To illustrate the Neogene shortening distribution in the back-arc units of the Central Andes and to estimate the contribution of the shortening to crustal thickening, two balanced crustal cross sections have been constructed across the northern and southern branches of the Bolivian orocline. Total Neogene shortening, which varies from 191 to 231 km, is accommodated by a crustal duplex below the Cordillera Oriental, but is insufficient to produce the 70 km of crustal thickness evidenced by geophysical data below the Altiplano. The best explanation for this anomalous thickening seems to be crustal underplating by material tectonically eroded from the continental margin; this process probably caused the Altiplano uplift. The subduction of oceanic lithosphere coupled with this underplating and a brief episode of gravity spreading of the Altiplano constituted the driving forces that produced Neogene shortening and development of the. ' Central Andes.

Three-dimensional modelling tools are used with structural and palaeomagnetic analysis to constrain the tectonic history of part of the Dauphiné zone (external Western Alps). Four compressive events are identified, three of them being older than the latest Oligocene. Deformation D1 consists of W-SW directed folds in the Mesozoic cover of the study area. This event, better recorded in the central and southern Pelvoux massif, could be of Eocene age or older. Deformation D2 induced N-NW-oriented basement thrusting and affected the whole southern Dauphiné basement massifs south of the study area. The main compressional event in the study area (D3) was WNW oriented and occurred before 24 Ma under a thick tectonic load probably of Penninic nappes. The D2-D3 shift corresponds to a rapid transition from northward propagation of the Alpine collision directly driven by Africa-Europe convergence, to the onset of westward escape into the Western Alpine arc. This Oligocene change in the collisional regime is recorded in the whole Alpine realm, and led to the activation of the Insubric line. The last event (D4) is late Miocene in age and coeval with the final uplift of the Grandes Rousses and Belledonne external massifs. It produced strike-slip faulting and local rotations that significantly deformed earlier Alpine folds and thrusts, Tethyan fault blocks and Hercynian structures. 3D modelling of an initially horizontal surface, the interface between basement and Mesozoic cover, highlights large-scale basement involved asymmetric folding that is also detected using structural analysis. Both, Jurassic block faulting and basement fold-and-thrust shortening were strongly dependent on the orientation of Tethyan extension and Alpine shortening relative to the late Hercynian fabric. The latter's reactivation in response to oblique Jurassic extension produced an en-échelon syn-rift fault pattern, best developed in the western, strongly foliated basement units. Its Alpine reactivation occurred with maximum efficiency during the early stages of lateral escape, with tectonic transport in the overlying units being sub-perpendicular to it. IntroductionThe origin of the arcuate shape of the Western Alpine fold belt is still debated. Some models regard it as inherited either from the shape of the Jurassic margins (Lemoine et al. 1989) or from the shape of the Adriatic indenter (Coward & Dietrich 1989). Other authors propose that the arc was created during Alpine collision due to indentation and lateral escape (e.g. Tapponnier

In the last decades, municipal mergers have been one major element of local government reforms in Switzerland and beyond. In this article, we describe and analyze the political effects of this development. We use a quasi‐experimental setting to test the impact of municipal mergers on electoral participation. We find that in merged municipalities, the decrease in turnout is significantly stronger than in non‐merged municipalities. Further, the effect is more pronounced in relatively small localities. There is a temporal dimension to this effect—that is, turnout drops mainly in the first election after the first merger, but not so much after the second or third merger. Hence, the study provides a skeptical yet differentiated perspective on the democratic consequences of municipal mergers and points to further research avenues to develop a more comprehensive understanding of local government consolidation.

Three-dimensional modelling tools are used with structural and palaeomagnetic analysis to constrain the tectonic history of part of the Dauphiné zone (external Western Alps). Four compressive events are identified, three of them being older than the latest Oligocene. Deformation D1 consists of W-SW directed folds in the Mesozoic cover of the study area. This event, better recorded in the central and southern Pelvoux massif, could be of Eocene age or older. Deformation D2 induced N-NW-oriented basement thrusting and affected the whole southern Dauphiné basement massifs south of the study area. The main compressional event in the study area (D3) was WNW oriented and occurred before 24 Ma under a thick tectonic load probably of Penninic nappes. The D2-D3 shift corresponds to a rapid transition from northward propagation of the Alpine collision directly driven by Africa-Europe convergence, to the onset of westward escape into the Western Alpine arc. This Oligocene change in the collisional regime is recorded in the whole Alpine realm, and led to the activation of the Insubric line. The last event (D4) is late Miocene in age and coeval with the final uplift of the Grandes Rousses and Belledonne external massifs. It produced strike-slip faulting and local rotations that significantly deformed earlier Alpine folds and thrusts, Tethyan fault blocks and Hercynian structures. 3D modelling of an initially horizontal surface, the interface between basement and Mesozoic cover, highlights large-scale basement involved asymmetric folding that is also detected using structural analysis. Both, Jurassic block faulting and basement fold-and-thrust shortening were strongly dependent on the orientation of Tethyan extension and Alpine shortening relative to the late Hercynian fabric. The latter's reactivation in response to oblique Jurassic extension produced an en-échelon syn-rift fault pattern, best developed in the western, strongly foliated basement units. Its Alpine reactivation occurred with maximum efficiency during the early stages of lateral escape, with tectonic transport in the overlying units being sub-perpendicular to it.