Question: How deep is it possible for a volcano to go into the Earth?

Matthew Pankhurst answered on 21 Jun 2013:

Some liquid rock that makes volcanoes can come from deeper than 200 km into the earth! These are special volcanoes called “kimberlites” and on their way up and out the bring diamonds to the surface 🙂 That’s about the limit we think – maybe 300 km, but we’re always finding out more about where they come from!