We've got some accreted terrane going on but most of our geology is focused on the OMG HUGE PLATE BOUNDARY running through the country ... hence my first thought on those mountains being back-arc volcanism!

I know right? And the enormous batholith to the north is GOING to cause some contact met, for which I think I'm going to have to subtly question my best mate (he's a met-pet/economic geo student) because sadly I slept through most of my met classes. Whoops!