GEOLOGIC MAPPING OF THE OLYMPUS MONS VOLCANO, MARS

We have completed a geologic map of the Olympus Mons (OM) volcano, Mars, using ArcGIS by ESRI. The final product of this project is to be a 1:1,000,000-scale map. The scientific questions upon which this project is based include understanding the volcanic development, including identification of volcanic unit source areas, and subsequent modification by structural, aeolian, and possibly glacial processes. To address our science questions we conducted morphology mapping at ~ 1:300,000 scale using the Context Camera (CTX) and High Resolution Stereo Camera (HRSC) image mosaic as our base data. This scale enables a distinction between sinuous rilles and leveed channels, which is fundamental for interpreting abundances among, and changes between, tube- and channel-forming eruptions. We also produced at 1:200,000 scale map of the caldera that provides additional detail of the summit region. We identified 34 units that are divided among Flank Units, Scarp and Apron Units, Plains Units, and Crater Materials. The Flank Units include 13 units, plus 7 caldera units. The basic morphological difference across the flank involves mottled and channeled units. The channel unit is typified by sub-parallel linear flows with levee structures. The mottled unit is hilly at the horizontal scale of 10s to 100s of meters. We did not delineate units that display the same morphology but appear to be the result of a different eruptive phase unless a unique source is inferred. Because a motivating question involves the identification of flank unit sources we subdivided channels and mottled units according to their apparent origin. These include Fan-sourced, Ridge-sourced, and Flank units (which can be traced to the caldera or have a source that is unclear). Fans and ridges are up to 100 m in height. Fans are delta-shaped whereas ridges are elongate, generally radial to the caldera. We identify a fan’s apex as a location point. We differentiate three scarp and three apron units. Our current efforts are focused on additional higher resolution mapping and data analysis related to the map product. These efforts include 1) the identification of lava tubes and their products on the flanks of OM, 2) the interactions between volcanic rocks and frozen volatiles on OM, and 3) the volcanic-tectonic development and constraints of the eruptive frequency of the volcano.