marine coarse sand surface grab Raw sequence reads. sand metagenome

Ooids are sedimentary grains distributed widely in the geological record, yet how they form, and whether microbes contribute to their formation, is still debated. This limits our understanding of the geological significance of ooids and their utility as recorders of paleoenvironments in ancient sedimentary rocks. To address this, we investigated the microbial community composition and molecular lipid biosignatures associated with surface oolitic sands at Pigeon Cay on Cat Island, the Bahamas. Samples were taken along a transect from the shallow, turbulent surf zone to calmer, deeper water. The lipids associated with biofilms and organic matter coating grain surfaces were also compared to lipids bound within ooid cortices.