Seismite

Seismites in the Upper Ordovician of northern Kentucky.

Seismite in the Upper Ordovician of northern Kentucky (closer view).

Seismites are sedimentary beds disturbed by seismic shaking. The German paleontologist Adolf Seilacher first used the term in 1969^[1] to describe a variety of post-depositional effects of seismic shocks on unconsolidated sediments. Today, the term describes both sedimentary beds deformed by seismic shaking and associated soft sediment deformation structures formed by shaking that may or may not remain confined to a stratigraphic layer (i.e., clastic dikes or sand volcanos).^[2] Several informal classification systems have been developed to distinguish seismites from soft sediment deformation features formed by non-seismic processes,^{[3][4][5][6][7][8][9][10][11][12]} though a formal, standardized system has not. Geologists use seismites to better understand the earthquake history of an area. If age and distribution can be determined, then recurrence interval and seismic hazard risk can be assessed.^{[13][14][15][16]}

See also

• Speleoseismite
• Soft-sediment deformation structures

References

1. ↑ Seilacher, A., 1969, Fault-graded beds interpreted as seismites, Sedimentology, 13, p. 15-159
2. ↑ Seilacher, A., 1984, Sedimentary structures tentatively attributed to seismic events, Marine Geology, 55, p. 1-12
3. ↑ Seilacher, A., 1969, Fault-graded beds interpreted as seismites, Sedimentology, 13, p. 15-159
4. ↑ Mills, P.C., 1983, Genesis and diagnostic value of soft-sediment deformation structures – a review, Sedimentary Geology, 35, p. 83-104
5. ↑ Groshong, R.H., 1988, Low-temperature deformation mechanism and their interpretation, GSA Bulletin, 100, p. 1329-1360
6. ↑ Allen, C.R., 1975, Geological criteria for evaluating seismicity, GSA Bulletin, 86, p. 1041-1057
7. ↑ Guiraud and Plaziet, 1993
8. ↑ Obermeier, S.F., 1996b, Use of liquefaction-induced features for paleoseismic analysis - an overview of how seismic liquefaction features can be distinguished from other features and how their regional distribution and properties of source sediment can be used to infer the location and strength of Holocene paleo-earthquakes, Engineering Geology, 44, p. 1-46
9. ↑ Greb, S.F.; Ettensohn, F.R.; Obermeier, S.F., 2002, Developing a classification scheme for seismites, GSA North-central & Southeastern Section Annual Meeting Abstracts with Programs
10. ↑ Wheeler, R.L., 2002, Distinguishing seismic from nonseismic soft-sediment structures: Criteria from seismic-hazard analysis, in Ettensohn, F.R.; Rast, N.; Brett, C.E. (editors), Ancient Seismites, GSA Special Paper, 359, p. 1-11
11. ↑ Obermeier, S.F.; Olson, S.M.; Green, R.A., 2005, Field occurrences of liquefaction-induced features: a primer for engineering geologic analysis of paleoseismic shaking, Engineering Geology, 76, p. 209-234
12. ↑ Montenat, C.; Barrier, P.; d'Estevou, P.O.; Hibsch, C., 2007, Seismites: An attempt at critical analysis and classification, Sedimentary Geology, 196, p. 5-30
13. ↑ Jewell and Ettensohn, 2004, An ancient seismite response to Taconian far-field forces: the Cane Run Bed, Upper Ordovician (Trenton) Lexington Limestone, Central Kentucky (USA),
14. ↑ Bachmann, G.H., Aref, M.A.M., 2005, A seismite in Triassic gypsum deposits (Grabfeld Formation, Ladinian), southwestern Germany, Sedimentary Geology, 180, p. 75–89, doi = 10.1016/j.sedgeo.2005.04.006
15. ↑ Jewell, H.E., Ettensohn, F.R., 2004, An ancient seismite response to Taconian far-field forces: the Cane Run Bed, Upper Ordovician (Trenton) Lexington Limestone, Central Kentucky (USA), Journal of Geodynamics, 37, p. 487–511, doi = 10.1016/j.jog.2004.02.017
16. ↑ Merriam, D.F., Neuhauser, K.R., 2009, Seismite Indicates Pleistocene Earthquake Activity in Ellis County, Kansas, Transactions of the Kansas Academy of Science, 112, p. 109–112, doi = 10.1660/062.112.0214