Obtaining constraints on maximum earthquake energy from fossil geological evidence has a primary importance for complementing historical information toward the proper mitigation of seismic hazard in a region. In this paper, we describe a newly discovered extensional fault zone in the western L'Aquila basin (Italy), associated with large paleofluidization structures. Paleofluidization-bearing Calabrian sediments provide evidence for very shallow burial from mineralogical, organic matter thermal maturity, and flat dilatometer test data, whereas density of organic matter shows anomalously high values. We propose that all these pieces of information can be reconciled into a paleoseismological scenario where sediment liquefaction and fluidization in early middle Pleistocene times, as well as dewatering and overconsolidation, were coseismically triggered by strong earthquakes with magnitude approaching or slightly exceeding 7.0
Evidence of strong Quaternary earthquakes in the epicentral area of the April 6th 2009 L’Aquila seismic event from sediment paleofluidization and overconsolidation / F., Storti; Aldega, Luca; F., Balsamo; S., Corrado; F., Del Monaco; L., Di Paolo; M., Mastalertz; P., Monaco; M., Tallini. - In: JOURNAL OF GEOPHYSICAL RESEARCH. - ISSN 2156-2202. - STAMPA. - 118:7(2013), pp. 3767-3784. (Intervento presentato al convegno EGU General Assembly 2012 tenutosi a Vienna nel 22-27 Aprile 2012) [10.1002/jgrb.50254].
Evidence of strong Quaternary earthquakes in the epicentral area of the April 6th 2009 L’Aquila seismic event from sediment paleofluidization and overconsolidation
ALDEGA, LUCA;
2013
Abstract
Obtaining constraints on maximum earthquake energy from fossil geological evidence has a primary importance for complementing historical information toward the proper mitigation of seismic hazard in a region. In this paper, we describe a newly discovered extensional fault zone in the western L'Aquila basin (Italy), associated with large paleofluidization structures. Paleofluidization-bearing Calabrian sediments provide evidence for very shallow burial from mineralogical, organic matter thermal maturity, and flat dilatometer test data, whereas density of organic matter shows anomalously high values. We propose that all these pieces of information can be reconciled into a paleoseismological scenario where sediment liquefaction and fluidization in early middle Pleistocene times, as well as dewatering and overconsolidation, were coseismically triggered by strong earthquakes with magnitude approaching or slightly exceeding 7.0I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.