The rocks that form the new oceanic crust at a mid-ocean ridge are primarily which type?

New oceanic crust at a mid-ocean ridge predominantly consists of igneous rocks. This is because mid-ocean ridges are formed by tectonic activity where tectonic plates are moving apart. As the plates diverge, magma from the mantle rises to fill the gap. When this molten material erupts at the surface of the ocean floor, it cools and solidifies, resulting in the formation of igneous rock, primarily basalt.

This igneous rock is essential for the construction of new oceanic crust, demonstrating the dynamic nature of plate tectonics as well as the process of sea-floor spreading. As it cools quickly in contact with seawater, it forms distinct features like pillow lavas, which are characteristic of undersea volcanic activity. Understanding that mid-ocean ridges are sites of new crust formation helps to clarify why igneous rocks are the primary contributors in these geological settings.