An example of folding of Miocene sediments, producing a syncline over which later Quaternary sediments have been deposited. From the Mojave Desert, California.
But where does this term 'palimpsest' come from and what does it mean? A palimpsest comes for the Greek for 'scraped again' and is used by historians to refer to manuscripts (often written on parchment or vellum) which have been rubbed out and new texts written over the top. Often this process has been repeated many times. A good example, which forms the basis of an exhibition at the Walters Art Museum can be found described and illustrated at: