HR: 1340h
AN: P13B-1297    [Abstracts]
TI: Fluidization of Dry Material on Martian Gullies
AU: * Cedillo-Flores, Y
EM: yolanda@soho.igeofcu.unam.mx
AF: Departamento de Fisica Espacial, Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria. Circuito de la Investigacion, Mexico, DF 04510, Mexico
AU: Durand-Manterola, H J
EM: hdurand_manterola@yahoo.com
AF: Departamento de Fisica Espacial, Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria. Circuito de la Investigacion, Mexico, DF 04510, Mexico
AU: Craddock, R A
EM: cradockb@si.edu
AF: Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, 6th and Independence Av. SW. Washington D.C, Washington, DC 20560, United States
AB: Since their discovery many different theories have been put forward to explain the origin of Martian gullies. Each theory has certain weaknesses, however, and the formation of these features remains poorly understood. Distinctive morphologic variations exist that have often been ignored. Here we present experimental results that attempt to create Martian gullies through gaseous fluidization of CO2 using mixtures of dry granular material and CO2 ice. Using Mars Orbiter Camera (MOC), Thermal Emission Imaging System (THEMIS) and High Resolution Imaging Science Experiment (HiRise) 28 images and data, we identified 12 gullies with morphologic characteristics similar to those produced from our experiments. These gullies range occur at mid-latitude regions (33° to -71°) and at a range of elevations (-4800 to 2700 meters). Based on our experimental data and observations, we suggest that the formation of at least some gullies may be analogous to pyroclastics flows but colds. On Mars such flows may result from the accumulation of CO2 ice and dust on slopes during the winter. Increases in temperatures during the spring may cause the CO2 ice to sublime initiating slope failure and mass- wasting. The different elevation and latitudes in which we found gullies suggest that their existence can be explain by our model. Our scenario allows the formation of gullies in recent times and to a more extensive rank of latitude of what predict the models that require the liquid water presence. Our model also explains the occurrence of gullies at different orientations, temperatures, altitudes and probably different materials and slopes. We conclude that similar geomorphic features can be formed by different mechanisms, for example: gullies are formed by water flow on Earth but experiments results suggest that dust fluidization could be a valid mechanism on Mars.
DE: 5400 PLANETARY SCIENCES: SOLID SURFACE PLANETS
DE: 5419 Hydrology and fluvial processes
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting