19/10/15 Séminaire Européen: Marjorie Chan (University of Utah)
de 14:00 à 15:00
|S'adresser à||P. Sorrel|
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Sedimentology Frontiers from Earth to Mars: Dunes, Deformation, and Diagenesis
An enticing geologic challenge is applying our knowledge to new exploration settings, using clues and proxies to deduce the processes of sedimentation. Mars has held our interest since ancient times, but now through new technologies and instrumentation advances we have the ability to scientifically explore the Red Planet at unprecedented scales. Studies of sedimentary environments on Earth are critical because terrestrial analogs help us interpret depositional and diagenetic processes, as well as determine where habitable environments for life might exist on other planetary bodies.
Three comparative sedimentary examples of Earth settings show remarkable similarities to recent satellite and rover imagery from Mars:
1. Ergs on Earth are globally important reservoir units for both hydrocarbons and water. Mars has spectacular dune forms and dust devil tracks, reflecting the ubiquitous nature of eolian processes shaping the surface of Mars. Porous dune sediments record the interactions of the atmosphere and the surface, and a history of sand accumulation over time.
2. Soft-sediment deformation has various expressions in eolian units (e.g., contorted cross beds, massive sandstones, and clastic injectites). These can provide clues to past water table conditions and the susceptibility of the sediments to strong ground motion.
3. Colorful sandstones containing iron oxide cements reflecting the mobility of iron in the Earth’s crust. These diagenetic records of past fluid flow histories provide clues about reservoir properties for aquifers and hydrocarbons. Is diagenesis a combination of biogenic as well as physical processes? Many diagenetic relationships suggest a strong link.
Mars is an exciting frontier, offering opportunities for serendipitous discoveries of what might exist within its sedimentary layers and surface landforms.
This talk will close with a brief perspective of new initiatives that will affect how we conduct Earth science in the future.
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