The response of stromatolites to seismic shocks: Tomboliths from the Palaeoproterozoic Chaibasa Formation, E India
MetadataShow full item record
It is demonstrated here for the first time how Palaeoproterozoic stromatolites survived seismic disturbance of their substrate. The stromatolites under study could have been cyanobacteria or any other photoautotrophic microbes, which formed mats that covered a substrate of very fine-grained sandstones and mudstones of the Chaibasa Fm. in eastern India. The sediments represent a shelf environment. The local abundance of the stromatolites suggests that the low-energy environment formed a suitable habitat. The common phases of tectonic quiescence were, however, occasionally interrupted by seismic shocks. These were sufficiently strong to deform the mat layers, the lower parts of which might already have been (semi-) consolidated. The mats became partly folded, partly faulted, and already consolidated parts of the stromatolite layers broke off. This can be deduced from the angular shapes of part of the broken-off fragments. It appears, however, that part of these fragments were still sufficiently soft to become rounded and deformed by rolling over the seafloor, probably under the influence of tidal currents. When come to rest, these fragments served as a new substrate for new generations of the micro-organisms. These micro-organisms thus survived by continued growth on the reworked fragments and built up new stromatolites that may show an ‘angular disconformity’ with the stromatolites of their substrate. It thus is shown that stromatolites have an adequate response to a sudden disturbance of their habitat, and that they survive earthquakes by colonization of broken-off fragments. We call the ‘healed’ fragments ‘tomboliths’ (tumbled stones).
This open access article is distributed under the Creative Commons license http://creativecommons.org/licenses/by-nc-nd/4.0/
Showing items related by title, author, creator and subject.
Tube fossils from gossanites of the Urals VHMS deposits, Russia: Authigenic mineral assemblages and trace element distributionsAyupova, N.; Maslennikov, V.; Tessalina, Svetlana; Shilovsky, O.; Sadykov, S.; Hollis, S.; Danyushevsky, L.; Safina, N.; Statsenko, E. (2015)© 2016.The occurrence, types, morphology, and mineralogical characteristics of tube microfossils were studied in gossanites from twelve VHMS deposits of the Urals. Several types of tube microfossils were recognized, ...
Jahnert, Ricardo; Collins, Lindsay (2011)Microbial deposits at Shark Bay, Australia constitute one of the largest and most diverse modern occurrences around the world. The microbial carbonate system has developed in response to environmental change from near ...
Collins, Lindsay; Jahnert, Ricardo (2014)Three decades after declaration of World Heritage status for Shark Bay new research findings are being reported on the specialised microbial habitats that characterise its hypersaline settings, the composition of microbial ...