In his second post at Earth Science Erratics Simon Wellings reveals a rather interesting deskcrop, collected from Scotland in his youth:
Since it was picked up, this rock has changed identities: what was once thought to be a mud flow deposit is now thought to be formed from the debris of an ancient meteorite impact! What’s the evidence for this radical interpretation? Can we tell anything about the impact that formed this chunk of rock? Find out in Simon’s post.