Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/582
AuthorsPittarello, L.* 
Di Toro, G.* 
Bizzarri, A.* 
Hadizadeh, J.* 
Pennacchioni, G.* 
TitleSeismic energy partitioning inferred from pseudotachylyte-bearing faults (Gole Larghe Fault, Adamello batholith, Italy)
Issue Date4-Dec-2005
URIhttp://hdl.handle.net/2122/582
KeywordsEarthquake dynamics
Dynamics and mechanics of faulting
Fractures and faults
Microstructures
Structural goelogy
Subject Classification04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology 
AbstractFracture energy EG (the energy used for expanding a rupture surface area) is the fraction of work during seismic faulting that is required for creation of (i) new surfaces in the slip zone, and (ii) damage zone in the wall rocks. Partitioning of the earthquake energy between EG and frictional heat EH, determines the features of the rupture propagation and the mechanical behavior of the fault. The cataclastic microstructures associated with pseudotachylyte (solidified clast-laden friction-induced melt produced during coseismic slip) veins might contain information about the partitioning. In this preliminary study we used microstructural observations on pseudotachylytes from the Gole Larghe Fault zone (Southern Alps, Italy) to determine both EH and EG. The EH for unit fault surface area is estimated from pseudotachylyte vein thickness 2w. The energy required to produce friction melt is EH = [(1- f) H+ cP(Tm-Thr)]r 2w where f is the volume ratio of lithic clasts within the pseudotachylyte, H is the latent heat of fusion, cP is the specific heat at constant pressure, (Tm-Thr) is the difference between initial melt temperature and host rock temperature and r is the density. The EG is estimated by multiplying the newly created grain surface per unit of fault area by the specific surface energy (J m-2). In fact the studied pseudotachylyte vein contains plagioclase clasts displaying a characteristic internal fragmentation not observed in the host rock. This indicates a direct association between newly created grain surfaces and the seismic rupture process via pseudotachylyte production. It follows that pseudotachylytes might yield information on the energy partitioning between EG and EH.
Appears in Collections:Conference materials

Files in This Item:
File Description SizeFormat 
poster_AGU_SF.pdf2.31 MBAdobe PDFView/Open
Show full item record

Page view(s)

69
checked on May 24, 2017

Download(s)

208
checked on May 24, 2017

Google ScholarTM

Check