Columnar Jointing in the Deccan Continental Flood Basalt, India: Implications as a Martian Analogue

The continental flood basalt on Earth and the extensive flood basalt provinces on Mars are well recognised for their prominent surface manifestation, which offer valuable insights into the planet’s interior activity and evolution. Mars’s volcanic provinces are significantly larger than those on Earth; however, the volcanic landforms, particularly the columnar jointing in basalt flows, show some remarkable morphological resemblances. The Deccan trap basalts are characterised by a tholeiite composition with typical iron‑rich trend similar to that of Martian basalts. Within the Deccan volcanic province, the columnar jointing includes both colonnade and entablature jointing facies with a more or less consistent hexagonality index (XN:1.34), reflecting its maturity index. A higher cooling rate (0.29 °C/h) contributes to the formation of entablature as compared to colonnade. The morphology of the colonnade is influenced by a uniform cooling mechanism corroborated with the liquid water infiltration during the emplacement of lava. Thus, the columnar jointing in basalt provides insights into the paleoenvironment during lava emplacement. The morphology of columnar basalt on Mars is mainly gained through remote sensing and in situ rover observations. The presence of both colonnade and entablature on Martian columnar basalt also indicates that water was likely prevalent, possibly flooding or ponding during the lava’s emplacement. In comparative planetology, incorporating new, potential terrestrial analogue materials remains a top priority to validate orbiter data and to strategise for future planetary exploration.