Tamil Nadu Natural Resources Minister T K Prabhu informed the Assembly on Tuesday that indiscriminate mining and illegal quarrying for m-sand and other construction aggregates have flattened around 10 hills and hillocks across the state. He said most of these are nearly 320 crore years old, ancient geological formations that existed before humans emerged.

The minister made the remarks during the discussion on the demands for grants for his department. He said three of the vanished hills are in Perambalur district, two each in Madurai and Coimbatore districts, and one each in Tirupattur and Ranipet districts. The total number and district-wise break-up indicate widespread quarrying activity.

"We have all searched for missing persons at some point in our lives," Prabhu said. "We may have to search for the hills that have disappeared from our state."

The statement highlights the environmental impact of the growing dependence on manufactured sand (m-sand) and the loss of ancient geological features in Tamil Nadu.