2005 Salt Lake City Annual Meeting (October 16–19, 2005)

Paper No. 14
Presentation Time: 5:00 PM

THE ROLE OF FAULT REACTIVATION AND GROWTH IN THE UPLIFT OF WESTERN FENNOSCANDIA ~ THE 'GHOST' OF THE MESOZOIC


REDFIELD, T.F.1, OSMUNDSEN, P.T.2 and HENDRIKS, B.W.H.2, (1)Geodynamics, Royal Geological Survey of the Kingdom of Norway, Leiv Eirikssons vei 39, Trondheim, 7491, Norway, (2)Crustal Processes, Royal Geological Survey of the Kingdom of Norway, Leiv Eirikssons vei 39, Trondheim, N-7491, Norway, tim.redfield@ngu.no

New structural data, published AFT data, and topographic data suggest that the latest Cretaceous– Cenozoic uplift of western Norway was associated with normal reactivation of the Møre–Trøndelag Fault Complex. Reactivation focused along the base of today's topographic rise, with maximum displacements of the order of 2–3 km. Structural and AFT data indicate that reactivation occurred along a displacement gradient with least normal displacement in the NE and increasing displacements towards the SW. Reactivation commenced in connection with the Triassic to earliest Cretaceous phases of rifting on the Norwegian margin, and probably continued through most of the Tertiary. The Late Cretaceous to Cenozoic topographic development of the Scandes Mountains followed structurally induced templates, such as those described from other areas of active normal faulting. A fault model for the Cenozoic uplift of the Norwegian mainland provides a framework for provenance, erosion and transport of sediments eventually deposited in the offshore post-rift basins in the Latest Cretaceous, Palaeogene and Neogene. The asymmetric topographic profile of Fennoscandia is reflected in the AFT data and suggests that lithospheric flexure places a first-order control on the shape of the Scandes Mountains and the central Fennoscandian craton.