International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) General Assembly

Location: University of Iceland, Reykjavik, Iceland

Web: http://www.iavcei.org/IAVCEI.htm

Includes the following sessions:

Mantle plumes and plume-ridge interactions

Convenors: B. Bransdóttir (bryndis@raunvis.hi.is), R. Trønnes (r.g.tronnes@nhm.uio.no)

This session is dedicated to geodynamic issues, including mantle convection, the origin and evolution of plumes, mantle melting, melt transport and along-axis melt variability. We seek contributions from all areas of research on mantle plumes, plate-spreading, V-shaped ridges, seamounts, large igneous provinces and orogenic episodes.

This session will focus on:

• Seismic tomography of the mantle aiming at imaging mantle plumes
• Studies of local and regional variations in the depth of seismic discontinuities
• Mineral physics constraints on mantle density as a function of pressure, temperature and composition (compressibility and thermal expansivity)
• Numerical modelling and fluid dynamic experiments on mantle convection and plume generation
• Geophysical features of the oceanic and continental crust, lithosphere and asthenosphere
• Bathymetry and crustal thickness variation, including V-shaped ridges, extent of lateral mantle flow and along-axis variation of melt chemistry
• Geochemical and geophysical constraints on plume-ridge interactions, rift jumps and crustal accretion processes, NE Atlantic and elsewhere
• Geochemical constraints on progressive melting of fertile and refractory mantle sources, plume-related versus ambient asthenosphere or lithosphere

Intraplate volcanism – continents and oceans, from scoria cones to large igneous provinces

Convenors: G. Valentine (gav4@buffalo.edu), A. Kerr (kerra@cardiff.ac.uk)

Intraplate volcanism provides key insights into magma sources and magmatic processes. This volcanism encompasses a wide array of eruptive styles and products, and, on the continents, is an important component of volcanic risk in some areas. This session will combine both the continental and ocean floor perspectives on the nature of ancient and modern intraplate volcanic activity, from source through eruption, on a wide range of scales from small localised eruptions to large igneous provinces.

This session will focus on:

• Asthenospheric vs. lithospheric sources of magmas.
• Time-volume behaviour of intraplate volcanic systems
• Interplay between regional tectonics and volcanism
• Magma chamber processes
• Links between volcanological features and deep plumbing
• Factors controlling eruptive style

Frontiers in large igneous provinces research

Convenors: I. Campbell (ian.campbell@anu.edu.au), R. Ernst (richard.ernst@ernstgeosciences.com)

Over the last fifteen years it has become widely accepted that Large Igneous Provinces (LIPs) are produced by melting mantle plumes.  However the link between LIPs and mantle plumes has recently been challenged.  How confident are we that LIPs are produced by mantle plumes? Are there any aspects of LIPs that cannot be explained by the plume theory?  Are there viable alternative hypotheses? Are there some LIPs that are better explained by alternative models?

This session will focus on:

• Implications of thermocompositional convection for LIPs.
• Seismic imaging of plumes
• Geochronology and eruption rates for LIPs
• Correlation of Proterozoic LIPs (especially their dyke swarms) to test hypotheses of continental reconstruction.
• Can hotspots move?
• Advances in the geochemistry of LIPs
• LIPs as the "pulse of the Earth"

Construction of large igneous provinces and mass extinctions

Convenors: A. Saunders (ads@le.ac.uk), T. Thordarson (thor.thordarson@ed.ac.uk), P. Wignall (p.wignall@see.leeds.ac.uk), S. Self (stephen.self@open.ac.uk), A. Harris (harris@higp.hawaii.edu)

Mass extinctions are global phenomena that represent some of the most dramatic events in the geological history and arguably no events have had more influence on evolution of life on Earth. They are generally thought to have lasted for <1 Myrs and the fact that they define all of our key geological boundaries is the best testimony of their significance. Despite ample research cause of mass extinctions is still one of the great outstanding questions in Geosciences. The synchronicity of mass extinctions and LIP volcanism in the Mesozoic and the Cenozoic has led many to postulate a causal link between the two events. However, the mechanism by which LIP volcanism may have induced mass extinctions is still unclear and strongly debated. In this session we like to focus on the questions: 
Did LIP emplacement lead to dramatic environmental change?
Can LIP volcanism trigger mass extinctions and, if so, how?
The aim is to bring together research that sheds light on the potential climatic and environmental impacts of flood basalt volcanism and their link to mass extinctions via studies of LIP-related stratigraphy as well as shallow subsurface and surface processes involved in construction of LIPs.

The session will focus on:

• Upper crustal plumbing systems of LIPs
• Geochronology and stratigraphy of LIPs
• Eruption styles, mechanisms and lava emplacement modes at LIPs
• Gas fluxes from LIPs and injection into the atmosphere
• Potential climatic and environmental impacts of flood lava eruptions
• Chronological and causal relationships between LIPs and mass extinctions