Extension-related processes and rifting in ancient versus modern settings

Convenors; A.H.F. Robertson (University of Edinburgh), G. Manatschal (University Loius Pasteur, Strasbourg), A. G. Leslie (British Geological Survey), R. Corfield (BP), J.-C. Ringenbach (TOTAL)


Objectives of the session: We seek contributions that present new evidence and interpretation of the wide range of tectonic extension-related processes and settings that lead to continental break-up and seafloor spreading, and their recognition in exhumed orogens. Relevant settings potentially include intracontinental rifts, ocean-continent transition zones, backarc basins, spreading ridges and orogenic collapse zones, for all geological time periods (i.e. Precambrian to modern). Evidence may be drawn from any discipline (e.g. geophysical, structural, petrological, sedimentological, paleoceanographic) and may include academic or industry data sets, or both. We welcome contributions that draw on the preserved record of rifted passive margins in collisional orogenic settings (e.g. Appalachian-Caledonides; Alpine; Uralide). We particularly invite papers that discuss topical issues, notably the role of basement structures, their extensional reactivation and importance in tectonic emplacement within exhumed orogens. Contributors are also asked to consider how observational data can help to test or refine existing models (theoretical and conceptual) of extensional deformation of the lithosphere, and the degree to which such models aid the interpretation of collisional margins. Finally, do any of the new data and concepts have potential for resource exploration or exploitation?

Invited speakers:

Maarten Krabbendam (British Geological Survey) Unravelling a Precambrian rift and passive margin sequence: pitfalls and challenges

Per Terje Osmundsen (Norwegian Geological Survey): More Basin and detachment faulting (title to be announced)

M. Pubellier (Ecole Normale Superieure, Paris) , L.S. Chan, W. Chen, N. Chamot-Rooke. From orogenic collapse to rifting ; structures of the South China Sea margin.

Tim Reston (Birmingham University) The extension discrepancy at rifted margin

Jean-Claude Ringenbach (Total), Vivien Bailly, Manuel Pubellier and Julia de Sigoyer (Ecole Normale Supérieure). Circa 7Ma from shortening to collapse in the Lengguru FTB (Papua): a very fast orogenic cycle.