IIT KGP Researchers say Indus Valley civilization in India is older than thought before

The rise of the post-Neolithic Bronze Age Harappan civilization 5700 – 3300 years before present, spread along the Indus Valley of Pakistan through the plains of NW India, including into the state of Gujarat and up to the Arabian Sea and its subsequent decline has remained an enigma in archaeological investigation. In the Indian subcontinent the major centers of this civilization include Harappa and Mohenjo-Daro in Pakistan and Lothal, Dholavira and Kalibangan in India. In recent years excavation at Rakhigarhi and few other places indicate that the civilization probably was more expansive than thought before. Whatever may be the extent most Harappan settlements grew in the floodplains of river systems including those of the Indus or now defunct Ghaggar-Hakra (mythical river Saraswati?). Many archaeologists believe that weakening of the summer monsoon after ~5000 years and a major drought around 4200 years throughout the Asia probably were the reason behind the Harappan collaps