Geology of the Rocky Mountains Japan, Indonesia and the Aleutians; others are fragments of oceanic crust obducted onto the continental margin while others represent small isolated mid-oceanic islands. Magma generated above the subducting slab rose into the North American continental crust about inland. Great arc-shaped volcanic mountain ranges, known as the Sierran Arc, grew as lava and ash spewed out of dozens of individual volcanoes. Beneath the surface, great masses of molten rock were injected and hardened in place. For 270 million years, the effects of plate collisions were focused very near the edge of the North American plate boundary, far to the west of
Journey to the Center of the Earth Journey to the Center of the Earth Journey to the Center of the Earth (, also translated under the titles A Journey to the Centre of the Earth and A Journey to the Interior of the Earth) is an 1864 science fiction novel by Jules Verne. The story involves German professor Otto Lidenbrock who believes there are volcanic tubes going toward the centre of the Earth. He, his nephew Axel, and their guide Hans descend into the Icelandic volcano Snæfellsjökull, encountering many adventures, including prehistoric animals and natural hazards, before eventually coming to the surface again in southern Italy, at