[meteorite-list] RE: Article on paleo-Bolide porduced tsunamites/seismites

[Paul]

jonee (Elton) asked:

"Anyone have a link as to specifically what tsunamites 
and seismites are defined as?"

There is a definition of "tsunamite" in:

Shanmugam, G., 2006, The Tsunamite Problem. Journal 
of Sedimentary Research. vol. 76. DOI: 10.2110/jsr.2006.073

http://www.colorado.edu/geolsci/jsedr/Abstracts/may2006/ShanmugamAbs.pdf
http://www.colorado.edu/geolsci/jsedr/Abstracts/may2006/jsr76-5.html

The above abstract stated:

"The genetic term tsunamite is used for a potpourri 
of deposits formed from a wide range of processes 
(overwash surges, backwash flows, oscillatory flows, 
combined flows, soft-sediment deformation, slides, 
slumps, debris flows, and turbidity currents) related 
to tsunamis in lacustrine, coastal, shallow-marine, 
and deep-marine environments."

Although they are called "Tsunami Sand Deposits", pictures 
of coastal plain "tsunamites" created by the December Indian 
Ocean Tsunami can be seen in:

"The December 26, 2004 Indian Ocean Tsunami: Initial 
Findings on Tsunami Sand Deposits, Damage, and 
Inundation in Sri Lanka" at:

http://walrus.wr.usgs.gov/tsunami/srilanka05/tsunami_sand_deposit.html
http://walrus.wr.usgs.gov/tsunami/srilanka05/sand.html

and in "Tsunami deposits (figure 3: thickness of the deposits)" at:

http://perso.wanadoo.fr/raphael.paris/tsunami.htm

Another coastal tsunami deposit (tsunamite) from the 
1929 Grand Banks Earthquake found at Taylor's Bay on 
Newfoundland's southern coast can be seen at:

http://www.seismo.nrcan.gc.ca/damage/1929/1929tuttleresearch.php

 A definition of "seismite" can be found in "Developing a Classification
Scheme for Seismites" by Stephen F. Greb at:

http://gsa.confex.com/gsa/2002NC/finalprogram/abstract_32750.htm

This abstract for the 2002 North-Central Section (36th) and 
Southeastern Section (51st), Geological Society of America Joint 
Annual Meeting stated:

"The term "seismite" is presently used for many features and 
deposits of inferred seismic origin, each of which requires 
varying types and amounts of data to support a seismic 
interpretation."

One type of seismite is sediment that show disturbance / 
deformation, while it was still soft, caused by the ground 
shaking, which accompanies an earthquake. Some pictures 
of seismites can be found in "The Late Triassic seismite 
in Northern Ireland, southwest England and south Wales" at:

http://www.habitas.org.uk/larne/assortedseismites.html

A related article might be:

Walkden, G., J. Parker, and S. Kelley, 2002,  A Late Triassic 
Impact Ejecta Layer in Southwestern Britain. Science. vol. 298, 
no. 5601, pp. 2185-2188. DOI: 10.1126/science.1076249
http://www.sciencemag.org/cgi/content/short/298/5601/2185

The Entrada Sandstone contains soft sediment deformation 
features, which are argued to be impact-related seismites. 
This is discussed in:

Alvarez, W., E. Staley, D. O'Connor, and M. A. Chan, 1998,
Synsedimentary deformation in the Jurassic of southeastern 
Utah: A case of impact shaking? Geology. vol. 26, no. 7, 
pp. 579-582.  

http://eps.berkeley.edu/~platetec/125.pdf

a press release can be found at:

http://www.sciencedaily.com/releases/1998/10/981006073850.htm

Best

Paul

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