Microbial mat
![The cyanobacterial-algal mat, salty lake on the White Sea seaside](/Images/godic/202501/27/Cyanobacterial-algal_mat3928.jpg")
![Stromatolites are formed by some microbial mats as the microbes slowly move upwards to avoid being smothered by sediment.](/Images/godic/202501/27/Stromatolites_in_Sharkbay3928.jpg")
![Wrinkled Kinneyia-type sedimentary structures formed beneath cohesive microbial mats in peritidal zones.[10] The image shows the location, in the Burgsvik beds of Sweden, where the texture was first identified as evidence of a microbial mat.[11]](/Images/godic/202501/27/Runzelmarken3928.jpg")
![Kinneyia-like structure in the Grimsby Foramtion (Silurian) exposed in Niagara Gorge, New York.](/Images/godic/202501/27/Kinneyia_Grimsby_Silurian_Niagara_Gorge3928.jpg")
A microbial mat is a multi-layered sheet of microorganisms, mainly bacteria and archaea. Microbial mats grow at interfaces between different types of material, mostly on submerged or moist surfaces, but a few survive in deserts. They colonize environments ranging in temperature from –40 °C to 120 °C. A few are found as endosymbionts of animals.