Integrated Ocean Drilling Program Expedition 330 preliminary report; Louisville Seamount trail; implications for geodynamic mantle flow models and the geochemical evolution of primary hotspots; 13 December 2010-11 February 2011

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doi: 10.2204/iodp.pr.330.2011
Author(s): Koppers, Anthony A. P.; Yamazaki, Toshitsugu; Geldmacher, Jörg; Anderson, Louise; Beier, Christoph; Buchs, David M.; Chen Lihui; Cohen, Benjamin E.; Deschamps, Fabien; Dorais, Michael J.; Ebuna, Daniel R.; Fitton, J. Godfrey; Fulton, Patrick M.; Ganbat, Erdenesaikhan; Gee, Jeffrey S.; Hamelin, Cedric; Hanyu, Takeshi; Hoshi, Hiroyuki; Kalnins, Lara; Kell, Johnathon; Machida, Shiki; Mahoney, John J.; Moriya, Kazuyoshi; Nichols, Alexander R. I.; Pressling, Nicola J.; Rausch, Svenja; Sano, Shin-ichi; Sylvan, Jason B.; Williams, Rebecca
Integrated Ocean Drilling Program, Expedition 330 Scientists, College Station, TX
Author Affiliation(s): Primary:
Oregon State University, College of Oceanic and Atmospheric Sciences, Corvallis, OR, United States
Other:
Geological Survey of Japan, Japan
Integrated Ocean Drilling Program, United States
University of Leicester, United Kingdom
University of Erlangen-Nürnberg, Germany
Australian National University, Australia
Nanjing University, China
University of Queensland, Australia
Université de Montpellier II, France
Brigham Young University, United States
Scripps Institution of Oceanography, United States
University of Edinburgh, United Kingdom
University of Texas at Austin, United States
Tohoku University, Japan
Institut de Physique du Globe de Paris, France
Japan Agency for Marine-Earth Science and Technology, Japan
Aichi University of Education, Japan
University of Oxford, United Kingdom
University of Nebraska-Lincoln, United States
Waseda University, Japan
University of Hawaii at Manoa, United States
University of Southampton, United Kingdom
University of Bremen, Germany
Fukui Prefectural Dinosaur Museum, Japan
University of Southern California-Los Angeles, United States
Source: Preliminary Report (Integrated Ocean Drilling Program), Vol.330, 174p. Publisher: IODP Management International, College Station, TX, United States. ISSN: 1932-9423
Note: In English. 143 refs.
Summary: The Louisville Seamount Trail is a 4300 km long volcanic chain that has been built in the past 80 m.y. as the Pacific plate moved over a persistent mantle melting anomaly or hotspot. Because of its linear morphology and its long-lived age-progressive volcanism, Louisville is the South Pacific counterpart of the much better studied Hawaiian-Emperor Seamount Trail. Together, Louisville and Hawaii are textbook examples of two primary hotspots that have been keystones in deciphering the motion of the Pacific plate relative to a set of "fixed" deep-mantle plumes. However, drilling during Ocean Drilling Program (ODP) Leg 197 in the Emperor Seamounts documented a large ∼15° southward motion of the Hawaiian hotspot prior to 50 Ma. Is it possible that the Hawaiian and Louisville hotspots moved in concert and thus constitute a moving reference frame for modeling plate motion in the Pacific? Alternatively, could they have moved independently, as predicted by mantle flow models that reproduce the observed latitudinal motion for Hawaii but that predict a largely longitudinal shift for the Louisville hotspot? These two end-member geodynamic models were tested during Integrated Ocean Drilling Program (IODP) Expedition 330 to the Louisville Seamount Trail. In addition, existing data from dredged lavas suggest that the mantle plume source of the Louisville hotspot has been remarkably homogeneous for as long as 80 m.y. These lavas are predominantly alkali basalts and likely represent a mostly alkalic shield-building stage, which is in sharp contrast to the massive tholeiitic shield-building stage of Hawaiian volcanoes. Geochemical and isotopic data for the recovered lavas during Expedition 330 will provide insights into the magmatic evolution and melting processes of individual Louisville volcanoes, their progression from shield-building to postshield and (maybe) posterosional stages, the temperature and depth of partial melting of their mantle plume source, and the enigmatic long-lived and apparent geochemical homogeneity of the Louisville mantle source. Collectively, this will enable us to characterize the Louisville Seamount Trail as a product of one of the few global primary hotspots, to better constrain its plume-lithosphere interactions, and to further test the hypothesis that the Ontong Java Plateau formed from the plume head of the Louisville mantle plume around 120 Ma. During Expedition 330 we replicated the drilling strategy of Leg 197, the first expedition to provide compelling evidence for the motion of the Hawaiian mantle plume between 80 and 50 Ma. For that reason we targeted Louisville seamounts that have ages similar to Detroit, Suiko, Nintoku, and Koko Seamounts in the Emperor Seamount Trail. In total, five seamounts were drilled in the Louisville Seamount Trail: Canopus, Rigil, Burton, Achernar, and Hadar Guyots (old to young). By analyzing a large number of time-independent in situ lava flows (and other volcanic eruptive products) from these seamounts using modern paleomagnetic, 40Ar/39Ar geochronological, and geochemical techniques, we will be able to directly compare the paleolatitude estimates and geochemical signatures between the two longest-lived hotspot systems in the Pacific Ocean. We drilled into the summits of the five Louisville guyots and reached volcanic basement at four of these drilling targets....
Year of Publication: 2011
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 18 Geophysics, Solid-Earth; Algae; Alteration; Basalts; Basement; Biostratigraphy; Boreholes; Cenozoic; Chemostratigraphy; Cores; Cretaceous; Crust; Deep drilling; Drilling; East Pacific; Expedition 330; Foraminifera; Geochemistry; Hot spots; IODP Site U1372; IODP Site U1373; IODP Site U1374; IODP Site U1375; IODP Site U1376; IODP Site U1377; Igneous rocks; Integrated Ocean Drilling Program; Invertebrata; Lithostratigraphy; Louisville Seamounts; Magnetostratigraphy; Major elements; Mantle; Mantle plumes; Marine drilling; Mesozoic; Microfossils; Nannofossils; Ocean floors; Oceanic crust; Pacific Ocean; Paleolatitude; Paleomagnetism; Petrology; Phenocrysts; Physical properties; Plantae; Plate tectonics; Protista; Seamounts; Sedimentary rocks; South Pacific; Southeast Pacific; Structural analysis; Trace elements; Volcanic rocks; Well logs
Coordinates: S262936 S262936 W1744345 W1744345
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S283545 S283545 W1732250 W1732250
S334154 S334154 W1712656 W1712656
S321302 S321302 W1715259 W1715250
S381115 S381115 W1683816 W1683816
Record ID: 2011042679
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