Beneath the mountainous ocean ridges lies a ribbon-like vat of magma from which tectonic plates are made. The existence of this magma is known from the lavas erupted onto the seafloor and from seismic studies of this region. The eruptive behavior and rate of cooling of this magma is recorded in the numbers and sizes of crystals contained by the lavas. This research involves measuring the distribution of crystal sizes in rocks from the East Pacific Rise and the Mid-Atlantic Ridge to discern the individual styles of magmatism at these ridges. Because the separation rate differs significantly between these ridges, a marked difference in the crystal size distributions is expected. This work will contribute to understanding the fundamental process by which Earth evolves as a planet.