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Home › Articles › हिंदी CONTINENTAL DRIFT THEORY: REVISITING ALFRED WEGENER’S REVOLUTIONARY THEORY Related toInternal Security, Science & Tech Published on9 June 2025 Have you ever looked at a world map and noticed how the eastern coastline of South America seems to nestle perfectly into the western coast of Africa, almost like pieces of a giant jigsaw puzzle? This isn’t just a coincidence. It’s a clue to a revolutionary idea that, a century ago, turned the world of geology upside down. This is the story of the Continental Drift Theory, a concept proposed by a German meteorologist named Alfred Wegener. He suggested that our continents are not fixed but are constantly, albeit slowly, wandering across the face of the Earth. While his ideas were initially met with ridicule, they laid the foundation for our modern understanding of the dynamic planet we live on. So, let’s journey back in time and explore this groundbreaking theory. The Grand Idea: A World Once United In the early 1920s, Alfred Wegener put forth a bold hypothesis. He proposed that about 300 million years ago, all of the Earth’s continents were joined together in a single, colossal supercontinent. He named this landmass Pangaea, meaning “all lands” in Greek. This supercontinent was surrounded by a single, vast ocean called Panthalassa, or “all seas”. According to Wegener, Pangaea was not a permanent fixture. He suggested that it was split by a long, shallow sea called the Tethys Sea, which separated it into two smaller supercontinents: Laurasia to the north and Gondwanaland to the south. Then, around 200 million years ago, during the Mesozoic Era, these landmasses began to break apart and drift away from each other, eventually forming the continents as we know them today. The Driving Force: What Powered the Drift? One of the most challenging questions for Wegener was to explain what force could possibly be powerful enough to move entire continents. He proposed two main mechanisms: Pole-fleeing Force: Wegener suggested that the Earth’s rotation creates a centrifugal force, which is strongest at the equator. He believed this force caused the continents to drift away from the poles and towards the equator. Tidal Force: He also theorized that the gravitational pull of the moon and the sun, which causes ocean tides, exerted a westward drag on the continents, causing them to drift. While these ideas were creative, they would later become the theory’s biggest weakness. Modern science has shown that these forces are far too weak to move continents. However, Wegener’s attempt to provide a mechanism, however flawed, was a crucial step in the right direction. The Trail of Clues: Evidence for a Drifting World Wegener was not just a dreamer; he was a meticulous scientist who gathered a wealth of evidence from different fields to support his theory. Let’s look at some of the compelling clues he presented. The Jigsaw Fit: The most apparent evidence was the remarkable fit of the continents. The bulge of Brazil seems to fit perfectly into the Gulf of Guinea in Africa. Similarly, the coastlines of other continents also show a striking correspondence. Geological Match: Wegener pointed out that mountain ranges of the same age and structure appeared on opposite sides of the Atlantic. The Appalachian Mountains in North America, for instance, are geologically similar to the Caledonian Mountains in Scandinavia and Scotland, suggesting they were once part of a single mountain chain. Fossil Evidence: This is where the story gets really interesting. Fossils of the same ancient species were being found in continents that are now thousands of kilometers apart. The fossil remains of Mesosaurus, a small freshwater reptile, have only been found in South Africa and Brazil. It’s highly unlikely that this small creature could have swum across the vast Atlantic Ocean. Fossils of the land reptile Lystrosaurus have been found in India, Antarctica, and Africa, further supporting the idea that these continents were once connected. The fossil fern Glossopteris has been found in rocks of the same age in Australia, Antarctica, India, Africa, and South America. This widespread distribution is best explained if these continents were once part of a single landmass. Ancient Climates and Glacial Scars: Wegener also found evidence of dramatic climate changes in the geological record. Tillite deposits, which are rocks formed by glaciers, have been found in India, Africa, South America, and Australia. These regions are now located in or near the tropics, so the presence of glacial deposits suggests they were once situated in much colder, polar regions. Conversely, coal deposits, which form in warm, swampy conditions, have been found in regions that are now in colder climates. Placer Deposits: A fascinating piece of evidence comes from the distribution of gold deposits. Rich placer deposits of gold are found on the coast of Ghana in West Africa, but the source rocks for this gold are in Brazil. This makes perfect sense if the two continents were once joined together. The Great Debate: Criticisms and Drawbacks Despite the compelling evidence, Wegener’s theory was met with widespread skepticism and criticism from the scientific community of his time. The main objections were: The Inadequate Mechanism: The forces that Wegener proposed—pole-fleeing force and tidal force—were proven to be insufficient to move continents. This was the most significant flaw in his theory. The Nature of the Crust: Wegener envisioned the continents as rafts of solid rock plowing through the softer rock of the ocean floor. Geologists of the time argued, correctly, that this was physically impossible. Selective Evidence: Critics pointed out that Wegener seemed to be picking and choosing evidence that fit his theory while ignoring data that contradicted it. The Timing of the Drift: Wegener could not explain why the drift began only in the Mesozoic Era and not before. For these reasons, the Continental Drift Theory was largely dismissed for several decades. From Ridicule to Revolution: The Modern Perspective So, where does Wegener’s theory stand today? While the mechanism he proposed was incorrect, his fundamental idea of moving continents was spectacularly right. In the
