Stop 6 at Ries

Post-impact crater-fill sediments at Megesheim
Photo: G. Osinski, University of Western Ontario
Location: Megablock zone of the impact structure
Scale: Height of the cliff is 15 meters

Close-up of post-impact crater-lake sediments
Photo: G. Osinski, University of Western Ontario
Location: Megablock zone of the impact structure
Scale: Height of the rock hammer is 35 centimeters

It's not always easy doing fieldwork at the Ries structure! Many of the quarries are completely overgrown by vegetation. At the top of this slope are some more crater-fill sediments. Lets scramble up for a closer look!

Here we can see limestone on top of layered sands and gravels. These limestones are nearly identical to those at the previous stop and were laid down in the post-impact crater-lake. The underlying sands and gravels are part of an ancient delta , sediments that were transported into the crater-lake by a river.

We've now seen crater-fill sediments at 3 locations, including this stop, and from stops 1 and 5 . These sediments allow us to reconstruct the environment after the impact event: rain and groundwater rapidly filled the crater to form a lake; we also know that rivers flowed into and maybe out of the crater-lake. This lake was also soon colonized by blue-green algae and other forms of life, following the devastating impact event.