What types of structures form at divergent boundaries? Select the two correct answers. (1 point)
At divergent boundaries, where tectonic plates move apart from each other, two main types of structures typically form:
1. Mid-ocean ridges - Undersea mountain ranges are created by the upwelling of magma from beneath the Earth's crust. As the magma cools and solidifies, new oceanic crust is formed. An example of this is the Mid-Atlantic Ridge, which runs down the center of the Atlantic Ocean.
2. Rift valleys - When divergent boundaries occur within a continent, the stretching and thinning of the Earth's crust can lead to the formation of rift valleys, which are large depressions or troughs bordered by normal faults. An example is the East African Rift system.
These structures are associated with seafloor spreading, earthquakes, and volcanic activity.
what about volcanos
Yes, volcanoes can also form at divergent boundaries. Here’s more detail about volcanic activity in these regions:
Volcanoes at Divergent Boundaries: When tectonic plates move apart, magma from the mantle can rise to fill the gap, because of the reduced pressure. This can lead to frequent volcanic eruptions along the boundary. The lava that erupts is usually basaltic, which is low in viscosity and allows for a steady build-up of new crust.
The mid-ocean ridges are sites of continuous volcanic activity due to the ongoing seafloor spreading process. However, not all of the volcanic activity is explosive; it often involves the extrusion of lava that solidifies to form new oceanic crust.
In continental rift zones, such as the East African Rift, volcanic activity may be more explosive due to the interaction of magma with continental crust and the presence of volatile materials. This can lead to the formation of volcanic features like calderas, cones, and stratovolcanoes.
So, in summary, at divergent boundaries, you can expect to find:
1. Mid-ocean ridges
2. Rift valleys
3. Volcanoes
Both mid-ocean ridges and rift valleys are specific types of structures formed at divergent boundaries, while volcanic activity is a process associated with these structures.
To determine the types of structures that form at divergent boundaries, let's start by understanding what a divergent boundary is. A divergent boundary is a tectonic plate boundary where two plates are moving away from each other. As the plates separate, various geological features arise.
Two correct answers for the types of structures that form at divergent boundaries are:
1. Mid-Ocean Ridges: When two oceanic plates diverge, magma from the mantle rises to fill the gap and creates underwater mountain ranges known as mid-ocean ridges. These ridges can extend for thousands of kilometers and are characterized by volcanic activity, hydrothermal vents, and the formation of new oceanic crust.
2. Rift Valleys: Divergent boundaries can also occur within continents, resulting in the formation of rift valleys. As the continental plates pull apart, the crust stretches and fractures, leading to the creation of long, narrow valleys with steep walls. A well-known example is the East African Rift System, where the African Plate is splitting into two, potentially forming a future ocean.
It's important to note that other features like volcanic activity, earthquakes, and the formation of new crust are associated with divergent boundaries, but the primary structures themselves are mid-ocean ridges and rift valleys.