Answer:
At convergent boundaries :
- subduction
- magma breaks through the crust
- island arc
- volcanic mountains
At divergent bounderies :
- rift valleys
- magma flows from cracks
- mid-ocean ridges
- plates pulling apart
Your answer is Puerto Rico for sure
The main difference between the thickness and density of earths crust and mantle is the material making up each section. temperature and function also differ between the two sections
