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The Geological Survey of Norway (NGU) has produced new aeromagnetic and gravity maps from Norway and adjacent areas, compiled from ground, airborne and satellite data. Petrophysical measurements on core samples, hand specimens and on in situ bedrock exposures are essential for the interpretation of these maps. Onshore, the most prominent gravity and magnetic anomalies are attributed to lower crustal rocks that have been brought closer to the surface. The asymmetry of the gravity anomalies along the Lapland Granulite Belt and Kongsberg–Bamble Complex, combined with the steep gradient, points to the overthrusted high-density granulites as being the main source of the observed anomalies. The Kongsberg–Bamble anomaly can be traced southwards through the Kattegat to southern Sweden. This concept of gravity field modelling can also be applied to the Mid-Norwegian continental shelf and could partially explain the observed high-density rocks occurring below the Møre and Vøring basins and in the Lofoten area. Extrapolations of Late-Caledonian detachment structures occurring on the mainland can be traced on aeromagnetic and gravimetric images towards the NW across the continental margin. Subcropping Late Palaeozoic to Cenozoic sedimentary units along the mid-Norwegian coast produce a conspicuous magnetic anomaly pattern. The asymmetry of the low-amplitude anomalies, with a steep gradient and a negative anomaly to the east and a gentler gradient to the west, relates the anomalies to gently westward dipping strata. Recent aeromagnetic surveys in the Barents Sea have revealed negative magnetic anomalies associated with shallow salt diapirs. Buried Quaternary channels partly filled with gravel and boulders of crystalline rocks generate magnetic anomalies in the North Sea. The new maps also show that the opening of the Norwegian–Greenland Sea occurred along stable continental margins without offsets across minor fracture zones, or involving jumps in the spreading axis. A triple junction formed at 48 Ma between the Lofoten and Norway Basins.

A series of in situ enrichment experiments was carried out at 1265 m water depth in the Sognefjord on the west coast of Norway in order to follow the short-term fate of freshly settled phytodetritus in a deep-sea sediment. For all experiments, a deep-sea benthic chamber lander system was used. In the lander chambers, a settling spring bloom was simulated by the injection of 0.2 g of freeze-dried Thalassiosira rotula, an equivalent of 1 g organic C m -2 . The algae were 98% 13 C-labeled, thus enabling us to follow the processing of the carbon by bacteria and macrofauna. Experiment duration varied from 8 h to 3 d. The total oxygen consumption of the sediments increased by approximately 25% due to particulate organic matter (POM) enrichment. Macrofauna organisms became immediately labeled with 13 C. After 3 d, 100% of the individuals sampled down to 10 cm sediment depth had taken up 13 C from the phytodetritus added. Bacterial uptake of the tracer was fast too, and even bacteria in deeper sediment layers had incorporated the fresh material within 3 d. Our study documents the rapid downward mixing of labile organic matter and the importance of macrofauna for this process. We present the first evidence for the immediate breakdown and incorporation of POM by bacteria even in deep sediment layers. Surprisingly, the initial processing of carbon was dominated by macrofauna, although the group comprises < 5% of the benthic biomass.Altogether, approximately 5% of the carbon added had been processed within 3 d, with the majority being released from the sediment as CO 2 . Due to the good comparability of our study site with midslope settings at continental margins, in general, we propose that the processes we observed are widespread at continental margins and are significant for the biogeochemical cycling of particulate matter on the slope.

We have acquired and processed new aeromagnetic data that cover the entire oceanic Norway Basin located between the Møre volcanic rifted margin and the Jan Mayen microcontinent (JMMC). The new compilation allows us to revisit the structure of the conjugate volcanic (rifted) margins and the spreading evolution of the Norway Basin from the Early Eocene breakup time to the Late Oligocene when the Aegir Ridge became extinct. The volcanic margins (in a strict sense) that formed before the opening of the Norway Basin have been disconnected with the previous Jurassic-Mid-Cretaceous episode of crustal thinning. We also show evidence of relationships between the margin architecture, the breakup magmatism distribution along the continent-oceanic transition, and the subsequent oceanic segmentation. The Norway Basin shows a complex system of asymmetric oceanic segments locally affected by episodic ridge jumps. The new aeromagnetic compilation also confirms that a fan-shaped spreading evolution of the Norway Basin was clearly active before the cessation of seafloor spreading and extinction of the Aegir Ridge. An important Mid-Eocene kinematic event at around magnetic chron C21r can be recognized in the Norway Basin. This event coincides with the onset of diking and increasing rifting activity (and possible oceanic accretion?) between the proto-JMMC and the East Greenland margin. It led to a second phase of breakup and microcontinent formation in the Norwegian-Greenland Sea~26 Myrs later in the Oligocene.

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