Tectonic Analysis of a Viking Graben Border Fault: ABSTRACT

Abstract

The Viking graben is interpreted as an aulacogen on a passive continental margin. Rifting started in the Late Permian and continued periodically throughout the Mesozoic. The main tectonic events occurred in the Late Jurassic and Early Cretaceous, namely the late Kimmerian phases. Toward the end of the Cretaceous, the taphrogeny ceased and the graben became part of a rigid continental margin. The Tertiary basins had their depocenters close to the Viking and the Central graben axes, but the outlines of these smooth and rounded basins were independent of the graben border faults. However, in the central part of the North Sea, a Viking graben border fault was reactivated in the Paleocene/Eocene. This rejuvenation resulted in such features as flower structures and normal faults along the old Cimmerian Viking graben border fault. Tensional features are found along one border fault dog-leg trend, and the compressive features are found along another. This may be explained as a response to strike-slip reactivation of the old fault. These transient movements coincide with the incipient seafloor spreading in the Norwegian-Greenland Sea and may be End_Page 458------------------------------ related to consequent rotation and/or tilting of the Shetland platform. End_of_Article - Last_Page 459------------