DESCRIPTION OF NOACHIAN-HESPERIAN GEOLOGIC CONTACT AT NE SYRTIS MAJOR PLANUM, MARS

The current method for determining the relative ages of Martian stratigraphy is by quantitatively assessing crater density. Although this is a proven accurate method, we have the tools to be more precise in determining what exactly the differences between the geologic epochs on Mars are. This project utilizes the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to study mineralogy and soil types over an area that spans two separate geologic epochs, the Noachian (4.6 – 3.7 GA) and the Hesperian (3.7 – 3.0 GA). It also uses the High Resolution Imaging Science Experiment (HiRISE) to view stratigraphic and regolith differences across that contact. Both of these instruments are part of the science payload of the Mars Reconnaissance Orbiter (MRO) which began its primary science phase in November 2006. Data products created by the CRISM and HiRISE teams are analyzed, and new data products from the copious data generated by these instruments are created.

The study area is NE Syrtis Major Planum. It has been advocated by some areologists as a future landing site for the Mars Exploration Program (MEP) because of the presence of many geologically interesting features such as altered carbonate and serpentine, unaltered Noachian ultramafic rock, polyhydrated sulfate deposits, Fe/Mg and Al phyllosilicates, unaltered Hesperian Syrtis lavas, and fluvial channels. All of these science targets are compelling to MEP’s main directive to “follow the water.” The study area straddles the Etched Noachian Plain (Nple) and the Hesperian-aged Syrtis Major Formation (Hs) geologic units.

CRISM data is analyzed using remote sensing analysis software ENVI and a plug-in that is downloadable from NASA called CAT_ENVI (CRISM Analysis Toolkit). This project utilizes ArcGIS to analyze topographic data from Mars Orbiter Laser Altimeter (MOLA) onboard Mars Global Surveyor (MGS) and to create maps on top of this topography. Spectral data from CRISM and surface features from HiRISE will be investigated around NE Syrtis, centered at ~76.9°E, 16.7°N, Mars.

The results from this investigation include mineralogic maps and high resolution surface feature maps of NE Syrtis, specifically in the area that straddles the geologic contact between epochs. Descriptions of findings regarding geology and a comparison/contrast between Noachian and Hesperian geology are also incorporated.