propagating rift

A propagating rift is a geological feature where one segment of a spreading center, typically at a divergent plate boundary, grows at the expense of another segment across a transform fault. This process involves the lengthening of a rift, which is a crack or series of cracks in the Earth's crust.12

These rifts are often associated with normal faults, where the block of rock above the fault moves downward relative to the block below due to extension. This can lead to the formation of rift valleys, which are tectonic valleys that can be thousands of meters deep. Examples include the East African Rift System and valleys found along oceanic ridges where new crust is formed through seafloor spreading. The movement of tectonic plates, driven by forces within the Earth's mantle, is the fundamental cause of these rifting processes.213