Continental rifting is a multi-facetted process spanning from the inception of extension to continental rupture or the formation of a failed rift. This session aims at combining new data sets, concepts and techniques elucidating the structure and dynamics of rifts and rifted margins. We invite submissions highlighting the time-dependent evolution of processes such as initiation of faults and ductile shear zones, tectono-magmatic and sedimentary history, lithospheric necking and rift strength loss, influence of the pre-rift lithospheric structure, mantle dynamics and associated effects on rifting processes, as well as continental break-up and the transition to sea-floor spreading. We encourage contributions using multi-disciplinary and innovative methods from field geology, geochronology, seismology, geodesy, marine geophysics, plate reconstruction, or modeling. Focus regions may include but are not limited to the Atlantic, Indian Ocean, Mediterranean and South China Sea (e.g. IODP 367/368 area) rifted margins, or the East African, Eger, Baikal and Gulf of California rift systems. Special emphasis will be given to presentations that provide an integrated picture by combining results from active rifts, passive margins, failed rift arms or by bridging the temporal and spatial scales associated with rifting.
Cross-disciplinary investigations of extensional systems
What controls lithosphere evolution during extension? The aim of this session is to investigate diverging systems over a wide range of spatial and temporal scales, and at all stages in the life cycle of divergent plate boundaries including continental rifting, mantle exhumation and seafloor spreading.
A special emphasis will be given to
(1) studies that couple lithospheric deformation models to plate kinematics, and that integrate possibly the role of serpentinisation and/or magmatism in the models.
(2) works that analyse subsidence and thermal effect of rifting and break-up.
(3) paleogeographic reconstructions revealing the influence of sedimentation and lithosphere structure evolution on biogeochemical cycles and oceanographic circulation.
(4) contributions that elucidate extensional modes through the interplay between tectonic structures, magmatism and the stratigraphic record using field, petrological and seismic data.
Volcanic versus non-volcanic rifts and passive margins, from rift to ridge
New observations and modeling allow us to investigate the underlying processes responsible for volcanic and non-volcanic rift and passive margin formation. Key questions to be resolved include 1) what controls the amount and distribution of magmatism during volcanic to non-volcanic rift and passive margin formation. 2) How does magmatism impact the tectonic evolution of these systems and what are the structural and rheological controls of magmatism and feedbacks on tectonic deformation. 3) How are structural style of passive margin formation and magmatism linked? 4) What are the consequences of magmatic versus a-magmatic systems for the associated sedimentary basins? 5) What is the depositional environment for formation of seaward dipping reflector sequences and which processes control anomalous vertical motions during basin evolution? We encourage abstracts that offer new insights into processes underlying volcanic and non volcanic rift-passive margin formation from rift to ridge, using constraints from observations and modeling.
Rifted margins: Geological and geophysical observations, interpretations and their uncertainty with respect to the understanding of their evolutions and architectures
The integrated study of field (young, and ancient analogues preserved in orogenic systems), seismic reflection/refraction, gravity/magnetics, well data (exploration and IODP), analogue and thermo-mechanical modelling approaches have greatly improved our understanding of the processes that influence and modify the architecture (crustal, magmatic, sedimentary, structural and thermal) of the distal domain of rifted margins. As more data becomes available our appreciation of the 3D and ultimately 4D geodynamic processes that influence the formation and present day structure of distal margins is evolving. Although all rifted margins are somewhat unique, similar genetic processes are often proposed despite the underlying interpretational uncertainties. These uncertainties can impact the resulting interpretations relating to the tectono-magmatic and crustal models. Therefore, despite many models the process often remains controversial and/or far for being well constrained.
This session would like to explore and discuss the observations and interpretations derived from geological and geophysical datasets across rifted margins and distal margins. Importantly, uncertainties should be addressed with respect to our current understanding of the genetic rift-domain evolution. Observations should focus on the evidences for processes that impact the final architecture, rock content and thermal imprint of conjugate margins. This relates to the observed style of extension and thinning (high vs low angle faulting and static vs dynamic interpretations and their evidence), vertical motions (e.g. uplift and subsidence), the isostatic impacts of the tectonic, magmatic and stratigraphic history relating to the genetic-rift domains.