Answer:

Introduction

The Earth’s lithosphere, comprising several major tectonic plates (seven to eight), and numerous minor ones, undergoes continuous relative motion, influencing our planet’s geological features and giving rise to phenomena like earthquakes, volcanic eruptions, mountain-building etc. along plate boundaries. Among these geological events, the Indian Subcontinental plate’s collision with the Eurasian plate marked a pivotal moment, beginning the formation of the Himalayan mountain range 50 million years ago.

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Geodynamic Processes Underlying the Collision and Formation of Himalayas:

• Convergence of Tectonic Plates:
  • The primary geodynamic process is the convergence of these two massive tectonic plates.
  • Initially, India began drifting northward towards Asia as the supercontinent Pangea broke apart around 200 million years ago. 
  • By 80 million years ago, India was positioned 6,400 kilometers south of the Asian continent, moving towards it at a rate of 9 to 16 centimeters per year. 
  • Approximately 50 to 40 million years ago, the rate of northward drift of the Indian continental plate slowed to around 4 to 6 centimeters per year. 
  • This deceleration marked the onset of the collision between the Eurasian and Indian continental plates, the closure of the former Tethys Ocean, and the initiation of Himalayan uplift. 
  • This collision resulted from the plate tectonics framework, where plates move due to convective currents in the Earth’s mantle.
  • Subduction and Compression: Since both the Indian and Eurasian plates are continental, neither of them could be subducted due to their buoyancy. Instead, they experienced compression and pushed against each other, with the Indian plate moving northward and upward into the Eurasian plate.
• Crustal Thickening: As the Indian plate pushed into the Eurasian plate, it underwent crumpling and folding due to immense compressive forces. This process, known as crustal thickening, caused the deformation, folding, and uplift of sedimentary layers originally deposited in ancient oceans that once separated these landmasses. This gave rise to the magnificent Himalayan mountain range, extending 2,900 kilometers along the border between India and Tibet.
• Continuous Mountain Building: Over millions of years, the Himalayas have continued to rise as the Indian plate pushes northward into the Eurasian plate, resulting in the formation of some of the world’s highest peaks, including Mount Everest. This mountain-building process is still ongoing at a rate of more than one centimeter per year.
• Erosion Processes: The uplift of the Himalayas is counteracted by erosion processes, primarily influenced by the region’s monsoon climate. This climate continuously erodes the mountains and carries sediments into the neighboring rivers and basins, such as the Ganges, Brahmaputra, and Indus rivers, sculpting the landscape over millennia.

Conclusion

The collision of the Indian Subcontinental plate with the Eurasian plate has resulted in the upliftment of the majestic Himalayas, driven by various geodynamic processes, and it continues today. This ongoing geological phenomenon remains a significant focus of current research and exploration, underscoring the ever-changing nature of our planet’s surface.

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