New answers tagged

-1

The simplified answer is that most volcanoes occur where the crust is thin. This allows magma from the Earth's upper mantle to rise and create trouble. Most active volcanos are found at the bottom of the sea where plates are spreading! We just had one erupt near Tonga. Many island chains are made from volcanic activity. Plates that collide make ...


10

Or is the continental crust too dry? Exactly this. Continental collision zones are actually full of volcanic rocks, which formed at the time before it was a continental collision zone. The Wikipedia article on the Geology of the Himalaya has a nice summary of the suture zone: "Dras Volcanics": are relicts of a "Late Cretaceous" to "...


3

Two major reasons, crustal thickening and thermochemical interactions. Heat plumes, whether from crustal recycling or the deep mantle, can only melt through so much rock before they lose heat and either convect away or freeze on/in to the rock they have penetrated as intrusive deposits. Crustal thickening as rock piles up at convergent margins means that ...


Top 50 recent answers are included