Vesicular Basalts as a Niche for Microbial Life

Abstract

The ongoing discovery of traces of microbial communities in locations on Earth where conditions are, or were, hostile to life suggests that unknown microbial ecosystems and habitats are yet to be detected. Volcanic environments on the ocean floor provide an important potential habitat for microbial life. Evidence of microbial activity and traces within the primary glassy rinds of basalts have revealed a highly complex microhabitat. Recent findings demonstrate that microbial activity and biodiversity in sub-seafloor volcanic rocks are also more differentiated than previously recognized. In addition to the glassy rinds of subsea pillow basalts, microbial ecosystems that have the potential to preserve traces of life in the geological record have been recognized in vesicular basalts. Here, we present a brief review of the evidence for endolithic microorganisms in volcanic basaltic rocks with an emphasis on the relatively poorly studied vesicular basalts that host microbial ecosystems. These types of habitats are of particular interest in the search for life on rocky, water-bearing terrestrial planets.