The movement of the plates creates three types of tectonic boundaries: convergent ... On land, giant troughs such as the Great Rift Valley in Africa form where plates are tugged apart.

Earth's five oceans were formed by the constant movement of tectonic plates beneath us, and the same process is already ...

The shallow waters of the rift valley can be ideal environments for limestones to form. Here is a nice summary of sedimentation on divergent margins: be sure to look at the diagrams ... New ocean ...