Microbial and diagenetic steps leading to the mineralisation of Great Salt Lake microbialites.

ABSTRACT: Microbialites are widespread in modern and fossil hypersaline environments, where they provide a unique sedimentary archive. Authigenic mineral precipitation in modern microbialites results from a complex interplay between microbial metabolisms, organic matrices and environmental parameters. Here, we combined mineralogical and microscopic analyses with measurements of metabolic activity in order to characterise the mineralisation of microbial mats forming microbialites in the Great Salt Lake (Utah, USA). Our results show that the mineralisation process takes place in three steps progressing along geochemical gradients produced through microbial activity. First, a poorly crystallized Mg-Si phase precipitates on alveolar extracellular organic matrix due to a rise of the pH in the zone of act

SUBMITTER: Pace A 

PROVIDER: S-EPMC4985759 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature