I hope it wasn't a platonic uplift, I've had too many relationships like that. :D Actually, it might be a plutonic uplift, cxcept they usually don't go in such perfect circles. The Rocky Mtns. are an example of uncovered batholiths, wannabe volcanoes that stopped at depth, and were caused by plutonic activity. Personally, I think it looks like the world's biggest flying saucer finding. (Grin)
Oh, the dangers of relying on spellcheck! ;^)