Clay minerals on Mars: updated views on distribution, mineralogy and geologic context

Joe Michalski, Earth Sciences Department, NHM

Earth Sciences Seminar Room (Basement, WEB 05, the previous Mineralogy Seminar Room)

Tuesday 13th January, 1600h

While some Martian meteorites contain minor abundances of clays formed on Mars, most of our understanding of the clay mineralogy of Mars comes from orbital infrared remote sensing measurements. The European Space Agency’s Mars Express spacecraft was, in 2004, the first mission to detect clay minerals on Mars. Since that time, both Mars Express and NASA’s Mars Reconnaissance Orbiter have detected >10,000 deposits spanning a range of geologic contexts and mineralogies. These deposits are extremely interesting for many reasons, not the least of which is that they seemingly date to an era not preserved on Earth (>3.7 Ga). 

In this talk, Joe will describe an updated perspective on the mineralogy of Martian clays, and their implications for ancient aqueous geological processes on and habitability of Mars.

More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/

What was the role of water on Mars in the past?  Much of what we know about Mars has been from observation from a distance. Although a few missions have landed scientific equipment on the surface, and some meteorites from Mars have landed on the Earth's surface, a huge amount of data have been gathered from orbiting missions and from other remote observation techniques. The geology of the surface can be studied by looking at infrared and other radiation: different minerals react differently to particular sorts of light and radiation.

Javier Cuadros, a clay specialist in the Museum's Mineralogy Department, has been successful in being awarded money from the EU to host a research fellow under the Marie Curie scheme to explore the origin of Iron/Magnesium-rich clay minerals on Mars.

Clays have been discovered on Mars in the past five years using near-infrared spectroscopy - this is of particular importance because the presence of clay shows for the first time unambiguous evidence for long-term water activity on Mars. Understanding the conditions of formation of these
Fe/Mg-rich clays is central to revealing Mars' climate history; and the possiblity of there having been conditions suitable for life in the past .

The study will focus on marine systems on Earth that produce abundant Mg- and Fe-rich clays (talc, saponite and nontronite). These clays are often intimately mixed by chemical and physical processes and seem similar to Martian clays. It seems possible that similar water conditions on Mars may have generated the Fe/Mg-clays. The Earth clays from several submarine hydrothermal fields will be studied using advanced microscopy, chemical, spectroscopic, structural and isotope analytical techniques to fully characterise their crystal-chemistry and to define the environment in which they formed (temperature, fluids, mineral assemblages).

These infrared and other data for Earth clay will be compared with the data from Mars and similarities and differences will give much better understanding of the past role of water on Mars.