S63: Water in the early Earth

Conveners:	Stephen Mojzsis	(mojzsis@colorado.edu)
	Alessandro Morbidelli	(Alessandro.morbidelli@obs-nice.fr)
Keynote:	Yukata Abe	(Tokyo)

Water is abundant on Earth compared to the other terrestrial planets; it is present in most rocks down to trace quantities, and is the sine qua non of life as we know it. New advances in our understanding on the source(s) of water to Earth at time of formation as well as a growing realization of the widespread role of water in the crust in the first 1000 million years of Earth history have provided valuable and surprising new insights into the nature of what constitutes a habitable world around a young solar-type star.

This session seeks contributions that explore the origin, incorporation and transformation of water in the Early Earth. Special emphasis will be on arguments for and against exogenous (comets, dust) vs. endogenous (planetesimal) water and geochemical evidence bearing on hydrosphere/lithosphere/atmosphere interactions in the first 20% of Earth history.

S64: Earth's deep water cycle

Conveners:	Erik Hauri	(hauri@dtm.ciw.edu)
	Hans Keppler	(Hans.Keppler@Uni-Bayreuth.De)
Keynote:	Erik Hauri	(Washington)

The Earth¥s mantle is a major water reservoir in dynamic exchange with the surface of the planet over geologic time. We invite contributions from field and laboratory studies aiming at quantifying the distribution of water in the mantle, the rate of water subduction and degassing, as well as studies on the influence of water on mantle dynamics and melt generation. Presentations of numerical models that aim to integrate several of these aspects are particularly welcome.

S65: Water and volatiles in volcanic processes

Convener:	David Pyle	(David.Pyle@earth.ox.ac.uk)
Keynote:	Jon Blundy	(Bristol)

Volatile constituents of melts and their source regions control the formation, evolution and ultimate fate of magmas - whether erupted, or not. But the eruptive products present us with a challenge since they usually contain only residual traces of these fugitive species. We seek contributions which shed light on any of the roles of volatiles in volcanic processes; from studies of solidified volcanic products, to measurements of gaseous emissions and models which seek to inform these diverse approaches.

S66: Fluid properties at high pressure and temperature

Convener:	Craig Manning	(manning@ess.ucla.edu)
Keynote:	Thomas Driesner	(ETH Zürich)

Water-rich fluids play a fundamental role in the physical and chemical evolution of planetary bodies. In the solid Earth, aqueous solutions mediate geochemical cycling and tectonic processes. High P and/or T fluids have also participated in the physical and chemical evolution of Mars, the icy satellites of Jupiter and Saturn, and asteroid parent bodies. This session will focus on experimental and theoretical constraints on aqueous geochemistry at high P and/or T relevant to a wide range of planetary problems. We welcome contributions involving fluid equations of state, speciation, isotope geochemistry, kinetics and thermodynamic and physical properties.

S67: Water on Mars

Convener:

Jutta Zipfel

(jzipfel@senckenberg.de)

Liquid water is absent on the surface of Mars today. Yet studies of Martian meteorites showed traces of secondary minerals formed under the presence of water. Advances through exploration programs to Mars revealed waterís past activity at a large scale. Surface morphology and rocks that are either sedimentary in origin or weathered by aqueous fluids give evidence for a hotter and wetter climate on Mars in its past. The understanding of timing, extent, and interaction with water bears fundamental information on climate changes and potential development of life, as we know it, on Mars.

This session seeks contributions that explore the chemical evidence for the presence of water on Mars either from meteorites or space exploration data. Special emphasis will be on arguments for timing, amount and extent of liquid water on Mars and its interaction with surface rocks.