Meghalayan Age | UPSC CSE

Why in News: When we think of Meghalaya, misty hills, caves, and cascading waterfalls come to mind — but this northeastern state has also earned a rare distinction: it lends its name to the youngest age in Earth’s geological history, the Meghalayan Age.

Officially recognised in 2018 by the International Union of Geological Sciences (IUGS), the Meghalayan Age represents the most recent chapter of the Holocene Epoch — a reminder that India now features in the Earth’s official geological calendar.

What is the Meghalayan Age?

• Time Period: The Meghalayan Age began 4,200 years ago (around 2200 BCE) and continues to the present.
• It marks the latest subdivision of the Holocene Epoch, which started about 11,700 years ago, following the end of the last Ice Age.
• The Meghalayan period was defined by a catastrophic, century-long global drought, which led to the collapse of several ancient civilisations.

How It Was Discovered: The Mawmluh Cave Connection

• The Mawmluh Cave near Cherrapunji (Sohra), Meghalaya, became the Global Boundary Stratotype Section and Point (GSSP) — the official reference point for the start of the Meghalayan Age.
• Inside this cave, scientists studying stalagmites (mineral formations growing upward from the cave floor) found a distinct oxygen isotope signature, indicating a sharp drop in monsoon rainfall.
• This evidence matched data from other parts of the world, confirming a global climatic event — a prolonged drought around 2200 BCE.

Global Impact: A Drought that Changed History

The 4.2-kiloyear event (the Meghalayan drought) triggered widespread climatic upheaval:

• Collapse of ancient civilisations, including:
  • The Akkadian Empire in Mesopotamia,
  • The Old Kingdom of Egypt, and
  • The Indus Valley Civilisation in South Asia.
• Massive changes in monsoon patterns and global agriculture.
• Migration of populations and shifts in cultural centres.

Scientific Classification

• Eon: Phanerozoic
• Era: Cenozoic
• Period: Quaternary
• Epoch: Holocene
• Age: Meghalayan (the youngest of three Holocene ages)

Holocene Subdivision	Time Before Present (Years)	Key Event
Greenlandian	11,700 – 8,200	End of last Ice Age
Northgrippian	8,200 – 4,200	Cooling event
Meghalayan	4,200 – Present	Global drought and collapse of civilisations

Why It Matters

• The Meghalayan Age is the first geological age named after an Indian location.
• It underscores the importance of India’s geological heritage and the global significance of the Indian monsoon system.
• It also highlights how climate change has shaped human civilisation since ancient times — offering lessons for our modern world facing similar challenges.

Source: Indian Express

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