Kinematics of the Eastern Nordvarg Dome, the Barents Sea, Norway: A Hinge Migration Detachment Fold

Enrique F. Novoa, Torbjørn Dahlgren, and Geir Elvebakk
The Barents Sea Exploration Group, Statoil Nord-Norge, Harstad, Norway

The Eastern Nordvarg dome is located in the Bjarmeland Platform, the Barents Sea. It can be described as a doubly plunging symmetric low amplitude anticline which strikes East-West. The core of the dome is inferred to be composed of salt deposited in a Carboniferous-Permian half graben present underneath the anticline. Salt has moved by ductile flow into the core of the fold along a detachment surface. 3D and 2D restorations of the anticline indicated that it grew from Early Triassic to Early Cretaceous. The structure continued growing afterwards but the Late Cretaceous - Tertiary strata are eroded in the study area due to the Cenozoic uplift of the Barents Sea thus removing the evidence. Moreover the preserved Late Permian to Early Cretaceous growth strata and kinematic models indicate that this dome may have grown by hinge migration. However, most detachment folds reported in the literature have been described as growing mainly by progressive limb rotation making the Eastern Nordvarg Dome a rare example of a hinge migration detachment fold. Finally, hinge migration rate calculations indicate that the anticline grew faster after the formation of the Base of Cretaceous Unconformity.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece