SSC Selection Post 2025 PYQ — Question 9

Correct Answer

Indian & Eurasian

Explanation

The primary geological event that led to the formation of the majestic Himalayan mountain range is the convergent collision between the Indian Plate and the Eurasian Plate. This slow-motion continental collision began approximately 40 to 50 million years ago during the Eocene epoch and continues to drive the upward growth of the mountains to this day.

The overarching goal of studying this boundary is to understand how massive fold mountain systems are built through plate tectonics. Before the collision, a vast ancient ocean known as the Tethys Sea existed between the two landmasses. As the northward-moving Indian Plate pushed relentlessly into the southern edge of the stable Eurasian Plate, the intervening oceanic crust was entirely subducted, and the thick sedimentary layers deposited on the seafloor of the Tethys Sea were intensely crumpled, folded, and uplifted, creating the highest mountain peaks on Earth.

Key Points

Because both colliding segments consist of buoyant continental crust, neither plate could be easily subducted deep into the mantle. Instead, the crust buckled and buckled upward, doubling the thickness of the Earth's crust in the region and forming the vast Tibetan Plateau alongside the Himalayas. This tectonic boundary is classified as a continent-continent convergent boundary. The ongoing northward movement of the Indian Plate at a rate of about 4 to 5 centimeters per year means that the Himalayas remain geologically active, causing the mountain range to rise by a few millimeters annually and making the entire region highly susceptible to frequent, powerful earthquakes.

Important Questions and Answers

Question: What was the name of the ancient sea that vanished due to the collision of the Indian and Eurasian plates?

Answer: The Tethys Sea.

Question: What structural type of mountains are the Himalayas classified as, based on their formation process?

Answer: Fold Mountains.