By: Cassidy Delamarter, University Communications and Marketing
Through the intricate study of lava tubes, which are caves formed following volcanic eruptions when lava cools down, an international team of researchers has uncovered clues about Earth鈥檚 ancient environments that could be significant in the search for life on Mars. Bogdan P. Onac, professor in the USF School of Geosciences, collaborated with researchers from Portugal, Spain and Italy to shed light on how lava tubes may serve as valuable analogs for Martian caves and the search for extraterrestrial life.
Concert hall in Jameos del Agua, part of La Corona lava tube system in Lanzarote, Spain.
On the Spanish island of Lanzarote, just west of North Africa, the team explored six lava tubes to gather mineral deposits. Some of the tubes are so large, they are used to host underground concerts. 鈥淲hile the lava tubes on Lanzarote were discovered several years ago, we are the first to complete such a detailed study of minerals and microorganisms,鈥� Onac said.
In the study, published in , Onac and the team used a range of advanced molecular, isotopic and mineralogical techniques to examine the deposits and create a comprehensive understanding of the minerals they held. They learned the volcanic rock in the lava tubes created a protective environment that helped shield the minerals and organic compounds from weathering, ultimately preserving the minerals as records of past ecosystems.
The team found preserved biosignatures, including calcium and sodium sulfates. This discovery indicates microbial activity and microorganisms, such as bacteria, were once active in the caves.
White microbial-like colonies on the lava tube substrate.
鈥淭his 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,鈥� Onac said.
Given that Martian lava tubes are similarly shielded and likely contain sulfate-rich minerals, they may also hold signs of past microbial life, giving us clues about potential life beyond Earth. The findings may significantly impact the way scientists approach planetary exploration, particularly for upcoming missions aimed at studying the habitability of Mars.
The team will publish several additional studies on these lava tubes in the coming months and they are also planning to examine newly formed lava tubes in Iceland.