Ripples

Now, this is what I call REALLY interesting! This is a sandstone from Greenland, about 1,500 million years old. The red colour is oxidised iron and the ripple marks are the patterns of water lapping over sand on a beach. Yes, just like the ripples that you get on the sand of a modern beach, only this sand was buried and, eventually, turned into stone. The ripple marks are preserved because the sand was gently buried by more sand and protected from erosion. The piece of rock is about 10cm x 6.5cm. In some areas near this there are also the small pits of raindrops hitting the mud surface - raindrop holes from 1,500 million years ago, now that is cool!