Have you ever wondered how India came into existence? We all know that millions of years ago, the land wasn’t divided into continents like it is now but was combined into a singular land mass known as Pangaea. The Pangaea then divided into two supercontinents- Laurasia and Gondwana, due to continental drift. It happened during the late Neoproterozoic and early Paleozoic. Laurasia was further divided into subcontinents Asia and Europe while Gondwana was divided into Africa, Antarctica, and India. But how did India which was a part of Gondwana drifted away to join Asia (continent born from supercontinent Laurasia)?
“The Indian subcontinent, or simply the subcontinent, is a physiographical region in Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian Ocean from the Himalayas.”
The Pangea theory and Continental drift
Continental drift describes one of the earliest ways geologists thought continents moved over time. It formed two supercontinents Laurasia and Gondwana divided by the Tethys Ocean, which eventually moved to form the continents we know today. Fossils of similar organisms across widely disparate continents encouraged the revolutionary theory of continental drift. And this continental drift gave birth to Alfred Wegener’s Pangaea Theory. In the early 20th century Wegener published a theory that suggests that around 240 million years ago, the earth’s land mass wasn’t divided into different continents but was one large, singular chunk of land mass. His theory explained how the continental landmasses were “drifting” across the Earth. He studied geology, botany, and fossil remains of these continents and discovered that fossils found in India have similar characteristics to those found in Africa. However, today between India and Africa lay an enormous ocean and no animal or a plant could have possibly swum across it.
For example, fossils of the ancient reptile Mesosaurus are only found in Africa and South America. Mesosaurus, a freshwater reptile only one meter long, could not have swum the massive Atlantic Ocean located between these two continents. So how did the same fossil remain was discovered on two entirely different continents? The presence of such fossil remains suggests that they have shared a rich legacy of single habitat and that once Africa and South America were not divided by the Atlantic Ocean. Though initially, Wegener’s Pangaea theory did not receive a thumbs up from the geologists, later studies concluded that the theory is indeed relevant.
To understand this concept visually, try looking at the world map, you’ll see that the border of many continents looks like a jigsaw puzzle which if put together would look like a single land mass. One of the biggest questions Wegener faced in publishing his theory was- what was the reason behind continental drift and what mechanism did they follow? Wegener thought that continental drift was caused due to earth’s rotation, but the tectonic activity scientists had otherwise to say. All the land mass, be it continents or countries lies on tectonic plates which are the massive slabs of rock above the earth’s mantle. These plates are always moving and interacting in a process called plate tectonics. This happens due to the internal heat pressure created from the Magna causing the convection cycle and the process thus allows continents to move. Interestingly, continents are still moving today.
One more astonishing theory was that 240 million years ago, when the singular supercontinent Pangea existed was also the dinosaur era and that the whole extinction of dinosaur life wasn’t caused by a simple meteorite attack, in fact, the procedure started thousands of years before it. In the initial years of the Jurassic period, Pangea slowly started tearing apart, and the strong plumes inside the earth surface started creating volcanic hotspots.
But how did India become part of Asia? These plumes were also the reason why India drifted away from Gondwana. India’s inner surface is only 100 kilometers wide while the other continents of Gondwana like America had tectonic plates 180-300 kilometers wide. This is the reason why India is moving towards Asia at the speed of 18-20 cm each year while the other continents are drifting at the speed of 4 cm each year. This makes India’s movement 4 times faster than the rest of the continents.
But this movement wasn’t simple. Because the tectonic activity was wide thus more volcanic hotspots and eruptions started causing a massive threat to the life on earth which was none other than the dinosaurs. These eruptions released poisonous gases into the atmosphere and the high concentration of mercury just added the toll. The mercury was also mixed with the water increasing the sulfur level which acidified the water. This continued for millions of years. Today we know that the Chicxulub asteroid was the reason behind the extinction of dinosaurs which is true enough but incomplete. Yes, the Chicxulub asteroid was responsible for the extinction of dinosaurs, but it wasn’t the only thing that influenced it. Thousands of years before it, continental drift was already causing a great threat to life and the asteroid attack was simply one last blow that caused an end to the Jurassic period. Thus, in simple words, even if the asteroid attack never happens, the extinction of dinosaurs was an inevitable event.
Coming back to the drift of India, the fast-drifting speed caused the collision of India with Asia around 5 crore years ago. The Himalayan range we have today was the by-product of this collision. But the Himalayans weren’t created just after the collision, it took thousands of years to stand this tall. Even today as India is still moving, the Himalayas grow by 1 cm each year. And this movement of the Indian plate is also responsible for the frequent earthquakes occurring in Nepal and Western China.
This is how India became a part of Asia and continues to move towards it. It would probably take another 200 million years but just as the continents were once drifted away from one another would again come together to form a singular landmass. The only question is- how would we prepare ourselves?