What geologic process is common to the formation of mountains in a divergent boundary and in a hot spot?
The geologic process common to the formation of mountains in a divergent boundary and a hot spot is volcanic activity.
To understand why, let's break it down:
1. Divergent Boundary: This occurs when two tectonic plates are moving away from each other. As they separate, a gap or rift forms between them. Magma rises from the mantle into this gap, filling it and creating new crust. This process is termed "seafloor spreading." Over time, as new crust is continuously formed, it pushes the existing older crust away from the rift zone, causing it to crack and fracture. This fracturing, along with the accumulation of lava and volcanic material, leads to the formation of mountains along the divergent boundary.
2. Hot Spot: A hot spot is an area of intense volcanic activity that occurs beneath the Earth's surface, usually within a tectonic plate. It is characterized by a stationary plume of hot mantle material rising up from deep within the mantle. As the tectonic plate moves over this stationary hot spot, volcanoes are formed. Over time, the repeated eruptions of lava build up and create mountains.
In both cases, volcanic activity plays a crucial role in the formation of mountains. The key difference is that in a divergent boundary, the mountains are formed as a result of the movement of tectonic plates and seafloor spreading, while in a hot spot, the mountains are formed due to the stationary plume of hot mantle material underneath a tectonic plate.