marine coarse sand surface grab Raw sequence reads

Ooids are sedimentary grains distributed widely in the geological record, yet how they form, andwhether microbes contribute to their formation, is still debated. This limits our understanding ofthe 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.

鲕粒（ooids）是广泛分布于地质记录中的沉积颗粒，但其形成机制以及微生物是否参与其形成过程，至今仍存在争议。这一现状限制了我们对鲕粒地质意义的认知，以及其作为古代沉积岩中古环境记录载体的应用价值。为此，我们针对巴哈马卡特岛鸽子礁的表层鲕粒砂开展研究，分析其相关微生物群落组成与分子脂质生物标志物（molecular lipid biosignatures）。采样沿断面进行，覆盖从浅水区湍急的激浪带至相对平静的深水区域。我们还将覆盖颗粒表层的生物膜与有机质结合的脂质，与鲕粒皮层内部结合的脂质进行了对比分析。