Magma is the molten material beneath the Earth's crust. It usually collects in a magma chamber beneath a volcano, and can then be injected into cracks in rocks or issue out of volcanoes in eruptions.
In A Nutshell Mars was erupting while T. rex roamed Earth: A Martian volcano system was active between 64 and 50 million years ago, overlapping with the age of dinosaurs and early mammals on our ...