Explanation:
it is a geologic time period
If the distance from the ridge increases, the age of rocks also increases.
The exposed portion of the
continental crust underlying North America refers to Canadian Shield. The continental
crust is known as the North American Craton which consists of rocks from the
Archean dn Proterozoic eons and extends from Mexico to Greenland. Canadian
Shield also produces great resources that helped most humans for their economic
development. Because of the resources present in the Shield, it has a great
disadvantage to settlers. The primary obstacle to population growth in the area
is the presence of the bare rock, thin soils, muskeg and insects.
Answer:
crust lower mantle and upper mantle
Explanation:
