This wrinkled "elephant skin" texture is a feature formed from a non-stromatolite microbial mat. The image shows the location, in theBurgsvik beds ofSweden, where the texture was first identified as evidence of a microbial mat.[1]
Microbially induced sedimentary structures (MISS) are primarysedimentary structures formed by the interaction ofmicrobes with sediment and physical agents of erosion, deposition, and transportation.[2][3][4][5] The structures commonly form whenmicrobial mats (which may comprisebacteria,fungi,protozoans,archaea oralgae) are preserved in the sedimentary geological record.[6] There are 17 main types of macroscopic and microscopic MISS.[7] Of those, wrinkle structures[8] and microbial mat chips are the most abundant in the fossil record. Other MISS include sinoidal structures, polygonal oscillation cracks, multidirected ripple marks,[9] 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.[1][10][11][12] MISS have been identified in beds formed3,480 million years ago in theArchean[13][14] and may be the oldest completefossils onEarth.[7][13][14] In theEdiacaran period, they are often associated with the preservation of fossils of theEdiacara biota; subsequent to this point their prevalence declines as a result of theAgronomic revolution[7][15][16][17]
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.[6]
Individual studies on microbial mat-induced sedimentary structures are summarized and illustrated in several recent books, includingAtlas of microbial mat features preserved in the siliciclastic rock record[18] andMicrobial Mats in Siliciclastic Depositional Systems Through Time.[19]
^abNoffke, N. (2009). "The criteria for the biogeneicity of microbially induced sedimentary structures (MISS) in Archean and younger, sandy deposits".Earth-Science Reviews.96 (3):173–180.Bibcode:2009ESRv...96..173N.doi:10.1016/j.earscirev.2008.08.002.
^abcNoffke, N., 2010, Microbial Mats in Sandy Deposits from the Archean Era to Today: Springer Verlag, Heidelberg, 193 p.
^Hagadorn, J.W.; Bottjer, D.J. (1999). "Wrinkle structures: Microbially mediated sedimentary structures common in subtidal siliciclastic settings at the Proterozoic-Phanerozoic transition".Geology.25 (11):1047–1050.doi:10.1130/0091-7613(1997)025<1047:WSMMSS>2.3.CO;2.
^Noffke, N (1998). "Multidirected ripple marks arising from bacterial stabilization counteracting physical rework in modern sandy deposits (Mellum Island, southern North Sea)".Geology.26 (10):879–882.doi:10.1130/0091-7613(1998)026<0879:mrmrfb>2.3.co;2.
^Pratt, B.R., 2003, Stromatolites, in Middleton, G.V., ed., Encyclopedia of Sediments and Sedimentary Rocks: Boston, Kluwer Academic Press, p. 688-690.
^Gerdes, G. and Krumbein, 1987, Biolaminated deposits: Springer, Heidelberg, 169 p.
^Noffke, N.; Paterson, D. (2007). "Microbial interactions with physical sediment dynamics, and their significance for the interpretation of Earth's biological history".Geobiology.6 (1):1–4.doi:10.1111/j.1472-4669.2007.00132.x.PMID18380881.S2CID31284434.
^Schieber et al., eds., 2007, Atlas of microbial mat features preserved in the siliciclastic rock record: Elsevier, 324 p.
^Noffke, N. and Chaftez, H., 2012, Microbial Mats in Siliciclastic Depositional Systems Through Time: SEPM Special Publication 101.
^Nora, Noffke (February 14, 2015). "Ancient Sedimentary Structures in the <3.7 Ga Gillespie Lake Member, Mars, That Resemble Macroscopic Morphology, Spatial Associations, and Temporal Succession in Terrestrial Microbialites".Astrobiology.15 (2):169–192.Bibcode:2015AsBio..15..169N.doi:10.1089/ast.2014.1218.PMID25495393.
