Mud Volcanoes in the Martian Lowlands: Potential Windows to Fluid- Rich Samples from Depth

gases and liquids in the subsurface erupt to the surface, carrying slurries of fluid, mud, and millimeter-to-meter sized rocks [12-14]. The driving force is generally a combination of overpressure and compression. These conditions often occur in orogenic belts and involve hydrocarbon generation, but other mechanisms (e.g. rapid sedimentation with gas hydrate destabilization or clay dewatering) have been suggested as well [12, 14]. 3-D seismic data illustrate the subsurface conduits through which the slurries ascend [15], and these data, coupled with downhole geological, geochemical and biostratigraphic analyses [16-18], demonstrate that rock and mud within surface exposures of mud volcanoes can originate from depths of several kilometers. On Mars, occurrences of mud volcanoes would be important, as they would signal subsurface localities previously, or even presently, rich in volatiles. Of even greater consequence is the possibility that martian mud volcanoes may have transported rocks and sediment from deep, fluid-rich zones to the surface where they could be accessible to future rovers. In this way, mud volcanoes on Mars could provide access to samples from considerable depths that would otherwise be unreachable.