Cretaceous‐Paleocene Evolution and Crustal Structure of the Northern Vøring Margin (Offshore Mid‐Norway): Results from Integrated Geological and Geophysical Study

Abstract

We present results of a multidisciplinary study of the northern segment of the Vøring volcanic rifted margin, offshore mid‐Norway. This segment represents a transitional margin domain that is less investigated compared to the adjacent segments of the margin. In order to understand the geological evolution of the study area, we performed an integrated interpretation of an extensive geological and geophysical data set. This data set includes recently acquired and reprocessed 2‐D reflection seismic, published refraction data and potential field data, as well as new borehole data. Two‐dimensional potential field modeling was performed to better assess the crustal architecture and evolution of the northern Vøring Margin. We then consider how crustal‐scale structures and processes affected the basin formation. The outer and distal northern Vøring Margin represents a series of deep Cretaceous (Træna Basin and Någrind Syncline) and Cretaceous‐Paleocene (Hel Graben) sag subbasins underlain by a significantly thinned continental crust. These subbasins developed in between structural highs (Utgard, Nyk, and Grimm Highs), which are underlain by a thicker crust and interpreted as a series of rigid continental blocks (“buffers”). In addition to the regional Late Jurassic‐Early Cretaceous rifting events, we found structural evidence of local Neocomian and mid‐Cretaceous extensional reactivation affecting the northern segment of the Vøring Basin. During the mid‐Late Cretaceous‐Paleocene, the extensional axis within the Vøring Basin province migrated sequentially northwestward to the present‐day continent‐ocean “boundary”. We also show fundamental differences between the volcanic rifted mid‐Norwegian Margin and nonvolcanic (Iberian‐type) margins and how preexisting structures events can shape the evolution and architecture of the margin.

Tectonic Controls on Carbon and Serpentinite Storage in Subducted Upper Oceanic Lithosphere for the Past 320 Ma

“…In these cases the lithospheric mantle is tectonically exhumed into the rock column by asymmetric detachment faulting (Tucholke et al, 2008;Carbotte et al, 2016), exposing mantle peridotites and ultramafics to seawater where serpentinization can occur (Cannat et al, 2010; Figure 2A). We begin our analysis at the initiation of seafloor spreading, neglecting transitional crust that is exposed during continental rifting, although this can also be variably serpentinized (e.g., Zastrozhnov et al, 2018). By estimating the proportion of peridotite present, we also estimate the proportion of the magmatic component.…”

Timing of Breakup and Thermal Evolution of a Pre‐Caledonian Neoproterozoic Exhumed Magma‐Rich Rifted Margin

“…Their magma‐rich counterparts, on the other hand, are often lost by subduction due to metamorphic densification. Exposed crustal sections of the magma‐rich end‐member are therefore much less known, and what we do know about their architecture mainly comes from geophysical methods and drill hole data (e.g., Direen & Crawford, ; Gernigon et al, ; Theissen‐Krah et al, ; Zastrozhnov et al, ). In general, these magma‐rich rifted margins show an anomalously thick ocean‐continent transition (~20‐km thickness), commonly referred to as the outer high (Figure ).…”

Breakup volcanism and plate tectonics in the NW Atlantic

“…Sedimentary rock samples). In the NE Atlantic, subsidence was important in the Vøring and Møre basins, offshore mid-Norway, leading to the accumulation of up to 8 km of sediments in local depocentres (Scheck-Wenderoth et al, 2007;Abdelmalak et al, 2017a;Theissen-Krah et al, 2017;Zastrozhnov et al, 2018). This subsidence event was followed by another phase of rifting in the late Cretaceous / early Paleocene recorded in the whole North Atlantic area and ended with regional uplift during the Danian (65-62 Ma; Dam et al, 1998a).…”