Web: http://www.jpgu.org/meeting_e2020/
Includes the following sessions:
S-IT32. Do plumes exist?
Convenors: Hidehisa Mashima (hisa.mashima@mbn.nifty.com), Gillian Foulger (g.r.foulger@durham.ac.uk), Dapeng Zhao (zhao@tohoku.ac.jp)
The debate regarding whether anomalous volcanic areas on Earth's surface are fed by deep-mantle plumes is widely considered to be the most significant debate currently ongoing in Earth science. Not only does the debate touch on a fundamental aspect of how Earth works dynamically, but the subject is extraordinarily cross-disciplinary to an extent that probably few scientists fully realize. Sub-disciplines that can contribute to efforts to resolve the debate include sedimentology, palaeontology, tectonophysics, geochronology, volcanology, petrology, geochemistry, geothermal research, seismology, geodesy, electromagnetics and many others.
In addition to the disciplines of Earth science, the plume debate provides a remarkable and thought-provoking subject for scientific philosophy and reflections on correct scientific methodology: (1) What exactly is a plume? People often change their definition of a plume a posteriori in order to fit their observations. (2) How can the plume- or the plate hypothesis be falsified? (3) Do Earth scientists tend to present only one possible interpretation of their data, or do papers reflect all possible interpretations? Unfortunately, the former is often the case. (4) Are published interpretations consistent with other data from the subject field area? Often they are not, and the inconsistencies are not sufficiently highlighted nor discussed. These issues are particularly useful for inducting students into correct scientific working. In summary, the debate provides enormously fertile ground for new, fundamental questions and cross-disciplinary research.
This session welcomes studies of melting anomalies on Earth from the point of view of any sub-discipline. We also welcome studies of geological phenomena which are attributed to mantle plumes, such as back-arc extension, plate motion, sedimentary basin formation and lithospheric uplift, and any other work that bears on this fascinating and challenging geological debate.
S-MP37. Supercontinents and crustal evolution
Convenors: Madhusoodhan Satish-Khan (satish@geo.sc.niigata-u.ac.jp), Krishnan Sajeev (sajeev@ceas.iisc.ernet.in), Tomokazu Hokada (hokada@nipr.ac.jp), Yasuhito Osanai (osanai@scs.kyushu-u.ac.jp)
Supercontinent formation and dispersion has been enigmatic in the Earth's history. Eurasia is one such current supercontinent and incredible progress in the understanding of its geological evolution has been achieved in the past decades. Earlier supercontinents in the Earth's history such as Gondwana (0.5 Ga), Rodinia (1.0 Ga), Columbia/Nuna (2.0 Ga), Kenorland (2.5 Ga) and Vaalbara (3.1 Ga), have been the focus of several studies, however limited information on older supercontinents has restricted in understanding their tectonic evolution. Several important unsolved issues remain, such as how, when and where these supercontinents formed and how long they remained as such before breaking apart. Additional questions arise on the processes that triggered the fragmentation and unification of continents. In this session, we invite authors around the world to present original new data as well as review results on the continental scale crustal processes and tectonic evolution that are associated with supercontinent formation events in Earth's history. The well-studied Eurasia and Gondwana supercontinents are of particular focus. Topics of interest include, but not restricted to, extremes in metamorphism, P-T-d-t evolution, magmatism, and the role of fluids. We hope to provide a platform for scientific discussions that will enlighten our understanding of the physical and chemical processes in the continental crust that records episodes of orogenesis that contributed to the formation and evolution of supercontinents.