An Analysis of the Geochemical Composition of Volcanic Glasses and the Relationship of Their Proximity to the Mantle Plume Beneath Iceland

• Main Author: Tackett, Cassandra
• Other Authors: Barton, Michael
• Format: Thesis
• Language: English
• Published: The Ohio State University 2023
• Subjects: Iceland; Geochemistry; Petrology; Volcanology; Mantle Plume; Variation Diagrams; Laki; Askja; Bardarbunga; Grimsvotn; Hekla
• Online Access: http://hdl.handle.net/1811/102914

Iceland is a geologically complex country with a multitude of different types of volcanoes, while also sitting atop of a mantle plume. The objective of this paper is to evaluate the chemical compositions of volcanic glass analyses from Askja, Bardarbunga, Fagradalsfjall, Geitafell, Grimsvotn/Laki, Hekla, and Theistareykir in order to determine the effect of being in proximity to the mantle plume beneath Iceland. In the case of Grimsvotn/Laki, the effect of being directly atop the center of the mantle plume. Variation diagrams are of importance in this case because trends between chemical compositions can be recognized. There will be trends that can be expected from basaltic magmas which is why the analyses were plotted against MgO. The methods used in this paper were taking public analyses data from literature, calculating the averages, maximums, minimums, and standard deviations in Microsoft Excel and plotting and creating these variation diagrams in the software CoPlot. The results were conclusive in the fact that the volcanoes Askja, Bardarbunga, Fagradalsfjall, Geitafell, and Grimsvotn/Laki followed the expected trends. In deeper discussion, Grimsvotn/Laki may be affected by the mantle plume because of large MgO variations. Hekla and Theistareykir fell off the expected trends creating some questions about why. Melt inclusions may be at fault for Theistareykir falling off the trends because that is the only data available. To conclude, proximity to the mantle plume may not be the direct cause affecting the volcanoes. Additionally, melt inclusions may not be accurate in addition to glasses in representing chemical composition trends. No embargo Academic Major: Earth Sciences