This animation illustrates the formation of Pangea during the late Paleozoic. Geographic area of interest: North America, South America, Europe, Africa, Rheic Ocean. Geological time interval: 420 Ma (late Silurian) - 300 Ma (Permo-Carboniferous).
keywords: Pangea, plate tectonics, continental collision, Rheic Ocean, Laurentia, Baltica, Gondwana, Caledonide mountains, Appalachian mountains, Allegheny orogent, Varsican mountains, Mauretanide mountains, eustasy, Scotese, animation
Please cite as:
Scotese, C.R., & van der Pluijm, B., 2020. Deconstructing Tectonics: Ten Animated Explorations, "Formation of Pangea: the Wegener Cycle", Earth and Space Science,
7, e2019EA000989. doi. org/10.1029/2019EA000989
More Information:
The closure of the Rheic Ocean led to the formation of a large continental landmass, or supercontinent, called Pangea (meaning “all-land”; Wegener, 1929). At various times in the geologic past, plate movements and continental collisions produced similar supercontinents that lasted for several tens of millions of years before they broke apart.
The supercontinent Pangaea was formed in the late Paleozoic (280 Ma) and rifted apart during the early Mesozoic (180 Ma). An older supercontinent Rodinia was formed at the end of the Mesoproterozoic (~1.1 Ga) and dispersed by ~750 Ma (Hoffman, 1991). There is also evidence that supercontinents formed even earlier in Earth history, such as the supercontinent Nuna that formed at the end of the Paleoproterozoic (~1.8Ga), indicating that supercontinents repeatedly formed and subsequently broke up. This mega-tectonic process is called the Supercontinent Cycle or the “Wegener Cycle” after the German scientist who championed the idea that the landmasses were once joined together in a large continent that he called “Pangea”.
The supercontinent cycle may be related to long-term (more than 100 million years) convection patterns in the deeper mantle. The relative motion of a continent is controlled by plate forces, particularly the downward pull from negative buoyancy of cold and dense plate material (Forsyth and Uyeda, 1975), but over longer periods of time the continental components accumulate over a mantle downwelling to form a supercontinent. Once formed, the thermal structure of the mantle beneath it changes, because the supercontinent acts as a giant insulator that blocks escaping heat from the mantle. In response, the mantle below the supercontinent heats up, and is no longer a region of downwelling. Instead, hot mantle begins to upwell beneath the supercontinent, causing it to heat up and weaken the overlying plate (Anderson, 1982). Eventually, a rift system forms that evolves into a new ocean basin, dispersing the supercontinent.
With the last supercontinent ~250 my old, we are still in the dispersal stage of the supercontinent cycle, but in the next 200 million years or so, the continents may once again coalesce to form a new supercontinent that we call “Pangea Proxima” (see Vignette 10, "Future Earth").
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