'Fresh findings on Iron should be viewed from the prism of South India'

Recent archaeological findings based on excavations in parts of Tamil Nadu have shown that usage of iron in the state dates back over 5,300 years (3345 BCE). This fascinating piece of information was revealed in the report ‘Antiquity of Iron’ by the Tamil Nadu State Department of Archaeology (TNSDA). 

In an interview with DH’s E.T.B. Sivapriyan, Prof K Rajan, a renowned academic and co-author of the report, dwells on how they arrived at the findings, the way samples were collected, and the way forward. 

Rajan also said excavation of more sites across South India could throw new dates which could help understand the context of iron in India while maintaining that the new findings and morphological study of IVC signs and graffiti marks could lead to a relook and reassessment of several hypotheses vis-à-vis Indus Valley Civilization and settlements in Southern India. 

Edited excerpts:

The report pushes the introduction of Iron in TN by 1,000 years than it was previously thought, making it the oldest date for the Iron Age in India. How did you arrive at this conclusion?

We never expected to get such an early date (3345 BCE through AMS dating of artefacts unearthed from Sivagalai). Our journey tracing the Iron Age in Tamil Nadu began with Mangadu and Thelunganur sites. The mean value date of 1300 BCE for steel unearthed in Thelunganur instilled the belief in us that iron production could go further back. In Mangadu, iron implements yielded a date of 1416 BCE. 

These two dates gave us the confidence that carbon dating of artefacts from various sites in TN would throw more clarity on the introduction of Iron. By then, Gachibowli (Telangana) was dated to 2200 BCE through optically stimulated luminescence (OSL) and Brahmagiri in Karnataka (2140 BCE). 

The dates from the neighbouring states indirectly indicated that the use of Iron in this region (South India) could go before 2000 BCE. The Accelerator Mass Spectrometry (AMS) date of 2172 BCE in Mayiladumparai also fell in the range of Gachibowli and Brahmagiri. 

More clues came from Sivagalai with paddy husks found in a burial urn dating back to 1155 BCE and high tin bronze to 1400 BCE. Our luck was that we could find an identical location to Adichanallur, a protected site, in Sivagalai on the left bank of river Thamirabarani. 

The results of the AMS dating (3345 BCE) came in 2021, but since the date jumped by over a millennium from the previously known period, we began sending multiple samples for AMS and OSL dating to consolidate our findings. 

As a result, we got a series of dates starting from 2400 BCE to 3345 BCE. Thus, we concluded that the entire South Indian region must have experienced the Iron Age around 2500-3000 BCE (the mean value).  

The report says iron implements were found within and outside an urn. How were the carbon samples collected for AMS and OSL dating? 

Instead of relying solely on charcoal, we sent a piece of the urn (ceramic) to Birbal Sahni Institute of Palaeosciences (BSIP), Lucknow. The OSL date we got from BSIP and the AMS date from Beta Analytical Laboratory, Florida, US went hand-in-hand. To be extremely cautious as any professional agency should be, we sent the same sample to the Physical Research Laboratory, Ahmedabad for further analysis. 

Dates from three laboratories deploying two techniques matched with each other and they fell in the same period. Charcoal and carbon samples also synchronised with each other. That’s why we say it is ideal to conclude that Iron was introduced in the middle of the 3rd millennium (2500 BCE-3000 BCE) in South India. 

Though we have two dates in the 4th millennium, I prefer to be cautious as an academician. Hence, we took the lower-end date, middle of the 3rd millennium. 

What is the real significance of the finding in the Indian context? 

The biggest issue in South India is that we don’t have Copper ore and the stratigraphical position in southern Tamil Nadu is that immediately after the Microlithic Age, we get the Iron Age. The vertical sequence in India is the Microlithic Age, Neolithic Age, Copper Age, and Iron Age. 

In Karnataka and AP, the sequence is Microlithic Age, Neolithic Age, and Iron Age, which is also reflected in northern Tamil Nadu, where findings from different excavation sites are uniform. But in Southern TN, we get the Iron Age immediately after the Microlithic Age. 

Since the date for the introduction of the Iron Age wasn’t fixed, we thought people continued with Microlithic and they entered into the Iron Age around the first millennium BCE. 

Luckily, TNSDA and ASI located a habitation mound in Adichanallur, which eluded archaeologists for decades. Till then, only burial sites were found since excavations began there in British India. In the habitation mound, it was found that the stratigraphical position of black-and-red ware was identical to what we got in burial sites. The samples from the habitation site are contemporary to the samples in burial sites and date back to 2522 BCE.  

But with the fresh introduction of Iron available to us, we can say that South India experienced the Iron Age when North India was enjoying the Copper Age with the reason being the availability of commercially exploitable iron ore in South India. 

Dates from Brahmagiri, Gachibowli, Mayiladumparai, Kilnamandi, Adichanallur, and Sivagalai give a broad picture of the introduction of iron in the region. If we dig more, we may get more dates. 

