* Seafloor Spreading: At mid-ocean ridges, new oceanic crust is created through volcanic activity. This process pushes older crust away from the ridge, creating a "conveyor belt" effect.
* Age Gradient: As you move further from the ridge, you're essentially traveling back in time. The crust further away from the ridge is older because it was formed earlier in the spreading process.
* Sedimentation: As the seafloor ages, it also accumulates more sediment. This sediment can be derived from rivers, windblown dust, and biological processes. The thickness of these sediment layers also generally increases with distance from the ridge.
In summary: The age of seafloor sediments increases with distance from ocean ridges because the process of seafloor spreading constantly pushes older crust further away from the point of its creation.
