Geochemical and petrographic analyses of basaltic rocks were performed from five volcanoes on the Big Island of Hawaii. From north to south these volcanoes include: Kohala; Hualalai; Mauna Kea; Mauna Loa; and Kilauea. These volcanoes have formed through several distinct stages of volcanic growth and development. During each of these stages, the lavas extruded will be composed of a distinctive geochemical signature which corresponds to each of the 4 main phases of development. These include a 1) pre-shield building; 2) main shield building; 3) post-shield building; and 4) a rejuvenated stage.
The geochemical results are used to establish the evolutionary stage each volcano is in and provide insight on the sources of the magma driving these eruptions. Over 50 samples were collected from a variety of prehistoric and historic lava flows on Hawaii and prepared in the Department of Geological Sciences. These samples were analyzed for major oxides and trace elements using X-ray fluorescence (XRF) techniques. In addition, a detailed petrographic analysis of thin sections was performed on each of the samples, allowing the mineralogy and textures of these lava flows to be identified. Petrographic results were combined with geochemical results to develop a model for the source of the magma and how it has changed over time. The goal of this project is to investigate the changes in geochemical signature with respect to time and position related to the mantle plume beneath the island of Hawaii and determine the eruptive stage of the volcano based on the geochemistry of the different basalts. The intent was to discover the current stage of development for each of the volcanoes.
Michael A. Krol (Thesis Director)
Christine M. Brandon
Richard L. Enright
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Original document was submitted as an Honors Program requirement. Copyright is held by the author.
Burrell, Autumn A.. (2017). Geochemical and Petrographic Analysis of Basaltic Rocks of the Hawaiian Island: Implications for their Evolutionary Stage of Development. In BSU Honors Program Theses and Projects. Item 205. Available at: https://vc.bridgew.edu/honors_proj/205
Copyright © 2017 Autumn A. Burrell