Any future research being planned on whether Iron technology went from here? 

With a series of new dates, the biggest question before archaeologists is about the technology used to make Iron objects. We have to go for a metallurgy analysis, which won’t change the date, but will shed much-needed light on the technological aspect of Iron objects. We may get some more dates as excavations are currently on in many locations in Tamil Nadu. 

The metallurgical analysis will dwell into the technological advancements of the Iron Age of the early and later iron pieces. It will also look into whether there was any change in the technology over the years and which of the two iron ores -- magnetite and laterite – available in South India were used.  

For instance, the furnace found in the Mettur region is different from the one found in Pudukkottai (lateritic zones). 

Since the earlier date for the Iron Age was 1000 BCE, we didn’t focus on this aspect, but now that we have a much earlier date, the technological aspects have to be extensively addressed and studied. 

We have to identify the furnace, collect samples, and send them for a metallurgy analysis since all compositions need to be known to find out the technological aspect of early iron tools. In the past, we extracted carbon from a piece of steel in Thelunganur and dated it. 

If we get any pure, non-rusticated core from iron tools from our sites, we may attempt to extract carbon from it and directly date the iron tool. That will consolidate or support our findings.

Is it right to say that Iron was first introduced in Tamil land? Do we have enough evidence to say this conclusively? 

No technology can be specific to one zone. We can safely say Southern India because the entire zone is iron-rich and technology might have travelled quickly within the region. Since the TNSDA has been provided substantial financial support by the government to undertake programs, we have been able to date several samples and arrive at various dates. 

Gachibowli and Brahmagiri are also closer to us and we might get more dates if states conduct more excavations, date the samples, and analyse them scientifically. Even if we get any new sites, we have to place the entire South as one geographical zone, the iron ore bearing zone. 

While agreeing with the hypothesis arrived at in the report, experts like Ravi Korisettar pitched the need for further substantiation as “one or two sites will not answer the question.“ Do you agree?

Yes, archaeologists will demand further evidence, and rightly so. That’s the reason we tested several samples to substantiate the 3345 BCE period we got from AMS dating. The comments given by experts are uniform and they have taken the mean value. Normally, I take the lower-end date. Whatever may be the date, everything goes earlier than what we had already established. The academic community will ask for more dates for substantiation, and we will continue to take efforts to send more samples for dating to substantiate our findings. 

Do you think the findings will lead to the digging of more Iron Age sites across South India? 

The academic community has understood the implications of the new date which demonstrates the fact that there was an advanced technology (of iron) involved in making agricultural implements. The presence of paddy shows that agricultural production was in full swing, which means that the habitants were economically prosperous. 

Tools like iron, high tin bronze, and gold, artefacts like carnelian beads, and agate beads not just indicate the economic prosperity but also the buying capacity of the society. It is a chain of reaction like we believe people began to communicate through signs and later through a script. In Thulukarpatti alone, we excavated 5,000 graffiti marks, which is a clear indicator that people were literate. 

With the fresh dates, people from neighbouring states will get enough confidence to dig more and date the sites. If we work together, we will get a complete picture in about 10 years as the findings will be beneficial to the whole of India, not just Southern India. Tamil Nadu has proven the dates scientifically, and other states will prove them in the future. 

TNSDA’s morphological study found 60% of the signs on seals and 90% of the graffiti marks found on ceramics have parallels with those found in the IVC (Indus Valley Civilisation). What is the significance of the findings?

The findings (the morphological study and recent AMS and OSL dates) make it clear that the South Indian Iron Age is contemporary to the Copper Age of North India, which includes the Indus Valley Civilisation and the Central Indian Chalcolithic Age. Even inhabitants of IVC were aware of Iron technology but archaeologists have so far emphasised the usage of Copper, but in the future, they may reassess. 

In South India, we have found Carnelian and agate beads of Gujarat and Maharashtra which means that the two regions had links/contacts between them. Black-and-redware and graffiti marks are found in South India and IVC as well. Some people believe gold went to IVC from Karnataka. 

Before these findings, no contemporary culture of IVC was found in South India, and hence questions were raised on how we can compare. The hypothesis that people from IVC might have moved here after the downfall of the civilization there might have to be relooked. I am very clear that not only IVC but the entire Indian sub-continent was culturally integrated by around 2500 BCE. 

What was the goal behind the study? 

We have published IVC signs and will soon publish Tamil Brahmi scripts and graffiti along with concordance. For anyone willing to work on IVC signs, our project will be the basic data along with drawings, and photographs. They can search for symbols digitally. I may succeed or may not succeed in deciphering the IVC signs, but someone might succeed and get the USD 1 million prize (announced by the TN government).

Our goal is to share every information that we get in the public domain since our research is funded by public money. People will take forward the research, like how there has been a debate on the Indus script for the past 100 years. We are merely helping researchers with data.