Microbially induced sedimentary structures (MISS) are primary

sedimentary structures Sedimentary structures include all kinds of features in sediments and sedimentary rocks, formed at the time of deposition. Sediments and sedimentary rocks are characterized by bedding, which occurs when layers of sediment, with different parti ...

formed by the interaction of

microbes A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

with sediment and physical agents of erosion, deposition, and transportation. The structures commonly form when

microbial mat A microbial mat is a multi-layered sheet or biofilm of microbial colonies, composed of mainly bacteria and/or archaea. Microbial mats grow at interfaces between different types of material, mostly on submerged or moist surfaces, but a few surviv ...

s (which may comprise

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

protozoa Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically ...

ns,

archaea Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even thou ...

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

) are preserved in the sedimentary geological record. There are 17 main types of macroscopic and microscopic MISS.Noffke, N., 2010, Microbial Mats in Sandy Deposits from the Archean Era to Today: Springer Verlag, Heidelberg, 193 p. Of those, wrinkle structures and microbial mat chips are the most abundant in the fossil record. Other MISS include sinoidal structures, polygonal oscillation cracks, multidirected ripple marks, erosional remnants and pockets, or gas domes. Although these structures have only recently been named and systematically described, links between microbes and distinctive structures in sediments and sedimentary rocks have been suggested by several early workers. MISS have been identified in beds formed in the

Archean The Archean ( , also spelled Archaean or Archæan), in older sources sometimes called the Archaeozoic, is the second of the four geologic eons of Earth's history of Earth, history, preceded by the Hadean Eon and followed by the Proterozoic and t ...

and may be the oldest complete

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

. In the

Ediacaran The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last ...

period, they are often associated with the preservation of fossils of the

Ediacara biota The Ediacaran (; formerly Vendian) biota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (). These were enigmatic tubular and frond-shaped, mostly sessile, organis ...

; subsequent to this point their prevalence declines as a result of the Agronomic revolution A number of criteria have been proposed for recognising genuinely biological structures, and discriminating them from similar-looking features that can arise through geological processes. These relate to the extent of metamorphism to which the rocks have been subjected; their stratigraphic position with respect to sea-level; their depositional environment; their relationship to ancient hydraulics; and their texture. Individual studies on microbial mat-induced sedimentary structures are summarized and illustrated in several recent books, including ''Atlas of microbial mat features preserved in the siliciclastic rock record'' and ''Microbial Mats in Siliciclastic Depositional Systems Through Time''.Noffke, N. and Chaftez, H., 2012, Microbial Mats in Siliciclastic Depositional Systems Through Time: SEPM Special Publication 101. According to a study on the planet

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

, there may be sandstone beds, associated with the Gillespie Lake Member of Yellowknife Bay, visited by the ''Curiosity'' rover, that are similar to MISS on Earth.

References

{{DEFAULTSORT:Microbially Induced Sedimentary Structure Sedimentary structures

See also

References