Tectonic control on Jurassic to Early Cretaceous sedimentation in the Dutch Central Graben; an integrated analysis of seismic and well log data

Abstract

One of the best illustrations of the complex interplay between extensional faulting, salt movement and eustasy is the deposition of the Jurassic to Early Cretaceous sediments in the Dutch Central Graben. We have quantified this deposition by a multi-scale tectonic successions approach employing two ENE-WSW seismic sections perpendicular to the strike of the basin. Our structural reconstruction of the interpreted seismic sections can be grouped in three main phases of basin development, starting with initial deposition focused on the basin center during sedimentation of the Schieland Group. This initial period was followed by deposition along the former basin margins in rim-synclines, which was coeval with the formation of well-documented turtle anticlines during sedimentation of the Scruff Group, followed by tectonic inversion. Building over the well-studied stratigraphic framework in the Dutch offshore, we present a higher resolution well-logs and seismic model of the Jurassic - Early Cretaceous which is able to differentiate 6 to 8 tectonic successions during the deposition of the Schieland Group. These tectonic successions demonstrate a laterally variable alternation of tectonic activity and quiescence controlling sedimentation. This interpretation contrasts with the analysis of the marginal Scruff Group, where results show that 3rd order sea-level fluctuations are the major control on observed sedimentary cyclicity expressed in well log and lithological data. Furthermore, the lateral variability of tectonic successions between the studied transects highlights the importance of local variability in deposition and facies distribution during syn-rift sedimentation in space and over time.