Document Type

Student Presentation

Presentation Date

4-18-2016

Faculty Sponsor

Dorsey Wanless

Abstract

The Galápagos platform is characterized by a complex magmatic plumbing system attributed to a hot spot mantle plume in addition to the Galápagos spreading center. The resulting topography involves a chain of volcanos that sit on top of a large submarine platform that rises 3.5 km above the surrounding seafloor. Additionally, there are extensive rift zones surrounding the platform. Side-scan sonar maps of the seafloor indicate consolidated bodies of rock (up to 30 km in length) on the western flanks of the Galápagos platform, which are interpreted as individual large lava flows. Two of these lava flows have been sampled using a submarine remotely operated vehicle (ROV) on a Nautilus research cruise (#064) in order to determine how they relate to one another and to the greater Galápagos magmatic system. It is unknown the source for these uncharacteristically long flows because of the variety of magmatism for this region. Potential magmatic sources for these flows are the adjacent subaerial volcano Fernandina or a submarine rift zone, which can be traced radially outward from the Galápagos platform. 25 samples have been collected for geochemical analyses to investigate the origin of these deep marine flows. First, glass has been collected from all 25 samples using a binocular microscope, and has been cleaned twice using a Sonicator. Next, these samples were dissolved in a series of acids for solution ICP-MS analysis, to determine trace element contents of the lavas that comprise the flows. The data from the two flows will be compared to determine if they have the same source. Next the deep water flow compositions will be compared to previously studied remotely operated vehicle (ROV) on a Nautilus research cruise (#064) in order to determine how they relate to one another and to the greater Galápagos magmatic system. It is unknown the source for these uncharacteristically long flows because of the variety of magmatism for this region. Potential magmatic sources for these flows are the adjacent subaerial volcano Fernandina or a submarine rift zone, which can be traced radially outward from the Galápagos platform. 25 samples have been collected for geochemical analyses to investigate the origin of these deep marine flows. First, glass has been collected from all 25 samples using a binocular microscope, and has been cleaned twice using a Sonicator. Next, these samples were dissolved in a series of acids for solution ICP-MS analysis, to determine trace element contents of the lavas that comprise the flows. The data from the two flows will be compared to determine if they have the same source. Next the deep water flow compositions will be compared to previously studied submarine samples [1], and to subaerial samples of Fernandina volcano. Results will have implications for the Galápagos magmatic plumbing system, as it generates these large deep-marine flows.

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