"time scales lasting hundreds of millions of years, the supercontinents have formed and broken apart three times. Roughly (million years ago), one of the earliest known supercontinents, Rodinia, began to break apart. The continents later recombined to form Pannotia, 600–, then finally Pangaea, which also broke apart . ""Land mass"" refers to the total surface area of the land of a geographical region or country (which may include discontinuous pieces of land such as islands). It is written as two words to distinguish it from the usage ""landmass"", the contiguous area of land surrounded by ocean. Earth's total land mass"
"area—it is also used as two words. Landmasses include supercontinents, continents, and islands. There are four major continuous landmasses on Earth: Afro-Eurasia, the Americas, Antarctica and Australia. Land, capable of being ploughed and used to grow crops, is called arable land. A country or region may be referred to as the motherland, fatherland, or homeland of its people. Many countries and other places have names incorporating -land (e.g. New Zealand). The earliest material found in the Solar System is dated to (billion years ago); therefore, the Earth itself must have been formed by accretion around this time. By , the"
"Earth, land""). The concept that the continents once formed a continuous land mass was first proposed by Alfred Wegener, the originator of the scientific theory of continental drift, in his 1912 publication ""The Origin of Continents"" (""Die Entstehung der Kontinente""). He expanded upon his hypothesis in his 1915 book ""The Origin of Continents and Oceans"" (""Die Entstehung der Kontinente und Ozeane""), in which he postulated that, before breaking up and drifting to their present locations, all the continents had formed a single supercontinent that he called the """"Urkontinent"""". The name ""Pangea"" occurs in the 1920 edition of ""Die Entstehung der"
"helped prevent the atmosphere from being stripped away by the solar wind. A crust formed when the molten outer layer of Earth cooled to form a solid. The two models that explain land mass propose either a steady growth to the present-day forms or, more likely, a rapid growth early in Earth history followed by a long-term steady continental area. Continents formed by plate tectonics, a process ultimately driven by the continuous loss of heat from Earth's interior. Over the period of hundreds of millions of years, the supercontinents have assembled and broken apart. Roughly (Mya), one of the earliest"
"the molten outer layer of the planet Earth cooled to form a solid mass as the accumulated water vapor began to act in the atmosphere. Once land became capable of supporting life, biodiversity evolved over hundreds of million years, expanding continually except when punctuated by mass extinctions. The two models that explain land mass propose either a steady growth to the present-day forms or, more likely, a rapid growth early in Earth history followed by a long-term steady continental area. Continents formed by plate tectonics, a process ultimately driven by the continuous loss of heat from the Earth's interior. On"
"through the Eurasian subtropical zone from the Atlantic to the Pacific. This belt became the mainstream of world history for two millennia. Originally, “Eurasia” is a geographical notion: in this sense, it is not the biggest continent but the combined landmass of Europe and Asia in order to be known as the biggest to exceed Africa. Very much like a tall man measured to a short man but the short man adds 4 other men to become taller. However, geopolitically, the word has several different meanings, reflecting the specific geopolitical interests of each nation. “Eurasia” is one of the most"
"continental crust. It makes up about 70% of the volume of Earth's crust. Because the surface of continental crust mainly lies above sea level, its existence allowed land life to evolve from marine life. Its existence also provides broad expanses of shallow water known as epeiric seas and continental shelves where complex metazoan life could become established during early Paleozoic time, in what is now called the Cambrian explosion. All continental crust ultimately derives from the fractional differentiation of oceanic crust over many millions of years. This process has occurred, and continues to occur today, primarily as a result of"
"New World The New World is one of the names used for the majority of Earth's Western Hemisphere, specifically the Americas (including nearby islands such as those of the Caribbean and Bermuda). The term originated in the early 16th century after Europeans made landfall in what would later be called the Americas in the age of discovery, expanding the geographical horizon of classical geographers, who had thought of the world as consisting of Africa, Europe, and Asia, collectively now referred to as the Old World (a.k.a. Afro-Eurasia). The phrase gained prominence after the publication of a pamphlet titled ""Mundus Novus"""
"formed. The eastern part of this ocean formed between Baltica and Laurentia, the western part between Amazonia and Laurentia. Because the exact moments of this separation and the partially contemporaneous Pan-African orogeny are hard to correlate, it might be that all continental mass was again joined in one supercontinent between roughly 600 and 550 million years ago. This hypothetical supercontinent is called Pannotia. Unlike later supercontinents, Rodinia would have been entirely barren. Rodinia existed before complex life colonized dry land. Based on sedimentary rock analysis Rodinia's formation happened when the ozone layer was not as extensive as it is today."
