Mounds formed by filamentous microbes and phylloid algae. Phylloid algae are loosely accumulated and supported by micritic encrustations that were formed by filamentous microbes. The filamentous microbes growing perpendicularly to the phylloid algal surfaces produced concentrated areas of peloids-A. The spaces between the phylloid algal-microbial frameworks were filled with concentrated areas of peloids-B (peloid-B aggregations) oriented perpendicular to the phylloid algae surfaces.