sedimentary, wisconsin

Ripple Marks

If you’ve ever looked through clear waters at a beach or gentle flowing river to the sand below, you’ve likely seen ripple marks formed by the moving water. The image above actually shows preserved “fossil” ripple marks in the 1.7 billion-year-old Baraboo (Wisconsin) quartzite. These ripple marks were formed when the marine sandstone was initially deposited… Continue reading Ripple Marks