23-rd Annual VM Goldschmidt Conference

Start Date: 
Sunday, August 25, 2013
End Date: 
Friday, August 30, 2013

Location: Firenze Fiera Congress Centre, Florence, Italy

Web: http://goldschmidt.info/2013/index

Includes the following sessions:

01e: Causes of Phanerozoic mass extinctions: impacts vs. large igneous provinces vs. others?

Convenors: Fred Jourdan (f.jourdan@curtin.edu.au), Andrea Marzoli (andrea.marzoli@unipd.it), Simonetta Cirilli (simocir@unipg.it)

The history of life on Earth is punctuated by several instances of sudden drops in biodiversity where a large number of species were wiped out, followed by biotic recovery, rapid evolution and dramatic shifts in dominant life forms. Though this phenomenon is well known, the root cause(s) of these mass extinctions is/are yet unsolved and controversial. Multiple causes have been advanced to explain sudden extinctions. Currently, the two dominant contenders are high velocity extraterrestrial bolides and large volcanic eruptions. Discussions of these two hypotheses have been recently quite polarized. Nevertheless, critical to evaluate the potential role of volcanism and asteroid impact (as well as other hypotheses) in causing mass extinctions are (1) precise temporal correlations with the stratigraphic boundaries, (2) well understood mechanisms that could alter Earth’s climate (e.g. gases from target rock vaporization or volcanogenic emission) and (3) effects of the climate changes on the biosphere. In this session, we are encouraging submission from proponents of the volcanism, asteroid impact, and any other mechanisms that could potentially explain the Phanerozoic mass extinctions. In particular, we are seeking contributions from stratigraphy, geochronology, geochemistry, physical modelling and climate studies.

Keynote speaker: Paul Wignall (University of Leeds)

06f: Continental magmatic pipeline: from crustal roots to the surface

Convenors: Karl Cooper (kmcooper@ucdavis.edu), Jonathan Miller (jonathan.miller@sjsu.edu), Josef Dufek (josef.dufek@eas.gatech.edu)

This session will focus on magmatic processes in continental sectors and their role in continental crustal evolution, addressed through a variety of approaches including petrological studies, mineral chemistry and geochronology, and numerical and/or laboratory modeling of magmatic systems. Broad topics covered in this session will include the role of deep vs. mid- to shallow-level magmatic plumbing systems in controlling silicic magmagenesis and/or the composition of continental crust and the relationship of the thermal structure and chemical differentiation of the continents. We welcome submissions covering diverse topics and approaches within this broad context, including for example: multi-disciplinary studies combining textures, chemistry, and ages, including mineral chemistry and geochronology; the role of crystal mush vs. solidified magmas (i.e., thermal histories of reservoir systems); magma mixing processes and efficiency; thermobarometry of crystals and magmas; and evidence for silicic magmagenesis by deep-seated vs. upper-crustal differentiation processes.

11c: Crustal assimilation during magma emplacement

Convenors: Luigi Dallai (dallai@igg.cnr.it), Valentin Troll (vrtroll@gmail.com)

The chemical compositions of plutonic and/or volcanic rocks (solidified magma) are generally used to constrain the compositions of the source from which the magmas were originally formed, and the physical conditions of melt generation. However, the compositions of magmas change as they ascend through the lithosphere in response to closed-system (fractional crystallization), and/or open-system (crustal contamination, magma mixing) behavior of the igneous bodies. The session focuses to the mechanisms producing chemical as well as isotopic variations, in order to resolve mantle vs. crustal contributions, and to quantify the elemental fluxes associated with such processes. The fundamental question to be addressed is how and to what extent the chemistry of igneous systems reflects source composition, or it has been modified during their ascent to shallow level magma reservoirs and volcanic extrusions/explosions. We therefore welcome insights provided by the re-interpretation of data from classical measurements and by novel isotope-geochemical techniques, and their meaning in the geological framework.

Florence, Italy