What two pieces of information would researchers need to have in order to calculate the rate of plate motion for seafloor spreading?

-Distance from the rift and age of seafloor sample

-Type of rock and distance from the rift

-Age of the continent and depth of the water

-Age of the seafloor sample and age of the continent

Distance from the rift and age of seafloor sample

Explanation:

The seafloor spreading occurs along the mid-oceanic ridges and here the new crust is formed and thus moves gradually away from the ridge. The spreading can be determined by the age of the rocks and the age of the seafloor and the type of the rock associated with the distance from the rift.