FACOG stands for âFellow, American College of Obstetricians and Gynecologists.â ACOG is the nationâs leading group of professionals providing health care for women. For more information, go to the American College of Obstetricians and Gynecologists.
Age of oceanic crust; youngest (red) is along spreading centers. Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.Seafloor spreading helps explain continental drift in the theory of plate tectonics.he destruction of oceanic crust occurs at subduction zones where oceanic crust is forced under either continental crust or oceanic crust. Today, the Atlantic basin is actively spreading at the Mid-Atlantic Ridge. Only a small portion of the oceanic crust produced in the Atlantic is subducted.
As the tectonic plates move apart, rock is pulled up from depth at the spreading axis and melts as it depressurizes. The molten rock rises to the seafloor and cools to form the layer of crust that paves the ocean floor. Fig. 5. Seafloor spreading at the Mid-Atlantic Ridge. Basemap adapted from image on Structural Geology and Tectonics website at Duke University, http://www.geo.duke.edu/Research/struct/MAR.html.