Because the crust being formed pushes old crust under other plates or crust
<span>I believe its called, tributaries</span>
The answer that is being described above is SPAIN. This is the country that sent explorers so they can take control of the lands in the south and west of Mississippi river because of the gold deposits, as well as farming and ranching. Hope this answers your question.
Economic Reconstruction
Hope this helps and if it does give me a thanks :)
