Analogue and numerical modeling of normal fault patterns produced due to slip along a detachment zone

Exadaktylos, GE; Vardoulakis, I; Stavropoulou, MC; Tsombos, P

dc.contributor.author	Exadaktylos, GE	en
dc.contributor.author	Vardoulakis, I	en
dc.contributor.author	Stavropoulou, MC	en
dc.contributor.author	Tsombos, P	en
dc.date.accessioned	2014-03-01T01:18:39Z
dc.date.available	2014-03-01T01:18:39Z
dc.date.issued	2003	en
dc.identifier.issn	0040-1951	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15134
dc.subject	Analogue experiments	en
dc.subject	Detachment zone	en
dc.subject	Extension	en
dc.subject	Graben	en
dc.subject	Gulf of Corinth	en
dc.subject	Normal faults	en
dc.subject	Numerical model	en
dc.subject.classification	Geochemistry & Geophysics	en
dc.subject.other	analog model	en
dc.subject.other	detachment fault	en
dc.subject.other	extension	en
dc.subject.other	fault propagation	en
dc.subject.other	fault slip	en
dc.subject.other	graben	en
dc.subject.other	normal fault	en
dc.subject.other	numerical model	en
dc.subject.other	Mediterranean Sea	en
dc.title	Analogue and numerical modeling of normal fault patterns produced due to slip along a detachment zone	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.tecto.2003.08.005	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.tecto.2003.08.005	en
heal.language	English	en
heal.publicationDate	2003	en
heal.abstract	In this paper, we investigate normal fault patterns produced by the sliding motion along a gently dipping normal fault by using analogue model tests and numerical modeling. The motivation for this study was offered by microseismic test data that indicate the existence of an active low-angle shear zone at a depth of 9 - 11 km in the extensional region of high seismic activity of the Gulf of Corinth (Greece). Both modeling techniques seem to support the hypothesis that the system of high-angle normal faults that are responsible for the final asymmetrical graben formation initiate at the tip of the active basal detachment nearest to the free surface. The normal faults propagate upwards with progressive sliding of the inclined basal plane, resulting in a first phase of symmetrical graben configuration that is delimited by a main synthetic fault and an antithetic fault forming a Rankine zone. Subsequent sliding on the inclined base induces a family of secondary antithetic normal faults, which are responsible for the asymmetry of the failure pattern and the diffusive character of deformation in that area. Shear deformation is more intense and localized along the synthetic normal fault than along the antithetic faults. Elaboration on the analogue test results has led to the phenomenological relations among four main parameters that describe the geometry of grabens, namely, (i) the width and (ii) the maximum subsidence of the graben, (iii) the dip angles of the conjugate normal faults, and (iv) the amount of sliding along the low-angle normal fault. However, analogue models do not produce the system of synthetic faults that is observed in the Gulf of Corinth. The effects of both friction angle variation along the detachment base and of the constitutive behavior of the model material on the configuration of the final structural pattern were also studied with a series of numerical continuum models. It was found that (a) the fault pattern of the Gulf of Corinth may be reproduced with either a strain-softening material with low elastic modulus or a constant strength material, and (b) two consecutive grabens, such as those of Gulfs of Corinth and Evia, may also be reproduced by an appropriate combination of variation of dip and frictional properties along the hypothesized detachment zone. (C) 2003 Elsevier B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Tectonophysics	en
dc.identifier.doi	10.1016/j.tecto.2003.08.005	en
dc.identifier.isi	ISI:000186806400007	en
dc.identifier.volume	376	en
dc.identifier.issue	1-2	en
dc.identifier.spage	117	en
dc.identifier.epage	134	en