TAILIEUCHUNG - Microbially induced sedimentary structures in evaporite–siliciclastic sediments of Ras Gemsa sabkha, Red Sea Coast, Egypt

The coastal sabkha in Ras Gemsa, Red Sea coast with its colonizing microbial mats and biofilms was investigated. The sabkha sediments consist mainly of terrigenous siliciclastic material accompanied by the development of evaporites. Halite serves as a good conduit for light and reduces the effect of intensive harmful solar radiation, which allows microbial mats to survive and flourish. The microbial mats in the evaporite–siliciclastic environments of such sabkha display distinctive sedimentary structures (microbially induced sedimentary structures), including frozen multidirected ripple marks, salt-encrusted crinkle mats, jelly roll structure, and petee structures. Scanning electron microscopy of the sediment surface colonized by cyanobacteria revealed that sand grains of the studied samples are incorporated into the biofilm by trapping and binding processes. Filamentous cyanobacteria and their EPS found in the voids in and between the particles construct a network that effectively interweaves and stabilizes the surface sediments. In advanced stages, the whole surface is covered by a spider web-like structure of biofilm, leading to a planar surface morphology. Sabkha with its chemical precipitates is a good model for potential preservation of life signatures. It is worthy to note that the available, published works on the subject of the present work are not numerous. | Microbially induced sedimentary structures in evaporite–siliciclastic sediments of Ras Gemsa sabkha, Red Sea Coast, Egypt

• Sinh học
• Coastal sabkha
• Microbial mats
• Microbially induced sedimentary structures
• Evaporite–siliciclastic sediments
• Ras Gemsa sabkha
• Red Sea Coast
• Scylla serrata
• Sexual secondary characters
• Red sea
• Sudanese red sea coast
• Length weight relationship
• Journal of Earth Sciences
• Bioerosional structures
• Coral reefs
• Saudi Arabia
• Oichnus paraboloides
• Caulostrepsis taeniola
• Red tide
• Algal bloom
• Diplopsalis lenticula
• Euglena acusformis
• Eutreptia lanowii
• Pyramimonas orientalis
• Earth sciences
• Fluviomarine transition
• Arid microtidal coasts
• Washover deposits
• Deltaic coasts
• Soft sediment deformation
• Wadi Al Hamd