| 日時: | 2008 年 11 月 18 日(火) 15:00 - 16:00 |
| 場所: |
自然科学総合研究棟 3 号館 506 号室奥のセミナー室, 北海道大学低温科学研究所, 北海道大学理学 8 号館コスモスタジオ, 名古屋大学大学院環境学研究科, 産業技術総合研究所. (ビデオ会議システムを用いて中継予定) |
| 講演者: | Dr. David Baratoux ( Laboratoire Dynamique Terrestre et Planetaire, Observatoire Midi-Pyrenees ) |
| 世話人: | 中村昭子 |
| タイトル: |
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. |