HYDERABAD: In what could be a major geological discovery in the State, ash from Toba volcano in Indonesia which had erupted some 75,000 years ago, was found spread across half-a-kilometer area in Hastalpur village of Narsapur mandal in Medak district.
BV Bhadra Girish, a researcher of Kotha Telangana Charithra Brundam (KTCB), who was recently on an exploration of the prehistoric rock art site at Pandavulagutta in the village, was informed by the villagers that there were mounds of ash in the village, and that they have been using the chunks of it as chalk and for other household purposes.
It was earlier believed that the presence of a prehistoric site and microliths found in that area could have meant that there was an iron smelting unit there in those times, and that the ash could have formed as a result of the smelting process from the furnaces.
However, the ash mounds were as deep as two feet, and Girish took the samples for analysis. Upon examining the particles under the microscope and testing them in the laboratory, he found that there was almost no carbon in them, and that there was 5 mg content of sulphur in them. He also found that the particles had sharp edges as found in the ash of volcanic lava.
Chakilam Venugopal, former deputy director of Geological Survey of India, upon re-examining the details, has confirmed that the ash was indeed the volcanic ash of the Toba volcano which had erupted in Indonesia 75,000 years ago. Toba is one of the volcanic mountains in Sumatra islands.
It is noteworthy that Hastalpur is located on the banks of the Haridra, a tributary of Manjira River.
Venugopal informed TNIE that geologists already identified such ash piles at Murreru near Kothagudem and also in some parts of the Manjira valley in the past.
It is said that the piles of ash called ‘merugu sudda’ in Jwalapuram village near Banaganipalli village in Andhra Pradesh was also part of these. He said that the Toba volcano had erupted so violently, that its lava ash was found in the Bay of Bengal and other river valleys of the Deccan plateau in India.
He also opined that the ash mounds in other parts of Telangana may not have been those formed by burning cattle dung in the prehistoric era as it was believed earlier, and felt that such previous observations needed to be revisited.