Seafloor spreading is defined as:

Seafloor spreading is defined as:

• A. The creation of oceanic crust at subduction zones
• B. The melting of crust at ridges
• C. The process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge
• D. The breaking of continents into smaller landmasses

Answer: (C)

Seafloor spreading is the process by which new oceanic crust forms along mid-ocean ridges and older oceanic crust moves away from the ridge. At divergent plate boundaries, magma from the mantle rises at the ridge, erupts as lava, and cools to create new basaltic crust. As more magma continues to rise, the newly formed crust is pushed outward from the ridge by mantle convection, causing the seafloor to spread. This pattern is supported by magnetic stripes in the cooled rocks that mirror on opposite sides of the ridge, showing reversals of Earth's magnetic field over time. Over long timescales, oceanic crust is added at ridges and recycled back into the mantle at subduction zones, driving plate tectonics. The other descriptions don’t fit: crust isn’t created at subduction zones (those areas recycle crust), ridges aren’t sites of crust melting, and continental breaking describes continental rifting rather than the formation and outward move of oceanic crust.

Seafloor spreading is the process by which new oceanic crust forms along mid-ocean ridges and older oceanic crust moves away from the ridge. At divergent plate boundaries, magma from the mantle rises at the ridge, erupts as lava, and cools to create new basaltic crust. As more magma continues to rise, the newly formed crust is pushed outward from the ridge by mantle convection, causing the seafloor to spread. This pattern is supported by magnetic stripes in the cooled rocks that mirror on opposite sides of the ridge, showing reversals of Earth's magnetic field over time. Over long timescales, oceanic crust is added at ridges and recycled back into the mantle at subduction zones, driving plate tectonics. The other descriptions don’t fit: crust isn’t created at subduction zones (those areas recycle crust), ridges aren’t sites of crust melting, and continental breaking describes continental rifting rather than the formation and outward move of oceanic crust.