These pillow buds from the East Pacific Rise formed when the magmatic pressure within a pillow caused tiny fractures through which magma seeped. The preservation of the fragile protuberances of chilled magma is evidence that the rocks are relatively young.
Provided by Prof. John Edmond, Woods Hole Oceanographic Institution
Topic: Earth Science
Keywords: Lava, Magmas, Mid-ocean ridges, Ocean bottom, Volcanic eruptions, Volcanoes