Continents
Six continents at present time
- North America, South America, Eurasia, Africa, Australia, & Antarctica
Continents possess a wide variety of rock types
- Some rocks originated as rock debris (detritus) or sediment; geologists call these rocks sedimentary rocks
- Some rocks originated by freezing molten silicate liquids; geologists call these rocks either extrusive or intrusive igneous rocks
- Some rocks originated as sedimentary or igneous rocks, but were changed when the ambient temperatures or pressures changed; geologists call these rocks metamorphic rocks