ancients earth planet with supercontinents laurasia and gondwana

age ancient antique baltica china continent continental continents disaster drift earth earthquake era euramerica formation geography geological geology gondwana historical history kazakhstania laurasia laurentia laurussia magma mass mesozoic neoproterozoic north ocean origin paleozoic panagea pangaea panthalassa planet precambrian science sea siberia south space supercontinent superocean tarim theory tsunami view wegener world