"the middle of a giant continent called Pangaea. This supercontinent began to fracture 220 million years ago when the Earth's lithosphere was being pulled apart from extensional stress, creating a divergent plate boundary known as the Fundy Basin. The focus of the rifting began somewhere between where present-day eastern North America and northwestern Africa were joined. During the formation of the Fundy Basin, volcanic activity never stopped as shown by the going eruption of lava along the Mid-Atlantic Ridge; an underwater volcanic mountain range in the Atlantic Ocean formed as a result of continuous seafloor spreading between eastern North America"
"plate, a small continent which broke up from Africa before the Alpine orogeny. For this reason the Matterhorn has been popularized as an African mountain. The Austroalpine nappes are mostly common in the Eastern Alps. The Swiss explorer and geologist Horace-Bénédict de Saussure, inspired by the view of the Matterhorn, anticipated the modern theories of geology: The formation of the Matterhorn (and the whole Alpine range) started with the break-up of the Pangaea continent 200 million years ago into Laurasia (containing Europe) and Gondwana (containing Africa). While the rocks constituting the nearby Monte Rosa remained in Laurasia, the rocks constituting"
"rock, represent sutures between the protocontinents. The Earth's continents started to form in the Archean, although details about their formation are still being debated, due to lack of extensive geological evidence. One hypothesis is that rocks that are now in India, western Australia, and southern Africa formed a continent called Ur as of 3,100 Ma. A differing conflicting hypothesis is that rocks from western Australia and southern Africa were assembled in a continent called Vaalbara as far back as 3,600 Ma. Although the first continents formed during this eon, rock of this age makes up only 7% of the present"
"earth. Beginning with Europe at the top, to the right is Asia, Africa and Australia, the great land masses of the Old or Eastern World. To the left on the key is North America, South America, and Antarctica, the three great land masses brought into geographical knowledge as man expanded westward from Europe, the so-called New World. Spread across the base of the key are five wavy blue lines, significant of the five great bodies of water which have carried man out from Europe to the lands of the earth, -the Atlantic Ocean, the Indian Ocean, the Pacific Ocean, the"
"Continent A continent is one of several very large landmasses of the world. Generally identified by convention rather than any strict criteria, up to seven regions are commonly regarded as continents. Ordered from largest in area to smallest, they are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia. Geologically, the continents largely correspond to areas of continental crust that are found on the continental plates. However, some areas of continental crust are regions covered with water not usually included in the list of continents. Zealandia is one such area (see submerged continents below). Islands are frequently grouped with"
"the product of a complex history stretching back half a billion years. Its most ancient mountains, the Caledonites and Urals, were formed during the collision of continental plates from which modern Europe is assembled, described as ""the first act of European union"". During the Carboniferous period, Europe's equatorial jungles harboured giant predatory invertebrates, and the landmarks of Paris, Frankfurt and Berlin would have stood amid unbroken primeval forests. By 270 million years ago, Europe had drifted north and become part of the supercontinent Pangaea. The forests of the interior, cut off from life-giving rains, turned to desert, their remains forming"
"was occurring in the Proterozoic Eon. As a result of remelting of basaltic oceanic crust due to subduction, the cores of the first continents grew large enough to withstand the crustal recycling processes. The long-term tectonic stability of those cratons is why we find continental crust ranging up to a few billion years in age. It is believed that 43% of modern continental crust was formed in the Proterozoic, 39% formed in the Archean, and only 18% in the Phanerozoic. Studies by Condie 2000 and Rino et al. 2004 suggest that crust production happened episodically. By isotopically calculating the ages"
"that early ""Homo sapiens"" dispersed around the continent and elements of human modernity appeared in different places, and so different parts of Africa contributed to the emergence of what we call modern humans today."" Early humans may have comprised a large, interbreeding population dispersed across Africa whose spread was facilitated by a wetter climate that created a ""green Sahara"", around 300,000 to 330,000 years ago. The rise of modern humans may thus have taken place on a continental scale rather than being confined to a particular corner of Africa. In 2005, the World Atlas of Language Structures, a project of"
