The lithospheric structure of the Western Carpathian–Pannonian Basin region based on the CELEBRATION 2000 seismic experiment and gravity modelling Alasonati Tašárová a, ⁎, J.C. Afonso b, 1 , M. Bielik c,d , H.-J. Götze a , J. Hók e a Institut für Geowissenschaften, Christian-Albrechts-Universität zu Kiel, Germany b Institute of Earth Sciences J. Almera, Department of Geophysics and Tectonics, Barcelona, Spain c Department of Applied and Environmental Geophysics, Faculty of Natural Sciences, Bratislava, Slovakia d Geophysical Institute of the Slovak Academy of Sciences, Bratislava, Slovakia e Department of Geology and Paleontology, Faculty of Natural Sciences, Bratislava, Slovakia abstract article info Article history: Received 27 February 2008 Received in revised form 30 April 2009 Accepted 4 June 2009 Available online 12 July 2009 Keywords: Gravity modeling Bouguer anomaly Lithospheric structure Western Carpathians Pannonian Basin system Xenoliths The lithospheric structure of the Western Carpathian–Pannonian Basin region was studied using 3-D model- ling of the Bouguer gravity anomaly constrained by seismic models and other geophysical data. The thermal structure and density distribution in the shallow upper mantle were also estimated using a combination of petrological, geophysical, and mineral physics information (LitMod). This approach is necessary if the more complicated structure of the Pannonian Basin is to be better constrained. As a result, we have constructed the first 3-D gravity model of the region that combines various geophysical datasets and is consistent with petro- logical data. The model provides improved estimates of both the density distribution within the lithosphere and the depth to major density discontinuities. We present new maps of the thickness of major sedimentary basins and of the depth to the Moho and the lithosphere–asthenosphere boundary. In our best-fitting model, the Pannonian Basin is characterised by extremely thin crust and lithospheric mantle, both of which have low density. A low-density uppermost asthenospheric mantle layer is also included at depths of 60–100 km. The Western Carpathians have only a thin crustal root and moderate densities. In contrast, the European Platform and Eastern Alps are characterised by lithosphere that is considerably thicker and denser. This inference is also supported by stripped gravity anomalies from which sediment, Moho and asthenospheric gravity contributions have been removed. These residual anomalies are characteristically low in the Western Carpathian–Pannonian Basin region, which suggests that both the ALCAPA and Tisza–Dacia microplates are ‘exotic terranes’ that are markedly different to the European Platform. © 2009 Elsevier B.V. All rights reserved. 1. Introduction The Western Carpathians comprise the westernmost part of the arcuate Carpathian Mountains, extending over 1300 km through Austria, Slovakia, Czech Republic, Poland, Ukraine, Hungary and Romania (Fig. 1). The Carpathians were formed in the Alpine–Carpathian– Pannonian region during the Alpine orogenesis. They record a complex tectonic history, involving extrusion of microplates, ocean closure, sub- duction, slab rollback, slab detachment and asthenospheric upwelling (Bielik et al., 2004). Although this area has been subject to geological, geophysical and petrological investigations for decades (Balla, 1987; Royden and Horváth, 1988; Praus et al., 1990; Csontos et al., 1992; Downes et al., 1992; Tari et al., 1993; Tomek and Hall, 1993; Cermák, 1994; Márton and Fodor, 1995; Linzer,1996; Meulenkamp et al.,1996; Plašienka et al., 1997; Rosenbaum et al., 1997; Szafián et al., 1997; Goes et al., 1999; Lenkey, 1999; Kováč, 2000; Wortel and Spakman, 2000; Embey-Isztin et al., 2001; Sperner et al., 2004; Knapp et al., 2005), certain aspects of its evolution remain unclear. In 2000, a large-scale international project, the Central European Lithospheric Experiment based on Refraction (CELEBRATION 2000) (Guterch et al., 2003), was conducted in Central Europe. The seismic data (refraction and also wide-angle reflection) were collected along 17 profiles with a total length of 8900 km. Based on, the results from profiles CEL01, CEL02, CEL03, CEL04, CEL05, CEL09 and CEL 10 (Malinowski et al., 2005; Janik et al., 2005; Grad et al., 2006; Hrubcová et al., 2005; Środa et al., 2006; Růžek et al., 2007), a preliminary 3-D density model of the Western Carpathians and the Pannonian Basin was developed using combined seismic–gravity interpretation (Ala- sonati Tašárová et al., 2008). However, the densities in the uppermost mantle used in this model were only estimated by means of simple P- wave parameterisations and general thermal anomaly trends. No petrological or thermodynamic constraints on the mineralogy of the uppermost mantle were considered. Since the influence of density on gravity field and topography modelling is of first order importance, a realistic density distribution, Tectonophysics 475 (2009) 454–469 ⁎ Corresponding author. Tel.: +49 431 8803912. E-mail address: tasarova@geophysik.uni-kiel.de (A. Tašárová). 1 Now at GEMOC ARC Key Centre, Department of Earth Sciences, Macquarie University, Sydney, Australia. 0040-1951/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.tecto.2009.06.003 Contents lists available at ScienceDirect Tectonophysics journal homepage: www.elsevier.com/locate/tecto