mid-ocean ridge
it forms at the mid-ocean ridge, or any at place where there is a gap in the ocean crust and lava flows out.
At the divergent plate margin know as the mid-ocean ridge. At these locations, areas between spreading oceanic plates are infilled with new crust from rising mantle material.
because the older one is more dense and compacted then the new ine
Ocean crust formed, called constructive margins and destroyed, called destructive margins are most offen happening in the ocean.