Some of the physiographic features that cause extreme aridity may be found together within a <span>single desert, but t</span>he deserts found in the western united states are primarily the result of being located within the rain shadow of one or more mountain ranges.
The Rocky Mountains are described as younger because the Rocky's are really two mountain chains. The older mountain chain started billions of years ago, and the younger mountain chain pushed the older mountain chain up more, only 60 millions years ago.
Abyssal Plain I think. Sorry if it’s wrong.
It would be a problem because it would cause the land in Mexico City to sink.
