Viscosity of fayalite melt at high pressure and the evolution of the Iceland mantle plume
Part 1 The viscosity of silicate melts is a fundamental physical property that determines the mobility and transport behaviour of magma on the surface and in planetary interiors. The viscosity of liquid fayalite (Fe2SiO4), the Fe-rich end-member of the abundant upper mantle mineral olivine, was dete...
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ftunivedinburgh:oai:era.ed.ac.uk:1842/20971 2023-07-30T04:03:56+02:00 Viscosity of fayalite melt at high pressure and the evolution of the Iceland mantle plume Spice, Holly Elizabeth Cockell, Charles Fitton, Godfrey Kirstein, Linda Engineering and Physical Sciences Research Council (EPSRC) 27/06/2016 application/pdf http://hdl.handle.net/1842/20971 en eng The University of Edinburgh The University of Edinburgh. College of Science and Engineering Spice, H., Sanloup, C., Cochain, B., de Grouchy, C., Kono, Y., 2015. Viscosity of liquid fayalite up to 9 GPa. Geochimica et Cosmochimica Acta 148, 219-227. http://hdl.handle.net/1842/20971 Attribution-NonCommercial-ShareAlike 4.0 International http://creativecommons.org/licenses/by-nc-sa/4.0/ melt viscosity high pressure mantle plume temperature Thesis or Dissertation Doctoral PhD Doctor of Philosophy 2016 ftunivedinburgh 2023-07-09T20:29:23Z Part 1 The viscosity of silicate melts is a fundamental physical property that determines the mobility and transport behaviour of magma on the surface and in planetary interiors. The viscosity of liquid fayalite (Fe2SiO4), the Fe-rich end-member of the abundant upper mantle mineral olivine, was determined up to 9.2 GPa and 1850 °C using in situ falling sphere viscometry and X-ray radiography imaging. The viscosity of liquid fayalite was found to decrease with pressure both along the melting curve and an isotherm, with temperature having very little influence on viscosity at high pressure. This work is the first to determine the viscosity of a highly depolymerized silicate melt at high pressure as only recent advances in experimental techniques have allowed the difficulties associated with studying depolymerized liquids at high pressure to be overcome. The results are in contrast with previous studies on moderately depolymerized silicate melts such as diopside and peridotite which found viscosity to initially increase with pressure. In accordance with recent in situ structural measurements on liquid fayalite, the viscosity decrease is likely a result of the increase in Fe-O coordination with pressure. The results show that the behaviour of silicate melts at depth is strongly dependent on the melt structure and composition. Part 2 The magnitude of the thermal anomaly at hotspot locations has a fundamental influence on the dynamics of mantle melting and therefore has an important role in shaping the surface of our planet. The North Atlantic Igneous Province (NAIP) is the surface expression of a major mantle plume and is unique in the fact that it has a complete magmatic history. The highest 3He/4He volcanic rocks on Earth are found in the early NAIP picrites of West Greenland and Bafin Island and high 3He/4He rocks are still erupted on Iceland today. However, the relationship between 3He/4He and mantle plumes has remained enigmatic. The main aim of this work is to use the ideal opportunity provided by the NAIP to ... Doctoral or Postdoctoral Thesis Greenland Iceland North Atlantic Edinburgh Research Archive (ERA - University of Edinburgh) Greenland |
institution |
Open Polar |
collection |
Edinburgh Research Archive (ERA - University of Edinburgh) |
op_collection_id |
ftunivedinburgh |
language |
English |
topic |
melt viscosity high pressure mantle plume temperature |
spellingShingle |
melt viscosity high pressure mantle plume temperature Spice, Holly Elizabeth Viscosity of fayalite melt at high pressure and the evolution of the Iceland mantle plume |
topic_facet |
melt viscosity high pressure mantle plume temperature |
description |
Part 1 The viscosity of silicate melts is a fundamental physical property that determines the mobility and transport behaviour of magma on the surface and in planetary interiors. The viscosity of liquid fayalite (Fe2SiO4), the Fe-rich end-member of the abundant upper mantle mineral olivine, was determined up to 9.2 GPa and 1850 °C using in situ falling sphere viscometry and X-ray radiography imaging. The viscosity of liquid fayalite was found to decrease with pressure both along the melting curve and an isotherm, with temperature having very little influence on viscosity at high pressure. This work is the first to determine the viscosity of a highly depolymerized silicate melt at high pressure as only recent advances in experimental techniques have allowed the difficulties associated with studying depolymerized liquids at high pressure to be overcome. The results are in contrast with previous studies on moderately depolymerized silicate melts such as diopside and peridotite which found viscosity to initially increase with pressure. In accordance with recent in situ structural measurements on liquid fayalite, the viscosity decrease is likely a result of the increase in Fe-O coordination with pressure. The results show that the behaviour of silicate melts at depth is strongly dependent on the melt structure and composition. Part 2 The magnitude of the thermal anomaly at hotspot locations has a fundamental influence on the dynamics of mantle melting and therefore has an important role in shaping the surface of our planet. The North Atlantic Igneous Province (NAIP) is the surface expression of a major mantle plume and is unique in the fact that it has a complete magmatic history. The highest 3He/4He volcanic rocks on Earth are found in the early NAIP picrites of West Greenland and Bafin Island and high 3He/4He rocks are still erupted on Iceland today. However, the relationship between 3He/4He and mantle plumes has remained enigmatic. The main aim of this work is to use the ideal opportunity provided by the NAIP to ... |
author2 |
Cockell, Charles Fitton, Godfrey Kirstein, Linda Engineering and Physical Sciences Research Council (EPSRC) |
format |
Doctoral or Postdoctoral Thesis |
author |
Spice, Holly Elizabeth |
author_facet |
Spice, Holly Elizabeth |
author_sort |
Spice, Holly Elizabeth |
title |
Viscosity of fayalite melt at high pressure and the evolution of the Iceland mantle plume |
title_short |
Viscosity of fayalite melt at high pressure and the evolution of the Iceland mantle plume |
title_full |
Viscosity of fayalite melt at high pressure and the evolution of the Iceland mantle plume |
title_fullStr |
Viscosity of fayalite melt at high pressure and the evolution of the Iceland mantle plume |
title_full_unstemmed |
Viscosity of fayalite melt at high pressure and the evolution of the Iceland mantle plume |
title_sort |
viscosity of fayalite melt at high pressure and the evolution of the iceland mantle plume |
publisher |
The University of Edinburgh |
publishDate |
2016 |
url |
http://hdl.handle.net/1842/20971 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Iceland North Atlantic |
genre_facet |
Greenland Iceland North Atlantic |
op_relation |
The University of Edinburgh. College of Science and Engineering Spice, H., Sanloup, C., Cochain, B., de Grouchy, C., Kono, Y., 2015. Viscosity of liquid fayalite up to 9 GPa. Geochimica et Cosmochimica Acta 148, 219-227. http://hdl.handle.net/1842/20971 |
op_rights |
Attribution-NonCommercial-ShareAlike 4.0 International http://creativecommons.org/licenses/by-nc-sa/4.0/ |
_version_ |
1772815075023781888 |