Author:

Keywords:

Science & Technology, Physical Sciences, Geology, Geosciences, Multidisciplinary, North Atlantic Igneous Province, volcanic rifted margins, LIP formation, mantle plume versus alternatives, continent breakup, VOLCANIC CONTINENTAL MARGINS, HIGH HE-3/HE-4 RATIOS, DISKO WEST GREENLAND, HIGH-MGO LIQUIDS, V-SHAPED RIDGES, K-AR AGES, CRUSTAL STRUCTURE, MANTLE PLUME, ICELAND PLUME, MELT GENERATION, Geochemistry & Geophysics

Abstract:

The mantle plume concept is currently being challenged as an explanation for North Atlantic Igneous Province formation. Alternative models have been suggested, including delamination, meteorite impact, small-scale rift-related convection, and chemical mantle heterogeneities. We review available data sets on uplift, strain localization, age and chemistry of igneous material, and tomography for the North Atlantic Igneous Province and compare them with predictions from the mantle plume and alternative models. The mantle plume concept is quite successful in explaining the formation of the North Atlantic Igneous Province, but unexplained aspects remain Delamination and impact models are currently not supported. Rift-related small-scale convection models appear to be able to explain volcanic rifted margin volcanism well.However, the most important problem that nonplume models need to overcome is the continuing, long-lived melt anomaly extending via the Greenland and Faeroe ridges to Iceland. Mantle heterogeneities resulting from an ancient subducted slab are included in plate tectonic models to explain the continuing melt production as an alternative to the mantle plume model, but there are still uncertainties related to this idea that need to be solved.© 2007 The Geological Society of America.