this crack in the ground suddenly appeared in the foothills of the Bighorn Mountains in Wyoming. How did it come about? Nobody is saying for sure but a spokesman commented, it just goes to show how quickly some geological events can occur.
Presumably some kind of subsidence was involved but it does make you wonder how it would have been dated if humans had not been around – a process taking place over a long period of time. Go to www.mnn.com/earth-matters/wilderness-resources/stories/massive-crack-ear…
it looks almost like a ravine, one of those gullies carved out by a thunderbolt (?) or by water erosion – yet it was formed within a fortnight (between visits to the area) and in all likelihood happened almost at once. How do you explain something like that? Well, an engineer provides an opinion at the link above. A wet spring lubricated across a cap rock. Then, a small spring on either side caused the bottom to slide out (and you thought solid rock was stable).