date: 2008 Nov 18(Tue) 15:00 - 16:00
room: Kobe University, Shizen Bldg. #3, room 508,
Institute of Low Temperature Science Hokkaido University,
Hokkaido University, Science Bldg. #8, Cosmo-studio,
Graduate School of Environmental Studies in Nagoya University,
National Institute of Advanced Industrial Science And Technology.
(This seminar is a teleconference by the use of video-conferencing system.)
speaker: Dr. David Baratoux (Laboratoire Dynamique Terrestre et Planetaire, Observatoire Midi-Pyrenees)
organizer: Dr.Akiko Nakamura (Kobe University)
title: Syrtis Major, Tharsis Montes and Central Elysium Planitia
What do these three volcanoes tell us about the volcanic history of Mars?
abstract: Exploration programs of the red planet generally focus on *water on  Mars*. Here, I will focus on its volcanic history. A selection of three volcanic regions will illustrate how fundamental questions can be raised by local observations. I will present a method to infer from impact craters a 3-D view of the composition of a large volcano (using spectrum from OMEGA/Mars Express data). Chemical and mineral compositions can be then compared to possible melt compositions produced from partial melting of the martian mantle, inferring the depth of the source of the magma. Ages of volcanic landforms are, in some cases, as young as only a few million years, suggesting the possibility of ongoing volcanic activity. The characteristics of this recent volcanism will be presented, focusing on significant differences with large igneous provinces on Earth. In addition, very fluid lavas on Mars were formed in this context of recent volcanic activity, which is not understood. Comparing these different situations raises questions concerning the mechanism(s) responsible for volcanism on Mars throughout its history. Back to *water on Mars*, I will conclude emphasizing that a comprehensive view of the volcanic history of Mars is actually a necessary step before understanding the history of volatiles responsible for the alteration of magmatic rocks.