Gandhinagar, Oct 27: As global warming intensifies, scientists are exploring ways to reduce carbon dioxide emissions. One emerging approach being explored in environmental research is carbon capture and storage, which involves capturing CO2 and storing it deep underground, away from the atmosphere. In this context, researchers at the Indian Institute of Technology Gandhinagar have investigated ancient volcanic rocks in Maharashtra to assess their suitability for this purpose.
Basalt, the type of volcanic rock investigated in this study, is attracting interest for carbon capture and storage because it contains minerals that can react with CO2 dissolved in water and convert it into stable minerals through a process known as mineralisation. In Maharashtra, these rocks form part of the Deccan Traps, a vast expanse of volcanic rock in west-central India formed by successive lava flows around 65 million years ago. This landscape therefore offers a significant geological setting for investigating the potential of India’s basalt formations for long-term CO2 storage.
By studying Deccan basalt exposed at the surface, researchers can gain insights into similar formations buried underground, a method known as an outcrop-analogue approach. However, these formations are not uniform. Individual lava flows can contain dense rock, fractures, pores and cavities and differ in mineral composition.
“These features influence how fluids move through the rock and interact with it. Understanding variations in internal architecture and the characteristics of individual lava flows is therefore important to identify which formations may be suitable sites for CO2 to be pumped at a commercial scale,” said corresponding author Prof Pankaj Khanna, Associate Professor at IITGN’s Department of Earth Sciences and Maritime Engineering.
Addressing this challenge, the researchers investigated seven basalt lava flows at Kumbharli Ghat in Maharashtra’s Western Ghats. The findings are presented in the research paper titled “Characterising the Architecture of Deccan Basalt Flows for Subsurface CO2 Storage: A 3D Digital Outcrop Analogue Approach”, published in Marine Geoscience and Energy Resources.
The study marks the first use of drone-based photogrammetry to map individual lava flows in the Deccan basalt region. This technique combines photographs taken from different positions to reconstruct a three-dimensional model of the landscape.
Discussing its significance, Professor Khanna added,
“This is the first time such an outcrop-analogue approach has been used to quantitatively assess Deccan basalt. By combining detailed mapping of individual lava flows, including their boundaries, thickness, and shape, with rock analysis, the study provides the first systematic datasets of their kind for the Deccan basalt region, documenting variations in their structure. These insights offer a way to investigate how such variations influence fluid movement underground, where these complex structures are difficult to explore using conventional approaches.”
These findings are particularly relevant because basalt’s ability to facilitate mineralisation depends on several factors, including the availability of reactive minerals, the pathways through which fluids travel, and interactions between CO2 and the surrounding rock. Given these complexities, individual basalt formations must be assessed on their own merits rather than treated as uniform underground reservoirs. Yet, only a handful of studies have investigated how these processes operate under subsurface conditions in Deccan basalt and what this means for its suitability for CO2 storage.
Looking ahead, the datasets generated through this study can serve as a starting point for further investigations beyond the area examined.
“For us, an important outcome of this research is that these datasets can help other researchers better understand and model basalt formations underground. We hope this work will contribute to international efforts to explore geological CO2 storage as part of the wider response to climate change and energy transition. Scientific collaborations across countries can help build the shared knowledge needed to work towards a more sustainable future,” said lead author Debasmita Datta, a PhD student in the Department of Earth Sciences.
Together, these findings strengthen the scientific basis for assessing Deccan basalt for long-term CO2 storage, laying the groundwork for future studies in India and contributing to international efforts towards a lower-carbon future.
