Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA.
Nat Commun. 2021 May 24;12(1):3037. doi: 10.1038/s41467-021-23006-1.
Microbialites accrete where environmental conditions and microbial metabolisms promote lithification, commonly through carbonate cementation. On Little Ambergris Cay, Turks and Caicos Islands, microbial mats occur widely in peritidal environments above ooid sand but do not become lithified or preserved. Sediment cores and porewater geochemistry indicated that aerobic respiration and sulfide oxidation inhibit lithification and dissolve calcium carbonate sand despite widespread aragonite precipitation from platform surface waters. Here, we report that in tidally pumped environments, microbial metabolisms can negate the effects of taphonomically-favorable seawater chemistry on carbonate mineral saturation and microbialite development.
微生物岩在环境条件和微生物代谢促进石化作用的地方堆积，通常通过碳酸盐胶结作用。在特克斯和凯科斯群岛的小安伯格里斯礁，微生物席广泛存在于潮上环境中的鲕粒砂中，但不会石化或保存下来。沉积物岩芯和孔隙水地球化学表明，尽管来自台地表面水的方解石广泛沉淀，但好氧呼吸和硫化物氧化会抑制石化作用并溶解碳酸钙砂。在这里，我们报告说，在潮汐抽吸环境中，微生物代谢可以抵消有利于埋藏学的海水化学对碳酸盐矿物饱和度和微生物岩发育的影响。
