Cyanobacterial calcite cementation in a tidal channel of the Bay of Cadiz Natural Park

A study of the carbonated crust located in a tidal channel close to a hypersaline tidal lagoon of the Nature area of the Bay of Cádiz has been done. A textural, mineralogical, and an experimental study, including O2 y pH measurements have been conducted during a period of a month and a tidal cycle in four different locations along the channel. The results of the mineralogical and textural study and those from the microelectrodes, show how the photosynthetic activity of biofilms dominated by cyanobacteria and diatoms growing in the sediment surface seems to control the calcite precipitation on the intertidal sediments. Although bacterial remains are rarely preserved in beachrocks, this study shows how bacterial activity should be taken into account in beachrock development in coastal environmentsMinisterio de Educación y Ciencia, proyecto MICROBENTOS (CTM2006-04015/MAR