When tectonic plates pull apart from one another, the process is known as divergent tectonics. In this setting, tensional stress is exerted on the rocks, which can lead to the formation of faults. A fault is a fracture or zone of fractures between two blocks of rock, allowing them to move relative to each other.
One of the most notable types of faults formed in these environments is the normal fault. In a normal fault, the hanging wall moves downward relative to the footwall, which is characteristic of areas experiencing extension due to the pulling apart of tectonic plates.
As the tectonic plates continue to separate, features such as rift valleys or mid-ocean ridges may develop, depending on whether the divergence occurs on land or under the ocean. In rift valleys, the crust can thin and fracture, creating new geological features. In oceanic settings, divergent boundaries can lead to the formation of new oceanic crust as magma rises from the mantle to fill the gap created by the separating plates.
In summary, the pulling apart of tectonic plates results in tensional stress, leading to the formation of normal faults and contributing to significant geological features caused by the movement and interaction of the Earth's lithosphere.