists. Their findings could reshape understanding of the planet’s geological history and suggest there are many more “undiscovered” minerals locked up in the rock record.
The enormity and location of this crater is just amazing, Deep in the heart of Australia lies a massive impact structure that may finally reveal what kinds of forces marked our planet for over 4 billion years. It’s a sobering reminder of the colossal — and often capricious — power exerted through millions of years in the geological processes that have created our planet.
Breaking Down the Geological Evidence
They have amassed a rich geological record of evidence that attests to the MAPCIS’s existence and importance. The examination reveals that in the center of the crater lie huge deposits of pseudotachylite breccia–or melt rock. The rock, known as suevite, can only be created in the event of such a collision; thought to form when a meteorite or an asteroid impact melts rocks around it and forms hot liquid on the bench before it cools immediately.
The researchers have also found shocked minerals, such as lonsdaleite (or another type of shocked diamond) in these deposits. Such Lonsdaleite is a incredibly rare mineral that you can find only when meteors hits the earth and provide additional evidence in favor of the MAPCIS.
They have also discovered higher concentrations of iridium, a rare metal that is commonly linked to meteorite impacts, in the layers around their new crater. Such a geochemical signature is in keeping with the Cretaceous-Paleogene (K-T) extinction event, the mass extinction which saw an asteroid impact wipe out the dinosaurs 66 million years ago.
If the MAPCIS could be dated reliably to the end of the Ediacaran period, a time in Earth’s history just before widespread animal diversification (from about 1 billion to 538.8 million years ago) then this impact event perhaps led to profound changes in both geology and biology on a planetary scale during such a critical juncture for life.
Conclusion
The finding of the MAPCIS represents a huge discovery that could easily change what we know about Earth’s geological history. Buried in the heart of Australia, this huge crater reveals fresh answers to the brutal forces that shaped our Earth over countless eons. New findings to be learned as geologists further investigate this astonishing geological feature and tap deeper into the inescapable tale of our dynamic planet, the Earth.
