Sirius Geography

Nikola Kostadinovski & Damian Pang | 18 November 2021

A Radically New Idea

Our planet’s surface shows an extraordinary diversity ranging from icy mountain peaks to rocky shores, and sandy deserts. Land is split up into the several large landmasses that we now consider continents as well as a multitude of islands¹. It is not only the land that is divided, with it we find changes in climate, in biodiversity of both plants and animals, as well as distinct differences in culture, language, art, and politics. These seem old and unchanging divisions. But are they?

At the beginning of the 20^th century, the German geophysicist Alfred Lothar Wegener (1880-1930)² proposed a radical new theory: Continental drift. This new and revolutionary theory suggested that continents have slowly moved relative to each other, and in fact are still moving³! Wegener turned speculation that has been around for centuries into a coherent scientific theory⁴. Although he was mistaken about the underlying mechanics (which was developed by Arthur Holmes soon after⁵, his concept of continents moving apart led him to the conclusion that most of earth’s landmass was once combined a single, unified supercontinent. Wegener called it Pangaea, from the Greek for “all the earth⁶.”

What was Pangaea?

Pangaea (also known as Pangaea) was a enormous continental landmass that comprised all our current continents in an almost completely continuous terrestrial expanse⁷ that existed from ca. 320 to 180 million years ago⁸: It reached its full extent in the early Permian period (299-273 million years ago) and started breaking up around 200 million years ago during the early Jurassic period⁹. This massive C-shaped landmass was encircled by a ginormous ocean called Panthalassa (or Panthalassic Ocean) and surrounded the Tethys Sea in the east¹⁰. Pangaea’s large size meant that its interior was far away from any ocean, which resulted in a dry, desert-like centre with very hot days and super cold nights¹¹. The continent was ravaged by super strong monsoon winds (called the Pangaean megamonsoon) that changed direction throughout the year¹².

Unique Among Supercontinents

Pangaea’s large landmass is what geologists call a supercontinent¹³. More recent research indicates that Pangaea was not the only extensive landmass in earth’s history but that several supercontinents assembled and broke up in a repeating pattern called the supercontinent cycle¹⁴. The term supercontinent is a bit fuzzy but some researchers have defined it as any landmass that includes at least 75% of the continental crust in existence at the time¹⁵. All these criteria are based on Pangaea, the supercontinent we know most about and the first to be classified. It was the discovery of Pangaea that led to the acceptance of the theory of continental drift and Pangaea served as the archetype of what a supercontinent is¹⁶. Pangaea is also unique in other ways: It existed when the oxygen levels in the earth’s atmosphere reached its peak as vegetation flourished¹⁷. Along with the many plant species came a wide variety of animals, including several mass extinctions and subsequent flourishing of different species¹⁸.

Formation

Pangaea formed when the previously formed landmasses Gondwana in the south and Laurasia collided and formed a single, gigantic supercontinent^{19, 20}through the movement of the underlying tectonic plates. The same process also resulted in its eventual breakup and the formation of the numerous, smaller continents we have today.  

Conclusion

Pangaea was an ancient supercontinent that existed from ca. 320 to 180 million years ago. It included all major landmasses on earth today into a single, large terrestrial expanse.

About the Author

Nikola Kostadinovski is a geographer from Macedonia. He studied geography in Skopje at the St. Cyril and Methodius University with the faculty of mathematics and natural sciences. Nikola enjoys researching geography topics to update his knowledge, and also to teach and write on geography-related topics.

¹ Pang, D. (2021). Continents. Sirius Geography. URL: TBA

² Encyclopaedia Britannica (2021). Alfred Wegener. Encyclopedia Britannica. URL: https://www.britannica.com/biography/Alfred-Wegener

³ USGS. (2012). Historical perspective. USGS. URL: https://pubs.usgs.gov/gip/dynamic/historical.html

⁴ Romm, J. (1994). A new forerunner for continental drift. Nature, 367, 407–408. https://doi.org/10.1038/367407a0

⁵ Geological Society of Glasgow. (n.d.). Arthur Holmes. URL: https://geologyglasgow.org.uk/archive/arthur-holmes/

⁶ Harper, D. (n.d.). Etymology of Pangaea. Online Etymology Dictionary. URL: https://www.etymonline.com/word/Pangaea

⁷ Ghose, T. (2018). Facts about Pangaea, ancient supercontinent. LiveScience. URL: https://www.livescience.com/38218-facts-about-pangaea.html

⁸ Mitchell, R. N., et al. (2021). The supercontinent cycle. Nature Reviews Earth & Environment, 2, 358–374. https://doi.org/10.1038/s43017-021-00160-0

⁹ Encyclopaedia Britannica (2021). Pangaea. Encyclopedia Britannica. URL: https://www.britannica.com/place/Pangaea

¹⁰ Encyclopaedia Britannica (2021). Pangaea. Encyclopedia Britannica. URL: https://www.britannica.com/place/Pangaea

¹¹ Parrish, J. T. (1993). Climate of the supercontinent Pangaea. Journal of Geology, 101(2), 215-233. https://doi.org/10.1086/648217

¹² Soreghan, M. J., Soreghan, G. S. L., & Hamilton, M. A. (2002). Paleowinds inferred from detrital-zircon geochronology of upper Paleozoic loessite, western equatorial Pangaea. Geology, 30(8), 695–698. https://doi.org/10.1130/0091-7613(2002)030<0695:PIFDZG>2.0.CO;2

¹³ Mitchell, R. N., et al. (2021). The supercontinent cycle. Nature Reviews Earth & Environment, 2, 358–374. https://doi.org/10.1038/s43017-021-00160-0

¹⁴ Mitchell, R. N., et al. (2021). The supercontinent cycle. Nature Reviews Earth & Environment, 2, 358–374. https://doi.org/10.1038/s43017-021-00160-0

¹⁵ Meert, J. G. (2012). What’s in a name? The Columbia (PaleoPangaea/Nuna) supercontinent. Gondwana Research, 21(4), 987-993. https://doi.org/10.1016/j.gr.2011.12.002  

¹⁶ Meert, J. G. (2012). What’s in a name? The Columbia (PaleoPangaea/Nuna) supercontinent. Gondwana Research, 21(4), 987-993. https://doi.org/10.1016/j.gr.2011.12.002  

¹⁷ Mitchell, R. N., et al. (2021). The supercontinent cycle. Nature Reviews Earth & Environment, 2, 358–374. https://doi.org/10.1038/s43017-021-00160-0

¹⁸ Button, D. J. (2017). Mass extinctions drove increased global faunal cosmopolitanism on the supercontinent Pangaea. Nature Communications,  8, 733. https://doi.org/10.1038/s41467-017-00827-7

¹⁹ Lucas, S. G. (2005). Pangaea. In R. C. Selley et al. (Eds.) Encyclopedia of Geology (pp. 225-228). Cambridge, MA: Academic Press. https://doi.org/10.1016/B0-12-369396-9/00434-2

²⁰ Rogers, J. J. W., & Santosh, M. (2004). Continents and supercontinents. Oxford, UK: Oxford University Press.