The stratigraphy, environment of eruption and age of the Faroes Lava Group, NE Atlantic Ocean
David Ellis, Brian R. Bell, David W. Jolley, Michelle O’Callaghan, 2002. "The stratigraphy, environment of eruption and age of the Faroes Lava Group, NE Atlantic Ocean", The North Atlantic Igneous Province: Stratigraphy, Tectonic, Volcanic and Magmatic Processes, D. W. Jolley, B. R. Bell
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Palaeogene volcanism on the NW margin of the Faroe-Shetland Basin is represented by the Faroes Lava Group, within an age range of 57.5–60.56 Ma. The volcanic sequence comprises >1000 m of basaltic volcaniclastic rocks deposited in estuarine or marginal lagoons, overlain by three laterally-extensive formations of subaerial facies basaltic lavas: Lower, c. 3250 m; Middle, c. 1400 m; Upper, at least 900 m (top not preserved). The Lower and Upper formations comprise high-volume sheet flows, commonly with ferrallitized tops, interbedded with reddened, thin, fluvial claystone and basaltic siltstone deposits. Laterally-impersistent coals occur within the Lower Lava Formation. The Coal-bearing Formation (c. 20 m) was deposited in an overbank floodplain environment during an hiatus in the volcanism between the Lower and Middle formations. The Volcaniclastic Sandstone Sequence comprises hydroclastic and pyroclastic deposits which post-date the Coal-bearing Formation and represent a return to volcanism, prior to the eruption of the Middle Lava Formation which is mainly characterized by inflated pahoehoe flows. The onshore sequence of the Faroes Lava Group can be correlated with basaltic flows within the Faroe-Shetland Basin, where lavas in Well 205/9-1 are interpreted to be of Lower Lava Formation affinity, possibly erupted from a local vent system. Seismic and gravity mapping and modelling suggest that the offshore extension of the Lower Lava Formation, together with the oldest part of the Middle Lava Formation, comprise subaqueous hyaloclastites deposited in a prograding Gilbert-type lava delta system. The youngest part of the Middle Lava Formation and all of the Upper Lava Formation occur as subaerial facies lavas within the basin.
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The North Atlantic Igneous Province has been the subject of extensive scientific investigation over the past thirty years, with a wide field of knowledge being accumulated. Recently, recognition of the potential role of Large Igneous Provinces in affecting ocean and atmosphere systems and biotic evolutionary pathways has lead to increased interest in this province. This has been further stimulated by the expansion in the search for oil and gas in Mesozoic and Tertiary sediments along the NE Atlantic Margin. An improved understanding of the interaction between igneous and sedimentary processes is vital for the identification of potential hydrocarbon resources.
The regions covered include continental margin Norway, east and west Greenland, the Faroe-Shetland Basin and the Faroe Islands themselves. The papers in this book contain new data and interpretations of North Atlantic Igneous Province magmatic processes, rift evolution, tectonics, stratigraphy (chemostratigraphy, biostratigraphy, seismic and isotope stratigraphy) and sediment dispersal. Many of the papers adopt a multidisciplinary approach to tha analysis and interpretation of complex volcanic and sedimentary sequences. These new data, and the reviews and compilations of existing data provide the reader with access to current research directions in North Atlantic Igneous Province geology.