No abstract

Six wells were drilled in the extensional

This paper presents a model of facies distribution within a set of early Cretaceous, deep‐lacustrine, partially confined turbidite fans (Sea Lion Fan, Sea Lion North Fan and Otter Fan) in the North Falkland Basin, South Atlantic. As a whole, ancient deep‐lacustrine turbidite systems are under‐represented in the literature when compared with those documented in marine basins. Lacustrine turbidite systems can form extensive, good quality hydrocarbon reservoirs, making the understanding of such systems crucial to exploration within lacustrine basins. An integrated analysis of seismic cross‐sections, seismic amplitude extraction maps and 455 m of core has enabled the identification of a series of turbidite fans. The deposits of these fans have been separated into lobe axis, lobe fringe and lobe distal fringe settings. Seismic architectures, observed in the seismic amplitude extraction maps, are interpreted to represent geologically associated heterogeneities, including: feeder systems, terminal mouth lobes, flow deflection, sinuous lobe axis deposits, flow constriction and stranded lobe fringe areas. When found in combination, these architectures suggest ‘partial confinement’ of a system, something that appears to be a key feature in the lacustrine turbidite setting of the North Falkland Basin. Partial confinement of a system occurs when depositionally generated topography controls the flow‐pathway and deposition of subsequent turbidite fan deposits. The term ‘partial confinement’ provides an expression for categorising a system whose depositional boundaries are unconfined by the margins of the basin, yet exhibit evidence of internal confinement, primarily controlled by depositional topography. Understanding the controls that dictate partial confinement; and the resultant distribution of sand‐prone facies within deep‐lacustrine turbidite fans, is important, particularly considering their recent rise as hydrocarbon reservoirs in rift and failed‐rift settings.

No abstract

The Iceland Plume, activated perhaps as early as Late Cretaceous time and extending through the Tertiary, was responsible for the generation of large volumes of igneous rocks, covering an area of roughly 2000 km in diameter, encompassing Greenland, the Voring Basin, the Faeroes, the FaeroeShetland Basin, the Rockall Trough and NW Scotland. Within this large area, magmatism is mainly manifested as lava fields, sediment-sill complexes, and central or strato/shield type volcano complexes.Towards the continental margin of NW Europe, extrusive rocks occur in two distinct geographical areas. SW of the Munkagrunnur Ridge of the Faeroe Platform, lavas are mainly extruded radially from strato /shield volcano complexes. To the NE, in contrast, seismic evidence suggests that the upper part of the Faeroe Plateau Lava Group extrusives originate from the same source that formed the Seaward Dipping Reflector Sequences NW of the Faeroes. Towards the SE of the Faeroes, the distribution of the Faeroe Plateau Lava Group (Upper, Middle and Lower Series) lavas is controlled by pre-existing structure and sea-level fluctuations. Seismic and well evidence confirms that, generally, the Upper Series extends furthest into the Faeroe-Shetland Basin while basaltic progradational units form the SE limit of the Lower Series. Similar structures of possibly the same age have been identified within the NE Rockall Trough.There appear to have been two major phases or pulses of Early Tertiary magmatism within the North Atlantic Igneous Province; an initial outburst at around 62 Ma and a later phase at around 55 Ma.