| Union(U) |
|---|
| Session Sub-category | Union |
| Session ID | U-02 |
| Title | Pacific-type orogeny: From ocean to mantle |
| Short Title | Pacific-type orogeny |
| Main Convener | Name | Inna Safonova |
| Affiliation | Novosibirsk State University |
| Co-Convener 1 | Name | Tatsuki Tsujimori |
| Affiliation | Tohoku University |
| Co-Convener 2 | Name | Yukio Isozaki |
| Affiliation | Department of Earth Science and Astronomy, Multi-disciplinary Sciences - General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo |
| Co-Convener 3 | Name | Tsuyoshi Komiya |
| Affiliation | Department of Earth Science & Astronomy Graduate School of Arts and Sciences The University of Tokyo |
| Session Language | EE |
| Scope | Pacific-type convergent margins (ocean - continent) and their related orogenic belts exist/form over subduction zones, which are the only ways to deliver surface materials to the deep mantle. Pacific-type orogens keep records of the evolution of paleo-oceans, formation and transformation of continental crust at their active margins, and generation of hydrous-carbonated plumes in the mantle transition zone (MTZ) and its related intra-plate magmatism. An approach linking paleo-oceans, active margins and plume magmatism stands on three "whales": the model of Ocean Plate Stratigraphy (OPS), the parameters of active convergent margins and the model of hydrous-carbonated plumes. The OPS model was created by many detailed studies of western Pacific, in particular Japanese, accretionary complexes; it allows recognizing different oceanic plates within one paleo-ocean and evaluating their sizes and ages. Pacific-type convergent margins are places of major continental growth by island-arc juvenile magmatism and accretion, but they are also places of strong plate interactions and crust destruction. There are two contrast types of those margins: accreting ones accompanied by the formation of accretionary complexes, and eroding ones accompanied by the tectonic and subduction erosion of accretionary wedge, fore-arc prism and volcanic arc. The materials of oceanic and continental crust, which are eroded at Pacific-type convergent margins, can accumulate in the MTZ and affect mantle conditions. All those processes, the subduction of hydrated and carbonated oceanic crust, the destruction of continental crust at eroding margins, and the accumulation of mafic and sialic materials in the MTZ can synergistically trigger the generation of hydrous-carbonated mantle plumes in the MTZ, mantle melting and upwelling, and intra-plate continental magmatism. We welcome papers on results from Pacific-type orogenic belts worldwide and from Archean to Cenozoic ages. |
| Presentation Format | Oral and Poster presentation |
| Invited Authors | - Shigenori Maruyama (Earth-Life Science Institute, Tokyo Institute of Technology)
- Yukio Isozaki (Department of Earth Science and Astronomy, Multi-disciplinary Sciences - General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo)
- Eiji Ohtani (Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University)
- Inna Safonova (Novosibirsk State University, Sobolev Institute of Geology and Mineralogy SB RAS)
- Konstantin Litasov (V.S. Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russia)
- Dapeng Zhao (Department of Geophysics, Tohoku University)
- Min Sun (University of Hong Kong)
- Tatsuki Tsujimori (Center for Northeast Asian Studies, Tohoku University, Department of Earth Science, Tohoku University)
|
