Influence of tectonism on the composition of acid and basaltic lava

• Main Author: Sigmarsson, Olgeir
• Other Authors: Laboratoire Magmas et Volcans (LMV), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Institute of Earth Sciences, University of Iceland Reykjavik
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2010
• Subjects: [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDE.MCG]Environmental Sciences/Global Changes; Iceland
• Online Access: https://hal.univ-brest.fr/hal-00482056; https://hal.univ-brest.fr/hal-00482056/document; https://hal.univ-brest.fr/hal-00482056/file/Sigmarsson_resume.pdf

The Neovolcanic zones in Iceland are of threefold origin: the Mid-Atlantic rift-zone, the Snæfellsnes “leaky-transform fault”, and South-Iceland transgressive volcanic zone or propagating rift segment. Basalt compositions range from alkali basalts through transitional basalts to tholeiites along the off-rift zones towards the centre of Iceland. Diminishing proportion of garnet-pyroxenite melts towards the centre of the mantle plume is the preferred explanation. The origin of silicic magmas reflects their tectonic settings and appears to be controlled by the crustal geothermal gradient.