JISCMail - GEO-TECTONICS Archives

A reminder! We would like to bring to your attention the following session to be held at the Fall AGU this year (5-9 December, abstract deadline 8th September). The session, listed under Volcanology, Geochemistry and Petrology, is co-sponsored together with Tectonophysics and Seismology. We are planning the session so it will represent the spectrum from petrology to tectonics and from geochronology to geophysics. We want to bring together a variety of different studies that can address dynamics of orogenic belts from various viewpoints from within the community.

The strength of the deep continental crust relative to the overlying upper crust and underlying upper mantle and its ability to localize strain is a matter of hot debate. Are constant rheology models appropriate? What are the roles of mineral reactions, bulk composition, fluid ingress, magmatism and textural changes in changing the strength of the deep continental crust? How do transient effects interact with longer-term structural inheritance and reactivation? Gaining answers to these and other questions is critical to understanding how deformation in the upper crust, such as are mapped geodetically, couple with tectonics in the mantle. The increased use of quantitative studies of strain partitioning in exhumed deep crustal analogues, together with increased precision of thermo-geochronological methods, and geochemical studies of fluid fluxes have provided better understanding of ancient examples. In modern examples, in situ detection of deformed and deforming crust are increasingly within the reach of seismological experiments and recent experimental data provide better understanding of the relationships between deformation, metamorphism and melting. Consequently it has been of great interest to geoscientists recently to develop multi-disciplinary approaches to understanding deformation through the continental lithosphere and the role of the deep crust in coupling mantle to upper crustal deformation. For fall AGU 2005 we invite submissions on this topic to the special session to Volcanology, Petrology and Geochemistry with co-sponsorship by Tectonophysics and Seismology. We will bring together a variety of studies that can address dynamics of orogenic belts from different viewpoints, including geochemical and structural approaches together with insights from seismology and numerical modelling. We anticipate that the session will attract interest across the spectrum from petrology to tectonics and from geochronology to geophysics, and that it will include contributions from field-based research, experiments and geodynamic modeling.