What forms at divergent boundaries?
At divergent boundaries, several geologic features can form:
1. Mid-Ocean Ridges: Underwater mountain ranges that form at divergent boundaries in the ocean. As the tectonic plates move apart, hot mantle material rises to fill the gap, creating new crust. This process forms a continuous ridge in the middle of the ocean.
2. Rift Valleys: On land, divergent boundaries can create rift valleys. As the tectonic plates pull apart, the crust weakens and breaks, leading to the formation of a linear valley. Rift valleys are characterized by steep walls and can eventually evolve into new ocean basins if the splitting continues.
3. Fissure Volcanoes: Along divergent boundaries, magma can rise to the surface through long cracks in the crust called fissures. This magma erupts as lava and forms volcanic features known as fissure volcanoes. These volcanoes typically have elongated shapes with low profiles.
4. Faults: Divergent boundaries are also associated with normal faults. Normal faults occur when the crust is pulled apart and one block of rock moves downward relative to the other. These faults can create visible fractures or rifts in the Earth's surface.