South America and Africa each have rocks that are about 2.7 billion years old, forming large parts of their continents. The rocks are very hard and contain large crystals due to millions of years of heat and pressure. Rocks that are the same age and type are shown as shaded areas on the maps.
South America
Africa
7. Two students disagree about whether the rocks are igneous or metamorphic. Which statement correctly identifies and describes the rocks?
A The rocks are igneous because they were exposed to heat and pressure for millions of years.
B The rocks are igneous because they are very hard and contain large crystals.
C The rocks are metamorphic because they were exposed to heat and pressure for millions of
years.
D The rocks are metamorphic because they are very hard and contain large crystals.