Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/4999
AuthorsCalderoni, G.* 
Di Giovambattista, R.* 
Burrato, P.* 
Ventura, G.* 
TitleA seismic sequence from Northern Apennines (Italy) provides new insight on the role of fluids in the active tectonics of accretionary wedges
Issue DateApr-2009
Series/Report no.1-2/281 (2008)
DOI10.1016/j.epsl.2009.02.015
URIhttp://hdl.handle.net/2122/4999
Keywordsseismicity
fluids
accretionary wedge
thrust
geodynamics
Northern Apennines
Subject Classification04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology 
04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution 
04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics 
04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis 
AbstractWe analyze a seismic sequence which occurred in 2000 along the Northern Apennines accretionary wedge (Italy). The sequence developed within the Cretaceous–Triassic limestones of the tectonic wedge, where methane-rich and oil reservoirs are stored. Ruptures mainly developed on WNW–ESE striking thrusts. The compressive stress field is consistent with that acting at regional scale in Northern Apennines. Seismic parameters indicate that fluids are involved in the seismogenic process. The amplitudes of the P and S phases and data from some stations evidence a P to S conversion within Vp/Vs=2.1 layer. The attenuation properties of crust show a higher attenuation zone located west of the epicentral cloud. Eight hundred aftershocks delineate a sub-vertical cloud of events between 7 and 14 km depth. The space–time evolution of the aftershocks is consistent with a diffusive spreading (diffusivity=1.9 m2/s) along vertically superimposed thrusts. Diffusion also controls the time evolution of the sequence. Fluid pressure is estimated to be roughly equal to the vertical, lithostatic stress. The overpressure within reservoirs develops by tectonic compaction processes. The fluids upraise along sub-vertical fractures related to the shortening of the wedge. The 2000 sequence occurred in an area that separates a thermal and deeper petroleum system from a shallower biogenic system. The divider of these systems controls the attenuation properties of the crust. The fluid–rock interaction at seismogenetic depth is related to hydrothermal processes more than to compaction. In accretionary wedges, seismicity activating superimposed thrusts may drive methane and oil upraising from the upper crust.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
Calderoni_etal_revised.pdfCorrected manuscript5.81 MBAdobe PDFView/Open
Calderoni_etal_2009_EPSL.pdfPrinted paper1.84 MBAdobe PDFView/Open    Request a copy
Show full item record

Page view(s)

149
checked on Apr 23, 2017

Download(s)

688
checked on Apr 23, 2017

Google ScholarTM

Check

Altmetric