It's #TravelTuesday and #ASUEverywhere is taking you on a virtual field trip to Karijini National Park, the second largest national park in Western Australia. It's home to rocks as old as 2 billion years. 💧 At Fortescue Falls, bands of iron trace the walls for tens to hundreds of kilometers. They tell the story of a deep, calm ocean that was very different from any ocean today. 🔴 These layers of red iron and white silica could only be created by a once iron-rich ocean. If you look closely, the pattern continues in layers as small as millimeters and even microscopic. 👀 The finely layered rocks are so large that their edges have never been found. Their enormity suggests there was once a very large body of water where they now stand. ⚫️ Hidden far beneath the weathered surface of these rocks is shiny black pyrite speckled with what's known as Fool's Gold. The percentage of carbon in this pyrite is so high, it's considered a biosignature for oceanic life 2 billion years ago. �...