120 EUROPE/Permian to Recent Evolution of the North Sea Basin and the Western Shelves continued During the Late Eocene and Oligocene, reorganization of sea-floor spreading axes in the Norwegian-Greenland Sea, the shelves of the British Isles were destabilized by minor wrench faulting in the prolongation of the Iceland ridge and the Charlie Gibbs fracture zones, causing the subsidence of small transtensional basins in the Irish Sea area (Figure 14) Moreover, repeated pulses of basin inversion interfered with the thermal subsidence of the Celtic Sea, Western Approaches, and Channel basins (Figure 3) During the Eocene, thrust-loaded flexural subsidence of the foreland of the Western, Central, and Eastern Alps, and also the Carpathian foreland, commenced Oligocene to Miocene emplacement of the East-Alpine and Carpathian nappe systems was, however, not accompanied by further intraplate compressional deformation of their forelands, thus reflecting mechanical decoupling of these orogens from their forelands By contrast, Late Eocene–Early Oligocene and Late Oligocene–Early Miocene inversion pulses evident in the Celtic Sea, Western Approaches, Channel, Weald, Sole Pit, Broad Fourteens, and West Netherlands basins testify to intermittent and increasing mechanical coupling of the evolving West and Central Alpine Orogen with its foreland (Figures and 14) Crustal shortening in the Western and Central Alps persisted during the Late Miocene and Pliocene, as evident by folding of the Jura Mountains, and may indeed still be going on, as indicated by earthquake activity and geodetic data In the Alpine foreland, development of the tectonically still active European Cainozoic rift system (ECRIS) commenced during the Late Eocene Today this rift system extends over a distance of more than 1000 km from the Dutch North Sea coast to the Mediterranean Its southern elements are the northerlystriking Limagne and the Valence and Bresse grabens, which are superimposed on and flank the Massif Central, respectively These grabens are linked via the Burgundy transfer zone to the northerly-striking Upper Rhine Graben which bifurcates northwards into the north-west-trending Roer Graben and the north-easterly trending Hessian grabens that transect the Rhenish Massif The north-east-striking Eger Graben, which transects the Bohemian Massif, forms an integral part of the ECRIS (Figure 14) Localization of ECRIS involved the reactivation of Permo-Carboniferous shear systems Although characterized by relatively low crustal stretching factors, the evolution of the ECRIS was accompanied by the development of major volcanic centres on the Massif Central, the Rhenish Massif and the Bohemian Massif, particularly during Miocene and Plio-Pleistocene times Seismic tomography indicates that mantle plumes well up beneath the Massif Central and the Rhenish Massif but not beneath the Vosges-Black Forest arch; similar data are, however, not available for the Bohemian Massif Despite this, the evolution of the ECRIS is considered to be a clear case of passive rifting During the Late Eocene, the Valence, Limagne, Bresse, Upper Rhine, and Hessian grabens began to subside in response to northerly-directed compressional stresses that can be related to the collisional interaction of the Pyrenees and the Alps with their forelands These originally-separated rifted basins coalesced during their Oligocene main extensional phase, and the Roer and Eger Grabens started During the Late Oligocene, rifting propagated southward across the Pyrenean Orogen into the Gulf of Lions and along coastal Spain in response to backarc extension, that was controlled by eastward rollback of the subducted Betic-Balearic slab By Late Burdigalian times, crustal separation was achieved, the oceanic Provenc¸ al Basin began to open, and the grabens of southern France became inactive By contrast, the intra-continental parts of the ECRIS remained tectonically active until the present, although their subsidence has been repeatedly interrupted, possibly in conjunction with stresses controlling far-field inversion tectonics By endOligocene times, magmatic activity increased on the Rhenish Shield At the same time, the area of the triple junction between the Upper Rhine, Roer, and Hessian grabens became uplifted, presumably in response to thermal thinning of the lithosphere, interrupting the Oligocene sea-way which had linked the North Sea Basin with the Alpine foreland basin By Middle–Late Miocene times, the Massif Central, the Vosges-Black Forest arch, and slightly later, also the Bohemian Massif, were uplifted This was accompanied by increased mantle-derived volcanic activity At the level of the Moho, a broad anticlinal feature extends from the Massif Central via the Burgundy Transfer zone, the Vosges-Black Forest into the Bohemian Massif (Figure 2) Uplift of these arches probably involved folding of the lithosphere in response to increased collisional coupling of the Alpine Orogen with its foreland Uplift of the Burgundy transfer zone entailed partial erosional isolation of the Paris Basin Under the present north-west-directed stress regime, which had developed during the Miocene and intensified during the Pliocene and reflects a combination of Alpine collisional and Arctic-North Atlantic ridge-push forces, the Upper Rhine Graben is subjected to sinistral shear, the Roer Graben is under active extension, whilst thermal uplift of the Rhenish triple junction continues Moreover, the late phase of accelerated subsidence of the North Sea Basin, commencing in the Pliocene, as well as the