GEOLOGY

Detailed explanation-1: -Oceanic crust is constantly formed at mid-ocean ridges, where tectonic plates are tearing apart from each other. As magma that wells up from these rifts in Earth’s surface cools, it becomes young oceanic crust. The age and density of oceanic crust increases with distance from mid-ocean ridges.

Detailed explanation-2: -The depth of the seafloor on the flanks of a mid-ocean ridge is determined mainly by the age of the oceanic lithosphere; older seafloor is deeper. During seafloor spreading, lithosphere and mantle cooling, contraction, and isostatic adjustment with age cause seafloor deepening.

Detailed explanation-3: -The newest, thinnest crust on Earth is located near the center of mid-ocean ridge-the actual site of seafloor spreading. The age, density, and thickness of oceanic crust increases with distance from the mid-ocean ridge.

Detailed explanation-4: -The age of oceanic crust can be determined by analyzing the mineralogy of the rock and how it compares to other rocks found on the Earth’s surface. The age of ocean floor features can be determined by analyzing the fossils that are found on or near these objects.

Detailed explanation-5: -The oldest oceanic crust is about 200 million years old. The average age of continental crust is about 2 billion years old.