The team, including experts from Portugal, Spain, and Italy, focused on six lava tubes on Lanzarote, a Spanish island near North Africa. Known for their substantial size - sometimes hosting underground events - the tubes offered rich samples of mineral deposits.

"While the lava tubes on Lanzarote were discovered several years ago, we are the first to complete such a detailed study of minerals and microorganisms," Onac said.

The research, published in 'Communications Earth and Environment', employed sophisticated molecular, isotopic, and mineralogical methods to analyze these deposits. It was found that volcanic rock within the tubes provided a natural shield, preserving minerals and organic compounds from erosion. This environment maintained a record of ancient ecosystems, including biosignatures such as calcium and sodium sulfates, indicating previous microbial activity.

"This study adds to our understanding of geological and environmental changes on Earth and highlights lava tubes as potential refuges for microbial life, holding significant implications for astrobiology, particularly in identifying biosignatures on Mars and other celestial bodies," Onac said.

The implications extend to Martian exploration, as similar lava tubes on Mars could protect sulfate-rich minerals and potential biosignatures of ancient life. These findings could influence future planetary missions aimed at assessing the habitability of Mars.

The research team plans to release further studies on these caves and will soon explore new lava tubes in Iceland.

Research Report:Decoding organic compounds in lava tube sulfates to understand potential biomarkers in the Martian subsurface