News: According to a recent study based on fossil leaves, Indian monsoon 25 million years ago resembled present-day Australia’s. Understanding the past dynamics of Indian monsoon will help in climate modelling for future monsoon prediction.
- The morphological characters of fossil leaves from different geological ages collected from Deccan Volcanic Province, East Garo Hills of Meghalaya, Gurha mine in Rajasthan and Makum Coalfield in Assam were analysed.
- Plant leaf morphological characters such as apex, base and shape are ecologically tuned with the prevailing climatic conditions to adapt for all the seasons throughout the year.
- The results indicated that the fossil leaves from India were adapted to an Australian type of monsoon and not the current Indian monsoon system during its voyage.
- After India separated from Gondwana, its 9000 km northward voyage from the Southern Hemisphere to its modern position joined with Eurasia took 160 million years.
- The reconstructed temperature data show that the climate was warm (tropical to subtropical) at all the studied fossil sites with temperatures varying from 16.3–21.3 degrees C.
- All the fossil sites experienced high rainfall, which varied from 191.6 cm to 232 cm.
How did Indian separate from Gondwana?
- More than 140 million years ago, India was a part of the supercontinent called Gondwana.
- The Gondwana was composed of modern South America, Africa, Antarctica, and Australia.
- Tethys Ocean – an immense body of water separated Gondwana from Eurasia. When this supercontinent split up, a tectonic plate composed of India and modern Madagascar started to drift away.
- Then, India split from Madagascar and drifted north-eastward with a velocity of about 20 cm/year.
- The continent collided with Eurasia about 50 million years ago, giving rise to the Himalayas.
- Nowadays, India is still moving in the same direction but with a lower velocity of about 4 cm/year, due to the resistance of the Eurasian plate.