Want this question answered?
earths crust includes ocean floors and
seismograph
A the answer is hydrogen
it has been washed into the oceans as the continental crust has eroded.
Oceanic crust, new oceanic crust is produced by seafloor spreading.
The surface.
Fault
From lithospheric interactions with the asthenosphere.
Earths crust extend deeper below the continents than below the oceans basins (or at least this is what I think).
Butt face
earths crust , oceans and atmosphere
You can say that it is low in silica. -I had this problem in my science class ^_^