Talk:Limestone Pie and Marble Pie/@comment-26951190-20151031054236/@comment-7345250-20160304203301

Are we really talking about this?

As a matter of fact, it is a fancy transformation because the extreme conditions render the rock's crystal lattice unstable and force the rock to adopt a new crystal structure. This does amount to a change in the chemical composition of the rock, not "just compression."

...And erosion does not make a rock any less metamorphic until the sediments are depositied, compacted, and cemented together over the course of a very, very long time.