Ancient Wildfires in India’s Godavari Basin Unlock Secrets of Earth’s Fiery Past

In the heart of peninsular India, nestled deep beneath the sedimentary layers of the Godavari Basin, lies a geological archive teeming with the soot-stained remnants of Earth’s distant past. This ancient record—blackened by wildfires that raged hundreds of millions of years ago—has now been decoded by a team of Indian scientists who have employed cutting-edge techniques to reveal the role of palaeofires in shaping Earth's early landscapes, climate, and even the origin of coal.

This pioneering study, conducted by scientists from the Birbal Sahni Institute of Palaeosciences (BSIP) in Lucknow under the Department of Science and Technology (DST), has brought to light an era marked by intense wildfires during the Permian period, approximately 250 million years ago. By applying a multi-disciplinary analytical approach to Permian-age shale samples from the Godavari Basin, the team has added a vital chapter to Earth’s palaeoclimate narrative.

Unraveling the Charred Past

The project began with the collection of fine-grained shale—a sedimentary rock type rich in organic matter—from deep within the basin. These rock samples, preserved through deep geological time, offered a microscopic window into the organic debris left behind by ancient fire events.

Using palynofacies analysis, a method that categorizes organic components in sedimentary rocks, researchers were able to differentiate between various microscopic forms of preserved matter. The analysis identified:

• Translucent Organic Matter (TrOM): Including fragments of pollen, spores, and other plant debris.

• Palaeofire-Induced Charcoal (PAL-CH): Clear microscopic evidence of past vegetation fires.

• Oxidized Charcoal (OX-CH): Indicative of charcoal that had undergone post-burning transportation or weathering.

This analysis offered a unique stratified perspective of prehistoric wildfires, enabling the scientists to determine not just the presence of fire, but where and how it burned.

The Science Behind the Findings

To build on the palynological data, the research team, led by Dr. Neha Aggarwal, employed a suite of sophisticated geochemical and spectroscopic tools:

• Raman Spectroscopy was used to characterize the molecular structure of carbonized particles.

• Rock-Eval Pyrolysis analyzed the thermal breakdown of organic matter, crucial for understanding hydrocarbon potential and combustion history.

• Fourier Transform Infrared (FTIR) Spectroscopy provided insights into the chemical bonds within the charcoal, distinguishing between in situ and ex situ fire deposits.

Together, these techniques allowed for a clear distinction between charcoal that originated from fires at the site (in situ) and material that had been carried in from elsewhere (ex situ). This level of resolution marks a significant advancement in palaeofire research, which had previously been hindered by the inability to differentiate between transported and local fire residues.

Permian Fires and Planetary Oxygen

The presence of widespread macroscopic charcoal in the Permian coal seams of Gondwana, of which India was a part, had long suggested fire activity. However, until now, the origin, nature, and environmental context of these fires remained poorly understood.

One pivotal factor that may have fueled these extensive wildfires was the high concentration of atmospheric oxygen during the Permian—estimated to be significantly higher than today's levels. Elevated oxygen would have increased fire frequency and intensity, especially in the palaeomire ecosystems—ancient peat-forming wetlands—which were vulnerable to seasonal droughts.

Stratigraphy: The Fire Archive's Hidden Key

The study also revealed that stratigraphy—the layering of sedimentary rock—played a crucial role in how charcoal was preserved. During regressive phases (when sea levels fell), organic matter including charcoal was better preserved, creating distinct fire layers. In contrast, during transgressive phases (when sea levels rose), the sediment was more disturbed and oxidized, leading to mixed and degraded fire records.

This pattern offers a geological lens to decode palaeoenvironmental changes, showing how fluctuations in sea levels could influence not only sediment deposition but also wildfire frequency and preservation.

Implications for Climate and Carbon Research

Understanding the transformation of organic matter during palaeofires is not just an academic exercise—it has significant implications for modern climate science. These ancient fires played a key role in carbon sequestration, locking large amounts of carbon into Earth’s crust in the form of coal and kerogen.

By refining our understanding of how carbon was historically cycled and stored, such studies can inform modern strategies to mitigate climate change. The Godavari Basin research also enhances our ability to reconstruct ancient ecosystems, refine geological dating methods, and forecast long-term environmental changes.

A New Flame in Palaeoscience

Published in the prestigious journal ACS Omega, this study is more than a scientific milestone—it represents a new paradigm in reconstructing Earth’s fiery past. By integrating palynology with high-resolution chemical analysis, Indian researchers have illuminated the smoky pages of a story written in ash and stone.

The Godavari Basin, once a cradle of fire, now serves as a beacon for understanding how ancient climates shaped the world we live in today. And as the Earth warms and wildfires once again dominate global headlines, the echoes from the Permian period may offer both cautionary tales and pathways to resilience.