Question

how does the process that ovcurs at mid-ocean ridges and ocean trenches illustrates the cycling of matter?

Answer 1

This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.

Answer 2

This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary. The other process proposed to contribute to the formation of new oceanic crust at mid-ocean ridges is the "mantle conveyor".