Investigating the Origin of Layered Outcrops in the Mawrth Vallis Region

Grant #: NNX12AJ33G
Senior Scientist: Janice Bishop

Objectives: The Mawrth Vallis region contains one of the largest outcrops of layered material, largely dominated by phyllosilicate-bearing rocks and adorned by discordant layering and unusual textures. The goal of this project is to determine the origins of these layered outcrops and test whether sedimentary processes may have contributed to their formation. 

Investigation Summary: We will investigate and document a number of parameters including bedding brightness, bedding thickness, strike and dip, large-scale texture (e.g. polygons), and mineralogy for multiple layered outcrops throughout the Mawrth Vallis region and evaluate these properties in relation to the geologic context of the layered outcrops and their proximity to Oyama crater and the channel. Proposed formation processes for these layered materials include a sedimentary origin, diagenesis, impact-related mechanisms, alteration of volcanic ash, pyroclastic activity and others. We seek to determine the similarities and differences among the phyllosilicate and sulfate-bearing strata as well as differences within the units of these outcrops. We propose to prepare and analyze 8 HiRISE DTMs and 30 CRISM images for this project. This study will compare the properties of layered outcrops at Mawrth Vallis with those of accepted Martian sediments and ancient terrestrial sediments in order to determine if sedimentary processes contributed to formation of layered outcrops in some areas of Mawrth Vallis. 

Significance: Determining the origin of the expansive layered outcrops at Mawrth Vallis would provide clues to the early aqueous processes on Mars. The proposed formation mechanisms rely on different geochemical and geophysical conditions; thus, constraining these will inform the early Martian environment. If sedimentary processes were active at Mawrth Vallis, then that increases the probability that life could have been present here and preserved.