africa afro-eurasia americas angola antarctica arctica asia asiamerica atlantica atlantis avalonia baltica bangweulu block cameroon central african republic continent craton democratic republic of the congo diamictite earth euramerica eurasia europe gabon geology glacier gondwana kaapvaal craton kalahari craton kazakhstania kenorland kerguelen plateau laurasia laurentia limestone list of supercontinents neoproterozoic oceania pangaea pangaea ultima pannotia precambrian rodinia shale sudan supercontinent terra australis united states vaalbara zambia zimbabwe craton