TS5.2/GMPV5.12 Tectonic and magmatic processes in extensional settings. Insights from cutting-edge seismic data, Iceland, East Africa, the South China Sea, and beyond (co-organized) |
Convener: Craig Magee | Co-Conveners: Peter Clift , Rebecca Bell , David Iacopini , Giacomo Corti |
Continental break-up is commonly associated with the development of normal faults, the formation of sedimentary rift basins, and magmatic activity. Interactions between these processes control rift basin structure and the geometry and connectivity of magma conduits and reservoirs, influencing the entire margin evolution and the transition to seafloor spreading. Defining 3D rift architecture and plumbing system structure can therefore provide important insights into: (1) stages of continental break-up; (2) the distribution of rift-related sediment routing systems; (3) the chemical evolution of magma and its migration through the lithosphere; (4) host rock deformation induced by magma movement; (5) volcanic eruption locations and styles; (6) subsurface fault zone structure and fluid–rock interaction and their seismic imaging; and (7) petroleum system evolution. However, limitations in exposure at the Earth's surface makes reconstructing rift structure and magma plumbing systems challenging. It is therefore important to integrate field observations with subsurface data. In areas of active continental break-up or oceanic spreading, indirect analytical approaches commonly involve: (1) ground deformation data (e.g., InSAR and GPS); (2) petrological and geochemical data; and/or (3) mapping both or structures, rock types and melt using geophysical techniques such as potential field, magnetotellurics and seismicity. Conversely, seismic reflection data has revolutionized our understanding of rift basin structure and magma plumbing systems in passive margin settings. This session aims to bring together a range of Earth Scientists, who employ different techniques, to discuss magma-tectonic interactions observed in areas of active or ancient lithospheric extension. We particularly welcome contributions that asses various magma-tectonic processes, using different geological and geophysical techniques, occurring during the active break-up of East Africa or Iceland or the ancient extension and subsequent evolution of rifted margins (e.g., the South China Sea). We are particularly interested in works that attempt to bridge the gap between active and ancient break-up studies and utilise seismic reflection data.