GIS-Based Analysis of Secondary Craters as Stratigraphic Markers, Mars

U.S. Geological Survey

Analyzing size-frequency distributions of impact craters is the fundamental technique used for assessing the relative age of surfaces on planetary bodies beyond Earth. The basic idea is that old surfaces have more craters than younger surfaces due to longer exposures to interplanetary debris. Relatively small craters are the most abundant, so they can be the most useful for dating surfaces, but only if they are caused by primary impacts. However, recent results support the theory that secondary impacts dominate the number of small craters.

This map presents preliminary results in utilizing secondary craters, specifically those grouped into large, high-crater-density clusters called Large Crater Clusters (LCCs), as a means to aid in the dating of surfaces on Mars. A GIS-based program was developed to backtrack LCCs to their primary craters. The program models ejection-trajectory-impact scenarios by using crater points derived from satellite imagery. The stars on the map indicate the circum-Utopia Planitia regions of Mars with most trajectory intersections where potential primary craters may exist.

Courtesy of U.S. Geological Survey, Astrogeology Science Center.

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