Hey Civ; seems there was an article/thread posted last year wherein someone theorized that large chunks of subducted crust, or maybe even chunks of mantle 'more solid than yer average blob of mantle' were prone to being thrust upward and thereby, in very short order, create mountains or mountain ranges. Time frames on the order of days or weeks instead of centuries or millennia. I found it interesting since I'm not automatically inclined to accept the uniformitarianism/gradualism theories at face value any way.
When you get a free minute or two, might you be able to run it down?