[S-CG64] Crust-mantle connections

convener:Yoshihiko Tamura(Research Institute for Marine Geodynamics, Japan Agency for Maine-Earth Science and Technology), Osamu Ishizuka(Geological Survey of Japan, AIST)

The western portion of the Pacific Plate, the oldest oceanic plate in the world, has been drilled several times and, based on Ocean Drilling Program (ODP) Site 801, an understanding of its layers, from pelagic clay through chert to alkali basalts and tholeiitic mid-ocean ridge basalts (MORB), has been established. This oldest oceanic plate is experiencing a renaissance and we propose a strategy to drill the most suitable three sites to recover specific parts of the plate to continue its renaissance. This submitted IODP preproposal is entitled The Renaissance of the Oldest Oceanic Plate: REY (Rare Earth elements and Yttrium) rich Mud, Radiolarite of Jurassic-Cretaceous Boundary (JKB), and Jurassic Oceanic Crust without Moho. The drilling sites, MM, MAT, and MINA, target (1) the most complete sedimentary sequence of pelagic clay including REY-rich mud, (2) newly found outcrops of the Jurassic-Cretaceous boundary (JKB), and (3) MORB tholeiites without Moho, respectively. This session invite scientists who are interested in these exciting drillings.
It is common knowledge that the Moho is the boundary between the crust and the Earths mantle, discovered by and named after the Croatian seismologist Andrija Mohorovicic. The oceanic Moho is defined by seismic reflection images, but seismic profiles generally show that Moho reflections are not universal. Where the Moho can be detected clearly the crust is thicker. A good example is the profile from Kaneda et al. (2010) near Minami-Tori Shima, which is the main motivation for drilling at Site MINA. The session also seeks to explore the crust-mantle connections among ophiolites, at divergent and convergent plate boundaries and ocean island settings based on petrology, geochemistry, geophysics, geochronology, and geodynamics studies.

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[SCG64-01] Synmagmatic faulting partly controls fluid-melt-peridotite reaction and lithospheric melts generation at the crust-mantle transition

*Mathieu Rospabe¹, Mathieu Benoit², Georges Ceuleneer², Mary-Alix Kaczmarek² (1.Research Institute for Marine Geodynamics (IMG), Japan Agency for Marine-Earth Science and Technology, 2.Géosciences Environnement Toulouse (GET), Observatoire Midi-Pyrénées, Université de Toulouse, CNRS, IRD)

[SCG64-02] Multi-stage metasomatism and metamorphism of the Mesoarchean Ulamertoq ultramafic rocks in southern West Greenland

*Ikuya Nishio¹, Tomoaki Morishita¹, Akihiro Tamura¹, Juan Miguel Ramirez Guotana¹, Kenichiro Tani², Yumiko Harigane³, Kristoffer Szilas⁴, D. Graham Pearson⁵ (1.Kanazawa University, 2.Department of Geology and Paleontology, National Museum of Nature and Science, 3.Institute of Geology and Geoinformation Geological Survey of Japan/AIST, 4.University of Copenhagen, 5.University of Alberta)

[SCG64-03] Arc magma genesis: evidence from Kibblewhite Volcanic Complex in the Kermadec arc, New Zealand

★Invited Papers

*Yasuhiro Hirai^1,2, Yoshihiko Tamura², Kaj Hoernle³, Reinhard Werner³, Folkmar Hauff³, Christian Timm⁴, Bogdan Vaglarov², Qing Chang², Takashi Miyazaki², Jun-Ichi Kimura², Takeshi Hanyu² (1.Graduate School of Natural Science and Technology, Kanazawa University, Japan, 2.Research Institute for Marine Geodynamics (IMG), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan, 3.GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany, 4.GNS Science, Lower Hutt, New Zealand)

[SCG64-04] The Atlantis Bank Batholith, SW Indian Ridge, the Link Between Lower Crustal Accretion at High and Low Melt Supply

*Henry J Dick¹ (1.Woods Hole Oceanographic Institution)

[SCG64-05] Oceanic lower crust and uppermost mantle of the Shikoku Basin: insights from expeditions to Mado Megamullion

*Yasuhiko Ohara^1,2,3, Kyoko Okino⁴, Norikatsu Akizawa⁴, Masakazu Fujii⁵, Yumiko Harigane⁶, Ken-ichi Hirauchi⁷, Osamu Ishizuka⁶, Shiki Machida⁸, Katsuyoshi Michibayashi³, Alessio Sanfilippo⁹, Sani Camilla⁹, Snow E. Jonathan¹⁰, Kenichiro Tani¹¹, Hiroyuki Yamashita¹² (1.Hydrographic and Oceanographic Department of Japan, 2.Japan Agency for Marine-Earth Science and Technology , 3.Nagoya University, 4.Atmosphere and Ocean Research Institute, University of Tokyo, 5.National Institute of Polar Research , 6.Geological Survey of Japan, AIST, 7.Shizuoka University, 8.Chiba Institute of Technology, 9.University of Pavia, 10.Louisiana State University, 11.National Science Museum, 12.Kanagawa Prefectural Museum of Natural History)

[SCG64-06] Petrological characteristics of serpentinized peridotites dredged from oceanic core complexes in the Shikoku Basin

Izumi Segawa¹, *Ken-ichi Hirauchi¹, Yasuhiko Ohara^2,3, Yui Kouketsu³, Katsuyoshi Michibayashi³ (1.Department of Geosciences, Faculty of Science, Shizuoka University, 2.Hydrographic and Oceanographic Department of Japan, 3.Department of Earth & Planetary Sciences, Graduate School of Environmental Studies, Nagoya University)