GEOLOGY

Detailed explanation-1: -At an ocean-ocean convergent boundary, one of the plates (oceanic crust and lithospheric mantle) is pushed, or subducted, under the other. Often it is the older and colder plate that is denser and subducts beneath the younger and hotter plate. There is commonly an ocean trench along the boundary.

Detailed explanation-2: -When two oceanic lithospheres collide, one runs over the other which causes the latter to sink into the mantle along a zone called a subduction zone. The subducting lithosphere is bent downward to form a very deep depression in the ocean floor called a trench. The deepest ocean in the world is found along trenches.

Detailed explanation-3: -At a convergent boundary between two plates of oceanic lithosphere, the older, denser oceanic plate will always subduct, which will cause earthquakes and form volcanic isles.

Detailed explanation-4: -intraoceanic arcs (primitive arcs) form when oceanic crust subducts beneath other oceanic crust on an adjacent plate, creating a volcanic island arc. continental arcs form when oceanic crust subducts beneath continental crust on an adjacent plate, creating an arc-shaped mountain belt.

Detailed explanation-5: -When two oceanic plates converge, the cooler, denser one descends, or subducts, beneath the overriding plate and sinks into the mantle. When an oceanic plate meets a plate with a continent riding atop it, the oceanic plate is again subducted.