Koppers, Anthony A. P., Yamazaki, T, Geldmacher, J., Anderson, Louise, Beier, Christoph, Buchs, David ![]() |
Abstract
Deep-Earth convection can be understood by studying hotspot volcanoes that form where mantle plumes rise up and intersect the lithosphere, the Earth's rigid outer layer. Hotspots characteristically leave age-progressive trails of volcanoes and seamounts on top of oceanic lithosphere, which in turn allow us to decipher the motion of these plates relative to "fixed" deep-mantle plumes, and their (isotope) geochemistry provides insights into the long-term evolution of mantle source regions. However, it is strongly suggested that the Hawaiian mantle plume moved approximately 15 degrees south between 80 and 50 million years ago. This raises a fundamental question about other hotspot systems in the Pacific, whether or not their mantle plumes experienced a similar amount and direction of motion. Integrated Ocean Drilling Program (IODP) Expedition 330 to the Louisville Seamounts showed that the Louisville hotspot in the South Pacific behaved in a different manner, as its mantle plume remained more or less fixed around 48 degrees S latitude during that same time period. Our findings demonstrate that the Pacific hotspots move independently and that their trajectories may be controlled by differences in subduction zone geometry. Additionally, shipboard geochemistry data shows that, in contrast to Hawaiian volcanoes, the construction of the Louisville Seamounts doesn't involve a shield-building phase dominated by tholeiitic lavas, and trace elements confirm the rather homogenous nature of the Louisville mantle source. Both observations set Louisville apart from the Hawaiian-Emperor seamount trail, whereby the latter has been erupting abundant tholeiites (characteristically up to 95% in volume) and which exhibit a large variability in (isotope) geochemistry and their mantle source
Item Type: | Article |
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Date Type: | Publication |
Status: | Published |
Schools: | Earth and Environmental Sciences |
Subjects: | Q Science > QE Geology |
Uncontrolled Keywords: | Solid-earth geophysics; basement; boreholes; Cenozoic; convection; cores; Cretaceous; crust; East Pacific; Expedition 330; hot spots; igneous rocks; Integrated Ocean Drilling Program; IODP Site U1372; IODP Site U1373; IODP Site U1374; IODP Site U1375; IODP Site U1376; IODP Site U1377; Louisville Ridge; mantle; mantle plumes; marine sediments; Mesozoic; ocean floors; oceanic crust; Pacific Ocean; Paleogene; paleolatitude; paleomagnetism; plate tectonics; seamounts; sediments; South Pacific; Southeast Pacific; Tertiary; volcanic rocks; |
Additional Information: | Louise Anderson, Christoph Beier, David M. Buchs, Li-Hui Chen, Benjamin E. Cohen, Fabien Deschamps, Michael J. Dorais, Daniel Ebuna, Sebastian Ehmann, J. Godfrey Fitton, Patrick M. Fulton, Erdenesaikhan Ganbat, Jeffrey S. Gee, Cedric Hamelin, Takeshi Hanyu, Hiroyuki Hoshi, Lara Kalnins, Johnathon Kell, Shiki Machida, John J. Mahoney, Kazuyoshi Moriya, Alexander R.L. Nichols, Nicola Pressling, Svenja Rausch, Shin-ichi Sano, Jason B. Sylvan, and Rebecca Williams were part of the IODP Expedition 330 Scientific Party |
Publisher: | Integrated Ocean Drilling Program Management International |
Related URLs: | |
Last Modified: | 25 Oct 2022 08:06 |
URI: | https://orca.cardiff.ac.uk/id/eprint/51442 |
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