INDIAN GEOGRAPHY

Detailed explanation-1: -Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.

Detailed explanation-2: -Oceanic crust is created as magma rises to fill the gap between diverging tectonic plates and is consumed in subduction zones. It is geologically young, with a mean age of 60 Ma, and is thin, averaging 6.5 km in thickness.

Detailed explanation-3: -As upwelling of magma continues, the plates continue to diverge, a process known as seafloor spreading. Samples collected from the ocean floor show that the age of oceanic crust increases with distance from the spreading centre-important evidence in favour of this process.

Detailed explanation-4: -Magma at the mid-ocean ridge creates new seafloor. As oceanic crust moves away from the ridge crest, it pushes a continent away from the ridge axis. If the oceanic crust reaches a deep sea trench, it sinks into the trench.