Summary of Maharashtra’s 3500 Million Years old History

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Maharashtra records the oldest rocks dating right back to 3500 million years to the youngest rocks deposited recently. Biotite Gneiss a metamorphic rock forms the basement of Maharashtra’s extensive area of more than 3.7 Lakh sq Km. Areas like Chandrapur, Gadchiroli, Bhandara and Nagpur districts are covered by intensely deformed and metamorphosed Schists, Gneisses, Quartzites, Marbles, Amphibolites and Hornblende Schists, while the rest is covered completely by Basalts.

It was around 3200 Million years ago, mountain building activities of Sausar and Sakoli lead to folding and faulting in the cratonic landmass (known as the Dharwar craton), which was followed by emplacement of Granites, Pegmatites  and Gneisses evident at places near Nagpur.

This mountain building and emplacement of deep seated rocks on the surface, was soon followed by a long period of quiescence (no activity of sedimentation), also known as Eparchean Unconformity (evident in Tirupati Hills – a National Geo-Heritage Monument). The time gap between the formations is at least 500 Million years! As the boundary is between sedimentary rocks of 1600 million years in age, and granites, gneisses and dolerite dykes that are more than 2100 million years old.

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The then Gondwanaland comprising of Antarctica, India, Australia, South Africa and South America started rifting some 300 million years ago and developed linear troughs around the west coast of India. And as the climate got warmer, melting of ice cover lead to formation of new rivers, depositing glacial sediments in the newly formed sea between India and Africa. Nagpur, Chandrapur and Yavatmal districts of Maharashtra records sediments that were deposited under lacustrine environment developed by melting of glaciers.

Life was at its peak during this phase, enormous species flourished and lived during this period of Earth’s history. It was this phase which made India rich with coal deposits today. (The Coal found in India’s one of the biggest Coal mine,Barkar/Raniganj Coalfields- West Bengal, is the same found in the sandstones and shales of Nagpur,Chandrapur and Yavatmal districts of Maharashtra deposited 300-250 million years ago).

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It was around 65 Million years, India was passing over the Reunion Hotspot which lead to massive outpouring of Lava through fissures along the Maharashtrian thin crust that got stretched when India had separated from Antarctica.

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Only parts of Eastern Maharashtra was saved from the extreme volcanism and outpouring of lava, lasting over million of years and covering entire Maharashtra with flood basalts, known as Deccan Plateau.

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Since then Maharashtra has seen a stable Geological history, having existing landforms weathered and transformed by local weathering agents.

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