"the continents, shallow sea deposits (limestones) were formed during the entire Mesozoic. In the late Jurassic the microcontinent Iberia broke away from the European plate and the Valais Ocean was formed between the two plates. Both Piemont-Liguria and Valais Oceans were never large oceans such as today’s Atlantic Ocean. What they might have been like is the opening below the Red Sea, continuing down through Africa, forming the Great Rift Valley. Eventually, a new ocean will cut through east Africa as the rift develops, dividing a large section of land from the main continent. When at the end of the"
"on the equator and reached from 60° N to 60° S. 1.2-1 bya to 800-850 mya, Proterozoic Eon - end of Precambrian. It was the first supercontinent to form on Earth, all the continental crust on Earth came together and formed one giant land mass. This land mass was surrounded by an even larger ocean, known as Mirovia. There were about four smaller continents that collided and came together to form Rodinia. This event is called the Grenville Orogeny. This caused there to be mountain building along the areas of were continents collided. This is because the continental crust is"
"bigger. Grass started to expand in the Miocene, and the Miocene is where many modern- day mammals first appeared. Giant ungulates like ""Paraceratherium"" and ""Deinotherium"" evolved to rule the grasslands. The evolution of grass also brought primates down from the trees, and started human evolution. The first big cats evolved during this time as well. The Tethys Sea was closed off by the collision of Africa and Europe. The formation of Panama was perhaps the most important geological event to occur in the last 60 million years. Atlantic and Pacific currents were closed off from each other, which caused the"
"Afro-Eurasia Afro-Eurasia (or Afroeurasia, or Eurafrasia, or nicknamed the World Island) is a landmass which comprises the continents of Eurasia (Europe and Asia) and Africa. The terms are portmanteaus of the names of its constituent parts. It is the largest contiguous landmass on Earth. Afro-Eurasia encompasses , a little over half the world's land area, and has a population of approximately 6 billion people, roughly 86% of the world population. The following terms are used for similar concepts: Although Afro-Eurasia is typically considered to comprise two or three separate continents, it is not a proper supercontinent. Instead, it is the"
"formed during the past half billion years when the Earth's crust underlying the Northern Appalachians was the site of two major geological episodes, each of which has left its imprint on the area's bedrock. Between about 450 million years ago and about 250 million years ago, the Northern Appalachian region was affected by a continental collision, in which the ancient African continent collided with the ancient North American continent to form the supercontinent Pangaea. Beginning about 200 million years ago, the present-day Atlantic Ocean began to form as plate tectonic forces began to rift apart the continent of Pangaea. The"
"today."" Early humans may have comprised a large, interbreeding population dispersed across Africa whose spread was facilitated by a wetter climate that created a ""green Sahara"", around 330,000 to 300,000 years ago. The rise of modern humans may thus have taken place on a continental scale rather than being confined to a particular corner of Africa. Hublin and his team also attempted to obtain a DNA sample from these fossils, but these attempts were unsuccessful. Genomic analysis would have provided necessary evidence supporting the conclusion that these fossils are representative of the main lineage leading up to modern humanity, and"
"Atlantica Atlantica (; ""Atlantika"") is an ancient continent that formed during the Proterozoic about (two billion years ago, Ga) from various 2 Ga cratons located in what is now West Africa and eastern South America. The name, introduced by , was chosen because the continent opened up to form the South Atlantic Ocean. Atlantica formed simultaneously with Nena at about 1.9 Ga from Archaean cratons, including Amazonia in present-day South America, and the Congo, West Africa and North Africa Cratons in Africa. Atlantica separated from Nena between 1.6–1.4 Ga when Columbia — a supercontinent composed of Ur, Nena, and Atlantica"
"Euramerica Euramerica (also known as Laurussia – not to be confused with Laurasia, – the Old Red Continent or the Old Red Sandstone Continent) was a minor supercontinent created in the Devonian as the result of a collision between the Laurentian, Baltica, and Avalonia cratons during the Caledonian orogeny, about 410 million years ago. In the Late Carboniferous, tropical rainforests lay over the equator of Euramerica. A major, abrupt change in vegetation occurred when the climate aridified. The forest fragmented and the lycopsids which dominated these wetlands thinned out, being replaced by opportunistic ferns. There was also a great loss"
