EUROPE/Permian to Recent Evolution 117 giving rise to the development of the large Thulean flood basalt province that had, during the Paleocene, a radius of more than 1000 km At the Paleocene– Eocene transition, crustal separation was achieved between Greenland and Europe to the west of the Rockall-Hatton Bank and in the NorwegianGreenland Sea, paving the way for opening of the Arctic-North Atlantic Ocean During the Turonian–Santonian, Africa began to converge with Europe in a counter-clockwise rotational mode Ensuing space constraints within the Tethyan belt were compensated by the activation of new subduction zones and the onset of closure of the Alpine Tethys and the Bay of Biscay Late Cretaceous Late Cretaceous regional thermal subsidence of the North Sea Basin, the Polish Trough, the Paris Basin, and the Tethys shelves, as well as of the Western Shelves, combined with cyclically rising sea-levels, accounted for broad overstepping of the Mid-Cretaceous basin margins This caused a drastic reduction of clastic supply to these basins in which sedimentation became carbonate-dominated from Cenomanian times onward By end-Cretaceous times, much of the WCE was covered by the ‘Chalk’ sea, water depths of which ranged from neritic to bathyal, as evident in the axial parts of the North Sea Basin (Figure 12) However, commencing in Late Turonian times, compressional stresses were exerted on the southern margin of the WCE, causing inversion of Mesozoic tensional basins and upthrusting of basement blocks by reactivation of pre-existing crustal discontinuities (Figure 3) The intra-Senonian pulse of intraplate compression, which affected the Polish Trough, the Fennoscandian Border Zone, the Bohemian Massive, the Sub-Hercynian, Lower Saxony, West Netherlands, and the Sole Pit Basins, as well as the southern parts of the North Sea rift, can be related to compressional stresses which were projected from the AlpineCarpathian orogenic wedge through the oceanic lithosphere of the Alpine Tethys into the lithosphere of WCE From the uplifted basement blocks of the Bohemian Massif and the Polish inversion axis, clastics began to be shed into the surrounding Chalk seas (Figure 12) Paleocene The second, more intense, Paleocene phase of intraplate compression, which affected about the same areas, and to a lesser degree also the Tethys shelves of the Western and Central Alps, the Paris Basin and the Channel area, probably marks the collision of the Alpine-Carpathian orogenic wedge with its East Alpine-Carpathian foreland and with the Brianc¸ onnais Terrane in the West and Central Alpine domain (see Europe: The Alps) The most distal intraplate compressional structures occurred at a distance of some 1500 km to the north-west of the contemporary collision front The Paleocene phase of foreland compression, during which a Rocky Mountain-type array of basement blocks was upthrusted in the Bohemian Massif and the Polish Trough was deeply inverted, involved also broad lithospheric folding, causing a regional regression, the disruption of the Late Cretaceous carbonate platforms, and accelerated subsidence of the North Sea Basin Combined with plume-related thermal doming of the British Isles during the development of the Thulean flood basalt province, sedimentation in the North Sea Basin changed at the end of the Danian from carbonates to clastics At the same time, this basin became isolated from the Tethys and Atlantic seas but remained open to the Norwegian-Greenland Sea (Figure 13) On the other hand, mixed carbonate-clastic environments persisted on the Western Shelves, that were not affected by this pulse of intraplate compression However, Paleocene clastic influx into the Paris Basin from southern sources is probably related to the uplift of the Armorican-Massif Central arch in response to compressional stresses that were exerted on the shelves of Southern France during the early phases of the Pyrenean orogeny that had commenced during the Senonian This is compatible with the PaleoceneEocene development of the Languedoc-Provenc¸ al fold-and-thrust belt of Southern France, that involved inversion of Mesozoic extensional basins Paleocene intrusion of mafic dykes in the Massif Central, Vosges, Black Forest, and the Bohemian Massif, which must be related to partial melting of the lithospheric thermal boundary layer, probably reflected a mantle plume-related increase in the potential temperature of the asthenosphere, resulting in a renewed destabilization of the lithosphere On the other hand, Paleocene compressional inversion of the Polish Trough and upthrusting of basement blocks in the Bohemian Massif apparently caused thickening of the crust (Figure 2) Opening of the Arctic–North Atlantic and Collisional Interaction of the Alpine Orogen with its Foreland With the Early Eocene onset of sea-floor spreading in the Arctic-North Atlantic, volcanic activity ceased on the shelves of the British Isles and the RockallHatton-Faeroe Bank With this, their post-rift thermal subsidence commenced, whilst thermal subsidence