Rocks similar to those we can see in the Grand Canyon (above) have been found in Tasmania, suggesting that the island south of Australia was once adjacent to the western United States. Image credit: Grand Canyon National Park Service; photo by W. Tyson Joye

Over 13,000 km (8000 miles) separate Arizona from Tasmania today, but a geologic study of Tasmanian rocks comes to the conclusion that the island south of Australia was once close to the Grand Canyon. Similar stratigraphy and depositional ages (1.25-1.1 billion years) establish a correlation between rock units in Tasmania and the Grand Canyon, suggesting that Tasmania must have been attached to the western United States. Finding a link between modern-day Australia and the western coast of North America provides useful information about the formation history of the supercontinent Rodinia, which existed between 1.1 billion and 750 million years ago, comprising most of Earth’s landmass before it broke up again. READ MORE