A team of geologists from Curtin University has made a groundbreaking discovery in the Pilbara region of Western Australia, uncovering evidence of a hypervelocity meteorite impact that occurred 3.47 billion years ago during the Archean Eon. This find is significant because it represents the oldest known crater on Earth, surpassing the previous record holder by nearly 1.2 billion years.
The researchers identified the crater using shatter cones, which are distinctive rock formations formed only under the intense pressure of a meteorite strike. The shatter cones at the site, located about 40 km west of Marble Bar, indicate that a massive impact occurred when a meteorite slammed into the area at speeds of over 36,000 km/h.
This ancient crater is remarkable not only because of its age but also due to its enormous size, estimated to be over 100 km in diameter. The impact would have sent debris flying across the globe, potentially influencing the formation of life on Earth.
The discovery provides a crucial piece of the puzzle of Earth’s impact history and suggests that there may be many other ancient craters waiting to be discovered. According to Professor Chris Kirkland, one of the researchers, “This study sheds new light on how meteorites shaped Earth’s early environment.” The find also has implications for our understanding of crust formation and potentially contributed to the creation of ancient landmasses.
The discovery was published in a paper titled “A Paleoarchaean impact crater in the Pilbara Craton, Western Australia” in the journal Nature Communications.
Source: https://www.sci.news/genetics/archean-impact-crater-13726.html