Includes the following sessions:
TS8.1 Plate tectonics, mantle plumes, and beyond: the legacy of W. Jason Morgan
Convenors: Jason Morgan (jason@sustc.edu.cn), Karin Sigloch (Karin.SIGLOCH@univ-cotedazur.fr), Hans-Peter Bunge (bunge@lmu.de), Joao Duarte (jdduarte@fc.ul.pt), Ya-Nan Shi (shiyn@sustech.edu.cn)
In this session we want to celebrate the scientific achievements of W. Jason Morgan, the discoverer of Plate Tectonics and Mantle Plumes, while looking into the future developments of the scientific revolution that he helped to ignite. Fifty years after their discovery, we still have basic questions in our understanding of how Plate Tectonics and Mantle Plumes are linked to the flow structure of the mantle, heat loss from Earth's core, and Earth's evolution from its accretion to the present day. Inspired by these concepts, the modern subdisciplines of Tectonics, Geodynamics, Seismology, Geochemistry, and Earth Magnetism/Rock Physics continue to grapple with gaining a deeper understanding of our planet. Here we welcome contributions that highlight recent progress and problems in this endeavor.
GD2.1 Geochemical and geodynamic perspectives on the origin and evolution of deep-seated mantle melts and their interaction with the lithosphere
Convenors: Igor Ashchepkov (igor.ashchepkov@igm.nsc.ru), Sonja Aulbach (s.aulbach@em.uni-frankfurt.de), NV Chalapathi Rao (nvcrao@bhu.ac.in), Evgenii Sharkov (sharkov@igem.ru), Natalia Lebedeva (namil@mail.ru)
The origin and evolution of the continental lithosphere is closely linked to changes in mantle dynamics through time, from its formation through melt depletion to multistage reworking and reorganisation related to interaction with melts formed both beneath and within it. Understanding this history is critical to constraining terrestrial dynamics, element cycles and metallogeny. We welcome contributions dealing with: (1) Reconstructions of the structure and composition of the lithospheric mantle, and the influence of plumes and subduction zones on root construction; (2) Interactions of plume- and subduction-derived melts and fluids with the continental lithosphere, and the nature and development of metasomatic agents; (3) Source rocks, formation conditions (P-T-fO2) and evolution of mantle melts originating below or in the mantle lithosphere; (4) Deep source regions, melting processes and phase transformation in mantle plumes and their fluids; (5) Modes of melt migration and ascent, as constrained from numerical modelling and microstructures of natural mantle samples; (6) Role of mantle melts and fluids in the generation of hybrid and acid magmas. These topics can be illuminated using the geochemistry and fabric of mantle xenoliths and orogenic peridotites, mantle-derived melts and experimental simulations.
GD1.2 Structure, origin, and evolution of intraplate magmatism in space and time: insights from petrological, geochemical and geophysical studies
Convenors: Martha Papadopoulou (mp589@le.ac.uk), Jordan Phethean (j.phethean@derby.ac.uk), Magdalena Matusiak-Malek (magdalena.matusiak-malek@uwr.edu.pl), Matthew Comeau (M.J.Comeau@tudelft.nl)
The introduction of the plate tectonics theory in the 1960s has been able to satisfactory explain ~90% of the Earth’s volcanism, attributing it to either convergent or divergent plate boundaries. However, the origin of a significant amount of volcanism occurring on the interior of both continental and oceanic tectonic plates – widely known as intraplate volcanism – is considered to be unrelated to common plate boundary processes. A variety of models have been developed to explain the origins of this enigmatic type of magmatism. With time, technological breakthroughs have enabled improvement of instrumentation, resolution, and numerical modelling, as well as the development of new techniques that allow us to better understand mantle dynamics in the Earth’s interior. This technological improvement has helped re-evaluate and refine existing models and develop new models on the origins of intraplate magmatism. These models in turn, provide better insights on processes at depth, and also shed light on the complex interactions between the mantle and the surface. Understanding what triggers magmatism away from plate boundaries is critical to understand and reconstruct the evolution of Earth’s mantle through time, especially in eras where the tectonic plates weren’t yet developed or when the surface of the Earth was dominated by supercontinents. Moreover, deciphering the origins of intraplate magmatism on Earth can give us invaluable knowledge towards understanding magmatism on other planetary bodies in the solar system and beyond.
We welcome contributions dealing with the origins and evolution of intraplate magmatism using a variety of approaches and techniques to tackle outstanding questions, such as but not limited to: petrological, geochemical, geochronological and isotopic data, geophysical and geodynamical analysis, and seismological data. The aim of the session is to bring together scientists looking to understand intraplate magmatism using different approaches and to enhance discussion and collaboration between the various disciplines.