American Geophysical Union (AGU) Fall Meeting

Start Date: 
Monday, December 13, 2010
End Date: 
Friday, December 17, 2010

Location: Moscone Convention Center, San Francisco, USA

Web: http://www.agu.org/meetings/fm10/

Includes the following sessions:

T05: Interaction between magmatic and tectonic processes in continental and incipient oceanic rifts

Convenors: Derek Keir (d.keir@leeds.ac.uk), Carolina Pagli (c.pagli@leeds.ac.uk), Juliet Biggs (juliet.biggs@earth.ox.ac.uk), Eleonora Rivalta (e.rivalta@leeds.ac.uk)

A key breakthrough in the last decade is recognition of the intimate linkage between extensional deformation and magmatism during rupture of the continents. However, the nature of this relationship at all depths through the lithosphere and its evolution through time remain controversial. We invite contributions from observational and modelling studies that constrain the length, time scales and mechanisms of magma transport and emplacement in continental and incipient oceanic rifts. We also welcome contributions on interactions between magmatism and other deformation mechanisms (e.g. faulting and ductile stretching) and their response to rheological controls.

T06: Structure, dynamics, and evolution of the African-Arabian rift systems

Convenors: Derek Keir (d.keir@leeds.ac.uk), Ian Bastow (ian.bastow@bristol.ac.uk), Christel Tiberi (christel.tiberi@gm.univ-montp2.fr), Cecile Doubre (cdoubre@uinstra.fr)

The Red Sea, Gulf of Aden and rifts of the Afar volcanic province have developed since Palaeogene times during the removal of the Arabian plate from Africa above anomalously warm mantle: the African superplume. The geological record of the region exhibits active extensional systems ranging from the early stages of breakup to sea-floor spreading, and thus the development of young passive margins. We invite contributions from geoscientific studies that help constrain structure and dynamics of crust and mantle beneath the region. We also invite contributions from studies that address linkages between mantle dynamics, lithospheric extension and magmatism.

T20: Investigation of the Earth’s interior using geophysical and laboratory measurements

Convenors: Anne Pommier (apommier@mit.edu), Robert Evans (revans@whoi.edu)

Physical properties, such as electrical resistivity, seismic velocity, viscosity and density of melts, minerals and fluids, are the filter through which geophysical models attempt to constrain geodynamic processes. These constraints can only be as good as our understanding of how the physical properties measured vary as functions of Earth's temperature, pressure and composition. Laboratory measurements, therefore, provide the vital information through which geophysical interpretations are made, and also mark the limits of interpretational ability. We invite contributions that emphasise a laboratory-field multidisciplinary approach in furthering geological understanding.

V25: Generation and evolution of alkaline to sub-alkaline magmas

Convenors: Romain Meyer (mail@romain-meyer.eu), Sebastien Pilet (sebastien.pilet@unil.ch), Etienne Medard (e.medard@opgc.univ-bpclermont.fr), Ralf Gertisser (r.gertisser@esci.keele.ac.uk)

This session is designed to bring together multiple disciplines to understand the generation and evolution of alkaline to sub-alkaline magmas observed in rift volcanic systems and intraplate settings. This session will include discussion on the mechanism of magma generation (asthenospheric vs. lithospheric), on source characteristics (implication of recycled material, metasomatism, crustal anatexis), and on processes related to the chemical evolution of these magmas from mantle depths to shallow level (fractional crystallisation, assimilation, magma mixing). We encourage contributions that explore new petrogenetic scenarios using field observation, petrological constraints as well as geophysical observations or numerical modelling.

V37: Are hotspots hot?

Convenors: Gillian Foulger (g.r.foulger@durham.ac.uk), Peter Clift (p.clift@abdn.ac.uk), James Natland (jnatland@rsmas.miami.edu)

An anomalously hot mantle source is a requirement of the plume hypothesis, but not of the shallow plate hypothesis. Whether or not the temperature beneath "hotspots" is unusually high is a matter of current dispute. Methods used to measure mantle temperature include seismology, petrology, heat flow, and modelling ocean-floor topography, e.g., swells. A critical underpinning of these efforts is the thermal structure of the mantle, including the thickness of the surface conduction layer and expected lateral variations. This session solicits contributions, from all subdisciplines, that bear on estimating the temperature of the mantle beneath "hotspots". A diversity of viewpoints is anticipated and session time will be allocated to discussion.

City: 
San Francisco, USA