"continents have been accurately determined back to the early Jurassic, shortly before the breakup of Pangaea (see animated image). The earlier continent Gondwana is not considered a supercontinent under the first definition, since the landmasses of Baltica, Laurentia and Siberia were separate at the time. The following table displays historical supercontinents, using a general definition. There are two contrasting models for supercontinent evolution through geological time. The first model theorizes that at least two separate supercontinents existed comprising Vaalbara (from ~3636 to ) and Kenorland (from ~2720 to ). The Neoarchean supercontinent consisted of Superia and Sclavia. These parts of"
"voyage that year along the Atlantic coast of North America, land that is now part of the United States and Canada. New World The New World is one of the names used for the majority of Earth's Western Hemisphere, specifically the Americas (including nearby islands such as those of the Caribbean and Bermuda). The term originated in the early 16th century after Europeans made landfall in what would later be called the Americas in the age of discovery, expanding the geographical horizon of classical geographers, who had thought of the world as consisting of Africa, Europe, and Asia, collectively now"
"Europe and Asia together as a single continent, dubbed ""Eurasia"". In this model, the world is divided into six continents, with North America and South America considered separate continents. Geologists use the term ""continent"" in a different manner from geographers. In geology a continent is defined by continental crust: a platform of metamorphic and igneous rock, largely of granitic composition. Some geologists restrict the term 'continent' to portions of the crust built around stable Precambrian ""shield"", typically 1.5 to 3.8 billion years old, called a craton. The craton itself is an accretionary complex of ancient mobile belts (mountain belts) from"
"a great quantity of Land, not separated by any Sea from the rest of the World, as the whole Continent of Europe, Asia, Africa."" In 1727, Ephraim Chambers wrote in his ""Cyclopædia,"" ""The world is ordinarily divided into two grand continents: the old and the new."" And in his 1752 atlas, Emanuel Bowen defined a continent as ""a large space of dry land comprehending many countries all joined together, without any separation by water. Thus Europe, Asia, and Africa is one great continent, as America is another."" However, the old idea of Europe, Asia and Africa as ""parts"" of the"
"Mediterranean from the temperate climate regions of Western and Central Europe. The Mediterranean Basin was shaped by the ancient collision of the northward-moving African-Arabian continent with the stable Eurasian continent. As Africa-Arabia moved north, it closed the former Tethys Sea, which formerly separated Eurasia from the ancient super continent of Gondwana, of which Africa was part. At about the same time, 170 mya in the Jurassic period, a small Neotethys ocean basin formed shortly before the Tethys Sea was closed at the eastern end. The collision pushed up a vast system of mountains, extending from the Pyrenees in Spain to"
"Paleozoic the majority of all continental landmasses were united in the paleocontinent of Gondwana, containing the crust of future Africa, South America, southern Eurasia, Australia and Antarctica, which lay centered on the South Pole. Between 650 and 550 million years ago (in the Ediacaran period) the smaller continents of Laurentia (containing the future northeast section of North America), Baltica and Siberia had separated from Gondwana to move northward towards the equator. In the process, the Iapetus Ocean between Gondwana, Baltica and Laurentia closed. In the Early Ordovician period (about 480 million years ago) the microcontinent (a small fragment of continental"
"the southern portion of Laurasia. Paleocontinent A paleocontinent or palaeocontinent is a distinct area of continental crust that existed as a major landmass in the geological past. There have been many different landmasses throughout Earth’s time. They range in sizes, some are just a collection of small microcontinents while others are large conglomerates of crust. As time progresses and sea levels rise and fall more crust can be exposed making way for larger landmasses. The continents of the past shaped the evolution of organisms on Earth and contributed to the climate of the globe as well. As land masses break"
"are Zealandia, emerging from the sea primarily in New Zealand and New Caledonia, and the almost completely submerged Kerguelen Plateau in the southern Indian Ocean. Some islands lie on sections of continental crust that have rifted and drifted apart from a main continental landmass. While not considered continents because of their relatively small size, they may be considered microcontinents. Madagascar, the largest example, is usually considered an island of Africa but has been referred to as ""the eighth continent"" from a . ""Continents"" may be defined differently for specific purposes. The Biodiversity Information Standards organization has developed the World Geographical"