Resetting the Archaeological Clock in India….
The Toba volcano is located in Sumatra, in one of the most seismically active regions in the world. Its caldera (Lake Toba) is the largest Quaternary caldera on earth, spanning 100 x 30 kilometers (60×20 miles), and it is close to the junction of the Sumatra Fault Zone and the Investigator Fracture Zone.
It has erupted four times in the last million years or so: the present shape of the caldera is from the latest eruption 74,000 years ago.
That one was a super-eruption, the largest volcanic event which has occurred on our planet in the past two million years.
The Toba super-eruption involved a minimum of 2,800 cubic kilometers (670 cubic miles) of magma, and at least 800 km3 (200 mi3) of volcanic gases and ash were directly injected into earth’s atmosphere.
Northern Sumatra was covered in a thick deposit over an area of 30,000 km2 (11,500 square miles).
The enormously thick atmospheric ash plumes blanketed an area of land between the South China Sea to the Arabian Sea, probably within a period of days or weeks.
The Toba eruption has been interpreted as a significant driver of severe climatic deterioration, and one of the most significant events associated with human evolution. At a minimum, the ashfall would have polluted the lower atmosphere and water sources for many years.
Dips in average temperature associated with Toba have been seen in Greenland ice cores. The eruption and the subsequent cooling of the earth in Marine Isotope Stage 4 (MIS4) have been cited as responsible for the disappearance of our species from Eurasia.
Early modern humans arrived in Eurasia approximately 100,000 years ago and are in evidence from what is today the Czech Republic and Israel. But there is a large gap between those first sites and the flourishing of humans in Europe and Asia, about 45,000 years ago that has been tentatively attributed to the effects of the Toba eruption.
Recent analysis, however, suggests that the Toba did not exude as much sulfur as previously estimated, and the climatic upheaval was not as drastic.
Evidence of the impact on the human populations in India is variously interpreted. The earliest possible evidence for hominids in the Indian subcontinent is between 108,00 and 128,000 years ago: Middle Paleolithic technology is in evidence from 77,000 through 38,000 years ago.
Jwalapuram (“City of fire” in Sanskrit) is an archaeological site in the Kurnool district of Andhra Pradesh, South India, which shows hominid habitation before and after the Toba event. Proving that migration did not occur here as was originally surmised.
Primary ashfall tephra is also clearly associated with Middle Paleolithic occupations in the Jurreru Valley of southern India, and the Middle Son Valley in Madhya Pradesh of northern India. But here there is apparently no Middle Paleolithic occupation before the ash fall, and after the ash fall the Middle Son remained empty for some 50,000 years.
Archaeological and geological studies have been conducted in Madhya Pradesh since the 1980s, and in Andrah Pradesh at the Jwalapuram sites in the Kurnool district since 2003.
Author: Paxo Jones
Source: Quaternary International