The Evolution of the Galapagos Mantle Plume: From Large Igneous Province to Ocean Island Basalt
| dc.contributor.author | Trela, Jarek | en |
| dc.contributor.committeechair | Gazel, Esteban | en |
| dc.contributor.committeemember | Caddick, Mark J. | en |
| dc.contributor.committeemember | Herzberg, Claude T. | en |
| dc.contributor.committeemember | Zhou, Ying | en |
| dc.contributor.department | Geosciences | en |
| dc.date.accessioned | 2017-04-22T08:00:48Z | en |
| dc.date.available | 2017-04-22T08:00:48Z | en |
| dc.date.issued | 2017-04-21 | en |
| dc.description.abstract | Mantle plumes are anomalously hot, narrow upwellings of mantle material that originate at the core-mantle boundary. As plumes rise they may form volumetrically large "heads" (~1000 km in diameter) with narrower (~100 km) "tails." Plume head melting is thought to form Large Igneous Provinces (LIPs), vast outpourings of basaltic lava (~106 km3), while plume tail melting forms linear chains of ocean island basalts (OIBs) similar the Emperor-Hawaii Seamount chain. Mantle plume derived melts indicate that these structures sample deep Earth geochemical and lithological heterogeneities. Studying plume-derived lavas can clarify important planetary-scale questions relating to the accretion of the Earth, primordial geochemical reservoirs, the fate of subducted materials, planetary differentiation, and convective mixing. | en |
| dc.description.abstractgeneral | Mantle plumes are hot, narrow upwellings of plastically flowing mantle material. These structures are thought to originate at the core-mantle boundary. Because mantle plumes originate in the deep interior of the planet, they are though to sample both primitive materials that are remnants of Earth’s formation as well as recycled crustal materials that have been subducted from the surface into the deep interior of the planet. When mantle plumes near the surface of the planet they begin to partially melt during a process known as adiabatic decompression melting. When these melts cool, they crystallize to form basalts. These rocks and their associated minerals can be studied to determine lava temperatures and pressures of formation. The geologic record suggests that relatively recently mantle plumes cool and eventually become magmatically inactive. In this project, we used the Galapagos plume as a case study to investigate why it has systematically cooled over the last 90 Ma. The Galapagos mantle plume is possibly the oldest active plume and records a 90 Ma volcanic evolution. We studied Galapagos-related lavas and olivine crystals across the entire 90 Ma evolution of the plume to better understand the life-death cycle of mantle plumes. Our data suggest that the plume may be cooling due to an increase in the amount of recycled oceanic crust. Alternatively, a recycled oceanic crust component could have always been present in the source of the plume, though was diluted during high degrees of partial melting when it was hottest at 90 Ma. | en |
| dc.description.degree | Ph. D. | en |
| dc.format.medium | ETD | en |
| dc.identifier.other | vt_gsexam:10029 | en |
| dc.identifier.uri | http://hdl.handle.net/10919/77438 | en |
| dc.publisher | Virginia Tech | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject | Geology | en |
| dc.subject | Geochemistry | en |
| dc.subject | mantle plumes | en |
| dc.subject | olivine | en |
| dc.subject | thermometry | en |
| dc.subject | petrology | en |
| dc.subject | hotspots | en |
| dc.subject | isotopes | en |
| dc.title | The Evolution of the Galapagos Mantle Plume: From Large Igneous Province to Ocean Island Basalt | en |
| dc.type | Dissertation | en |
| thesis.degree.discipline | Geosciences | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | doctoral | en |
| thesis.degree.name | Ph. D. | en |
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