Published by
EDP Sciences
EDP Sciences Journals List
Subscriber Authentication Point
Home All issues Volume 487/ 2 Article
Highlight
Free access
Issue A&A
Volume 487, Number 2, August IV 2008
Page(s) L41 - L44
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:200810150
Published online 01 July 2008



A&A 487, L41-L44 (2008)
DOI: 10.1051/0004-6361:200810150

Letter

Abundance of minerals in the phyllosilicate-rich units on Mars

F. Poulet1, N. Mangold2, D. Loizeau2, J.-P. Bibring1, Y. Langevin1, J. Michalski1, and B. Gondet1

1  Institut d'Astrophysique Spatiale (IAS), Bâtiment 121, 91405 Orsay Cedex, France
    e-mail: francois.poulet@ias.u-psud.fr
2  Interactions et Dynamique des Environnement de Surface (IDES), Bâtiment 509, 91405 Orsay Cedex, France

Received 7 May 2008 / Accepted 24 June 2008

Abstract
Context. Phyllosilicates were definitely identified on Mars by the OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité) instrument onboard the Mars Express spacecraft. The identification, characterization, and mapping of deposits of these minerals hold clues to the potential past habitability. They also constitute a key element in planning for future landing sites.
Aims. To infer the environmental conditions that existed at the time of the formation of these minerals, it is critical to determine if and how the composition of the deposits vary in space and time.
Methods. We applied radiative transfer modeling to the OMEGA reflectance spectra to derive the modal mineralogy (mineral abundances) of some phyllosilicate-rich deposits.
Results. In many outcrops, including the large areas in Nili Fossae, the surface mineralogy is dominated by primary non-altered minerals, with minor fractions of phyllosilicates. These assemblages could result from hydrothermal alteration. By contrast, deposits in the Mawrth Vallis region exhibit a large content of hydrated phyllosilicates, which suggests that the rocks may be mature sedimentary rocks or altered volcanics. Evidence of alteration resulting from metamorphism due to an impact is reported in the central peak of a crater.


Key words: planets and satellites: general



© ESO 2008

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.