Luke Limestone at the top of Mount Tyrwitt overheard the chat between Susan Siltstone and Jimmy Shale at Highwood Pass. He feels intimidated by the siltstone-shale combo. “They must have superpowers to fold up like that. I could never do that. I am too old and stiff.”
Susan giggles. “But somehow you managed to bend your layers a little bit” she yells up the mountain towards him. Luke glances shyly around. His look settles on the little depression in the ridgeline where the shale layers meet the limestone. Today, it’s mostly covered by snow.
“I have nothing to do with the bending of my layers. It was him––Mr. Lewis Thrust fault–– who carried me up to the surface and tilted my layers.” Luke remembers that he used to live a couple kilometers deep down below Earth surface. It was quiet and dark for hundreds of millions of years. But one day, in the Late Cretaceous, everything changed.
“I remember rattling and shaking underneath me. It was scary at first, but later exhilarating when I realized that we all moved.” It was Mr. Lewis Thrust who broke through the rock layers from deep underneath Luke and carried everybody who was on top of him towards the northeast and upwards. Some big force from the southwest was eagerly pushing everything to the northeast. Eventually the thrust fault emerged at the surface. The older rocks that were hanging on the back of Mr. Lewis were pushed on top of the younger rocks below him, squeezing them together.
Luke Limestone knows that his wight and push caused Susan and Jimmy to fold up. “I am sorry that I squeezed you so much. This must have been painful for you.” Susan looks proudly at her curvy layer. Yes – it was painful when it happened, but it was also 72 million years ago. “Don’t worry – we know it wasn’t your fault. It was Mr. Lewis Thrust.” Susan lowers her voice, suddenly being afraid to wake him up. Mr. Lewis has been resting since the Eocene time. Let’s not wake him up!