Faculté des sciences

Metamorphic core complexes and gneiss-cored culminations along the Mid-Norwegian margin: an overview and some current ideas

Osmundsen, Per Terje ; Braathen, Alvar ; Sommaruga, Anna ; Skilbrei, Jan Reidar ; Nordgulen, Øystein ; Roberts, David ; Andersen, Torgeir B. ; Olesen, Odleiv ; Mosar, Jon

In: Norwegian Petroleum Society Special Publications, 2005, vol. 12, p. 29-41

From the Palacozoic to the Cretaceous, crustal thinning in the Mid Norway area was associated with the denudation of gneiss-cored culminations and metamorphic core complexes in the footwalls of major extensional faults. The development of the culminations led to warping and deactivation of early detachments, to the nucleation of new faults in more distal positions and to the exhumation of... Plus

Ajouter à la liste personnelle
    Summary
    From the Palacozoic to the Cretaceous, crustal thinning in the Mid Norway area was associated with the denudation of gneiss-cored culminations and metamorphic core complexes in the footwalls of major extensional faults. The development of the culminations led to warping and deactivation of early detachments, to the nucleation of new faults in more distal positions and to the exhumation of highgrade metamorphic rocks to more shallow levels in the crust. Some of the culminations and core complexes became part of the erosional template in Mid-Late Palaeozoic time, some were probably exhumed in the Mesozoic, whereas some may never have reached the surface. We present an overview of five types of gneiss-cored culminations and core complexes that have been identified in the field, through the interpretation of offshore, long-offset seismic reflection data. We furthermore address their mechanism(s) of formation, and their role in the progressive evolution of the Mid-Norwegian margin.