Numerical Modeling of Cenozoic Basin Inversion of the Western Barents Shelf

Numerical models for tectonic inversion and reactivation of pre-existing faults induced by Eocene‒Miocene tectonic stress fields in the Barents Sea are presented. Our goal is to reconstruct stress evolution and to investigate the recorded tectonic inversion events in the western Barents Sea during Eocene and Miocene. We used a finite-element numerical code, ANSYS™ 2013 [2], to simulate stress and fault slip patterns based on two 2D thin plate model setups. Following previous works, we assumed two subsequent major regional inversion events: dextral mega shear plate margin in Early Eocene (Model 1) followed by NW‒SE Atlantic ridge push starting in Miocene (Model 2). The results obtained in Model 1 suggest that the interior of the western Barents Sea was not severely influenced by Early Eocene North Atlantic opening/shearing. The results suggest that Early Eocene sea floor spreading caused stress partitioning along the Senja Fracture Zone. The observed inversion structures may be related to local effects. The results of Model 2 appear to be in agreement with the observed NW–SE contraction, expressed as folds and reverse faults in the study area (e.g. Ringvassøy–Loppa, Bjørnøyrenna, Leirdjupet and Asterias fault complexes). Results of two models suggest presence of compressive structures along the major fault complexes of the western Barents Sea during Miocene but do not favor the development of inversion structure during Eocene.