Which is responsible for the formation of mid ocean ridges
Magma rising from the Earth's mantle is responsible for the formation of mid ocean ridges.
The formation of mid-ocean ridges is primarily due to a geological process called seafloor spreading. Here are the step-by-step processes involved:
1. Tectonic Plate Movement: The Earth's lithosphere is divided into several large plates that float and move on the semi-fluid asthenosphere below. Mid-ocean ridges are formed at constructive plate boundaries, where two tectonic plates are moving apart.
2. Upwelling Mantle Material: As the plates move apart, magma from the Earth's mantle rises to fill the gap, forming a magma chamber beneath the seafloor.
3. Magma Intrusion: The rising magma intrudes into the overlying crust through fractures and cracks, forming a network of dikes.
4. Magma Solidification: When the magma is exposed to the cold seawater, it cools and solidifies, forming new oceanic crust.
5. Seafloor Spreading: The solidified magma pushes the adjacent crust aside, causing it to crack and fracture along the ridge axis. The new crust is continually pushed away from the ridge, creating a widening gap that is filled with fresh magma.
6. Faulting and Earthquakes: The movement of the plates and the formation of new crust can cause seismic activity and earthquakes along the mid-ocean ridge.
7. Subsequent Processes: Over time, as the newly formed crust moves away from the ridge axis, it cools and contracts. This causes it to become denser and sink lower into the asthenosphere. As a result, the oceanic lithosphere becomes older and more heavily sedimented, forming a distinctive pattern of symmetrical magnetic stripes parallel to the ridge.
Overall, the continuous process of seafloor spreading at mid-ocean ridges contributes to the gradual expansion of the ocean basin and the formation of new oceanic crust.