Obviously the older sedimentary rock is denser because it is much more compacted due to overburden.
New lithosphere is constantly being produced at the oceanic ridges. Lithosphere is consumed at the subduction zones. A balance is maintained because older, denser proportions of oceanic lithosphere descend into the mantle at a rate equal to seafloor production.
It gets younger.
Younger
Younger. The mid-ocean ridge is formed from new material being thrust up from inside the Earth.
Density. Older is usually denser.
The older denser plate subducts
Subduction zones or trenches.
Younger
The subduction process
brachiopods are formed from older brachiopods mating
no
Nextel is the older company out of the two. Nextel was formed 1987 and Verizon was formed 2000.