Why, in the Mythen Peaks of the alps, do Triassic rocks 200 million years old rest on Eocene rocks?

Question

The Triassic layer is above the Eocene layer even though it is 150 million years older!

Why has that happened?

Answer 1

The beds have been overturned.  The Alps are an especially tortured mountain range so you can expect to see 'anomalies.'  Overturned beds are not all that rare and occur around the world.

The missing beds are probably due to lack of original deposition during a stage when the Jurrasic beds were high in the mountains but before overturning.  In some areas the missing beds are due to erosion.