GEOSPATIAL ANALYSIS OF LUNAR PYROCLASTIC DEPOSITS WITH FLOOR-FRACTURED CRATERS AND IMPLICATIONS OF SOURCE MAGMATIC REGIONS

The erupted juvenile volcanic materials in lunar pyroclastic deposits may be the best samples from the lunar interior from which to extract compositional clues about the origin of the Moon and the environment of lunar volcanism. Characterization of the location and distribution of iron-rich glass in pyroclastic material is important for studies such as lunar in situ resource utilization and oxygen production, both urgent topics for lunar exploration. We outline a statistical study of the correlation of the location of pyroclastic materials on the Moon with floor-fractured craters (FFCs) in constraining magmatic source regions for the pyroclastic eruptions. Using a global rendering of the lunar surface (Lunar Reconnaissance Orbiter Camera), a compiled database of pyroclastic deposits, and a database of FFCs (Jozwiak et al. 2012), we spatially describe the frequency of pyroclastic deposits within FFCs, near FFCs (with significance), and not associated with FFCs (e.g. in lunar maria or within unmodified craters). We modify the Jozwiak et al. (2012) data by changing from points that represent crater centers to polygons representing the crater rims. Then using geographic information system (GIS) spatial analyses we determine whether a deposit is located within, near (within one crater radius), or not associated with a FFC (i.e. not near or within a FFC). The nearness of a deposit to an FFC is determined by creating a buffer around each polygon with a width of one crater radius. Each deposit not within an FFC is assigned to a “nearest neighbor” crater and then assigned as “within buffer” or “not within buffer”. Additionally, local indicators of spatial association (LISA) statistics will be calculated for each crater to model the level of spatial autocorrelation between deposits and craters, which can identify local patterns within the study area. This analysis allows us to relate proximity of pyroclastic deposits to floor fractures that represent local crustal deformation, to assess the frequency of surface eruption of those deposits along such pathways, and to evaluate these data in light of crustal thickness models to determine more effectively the magmatic source regions for lunar pyroclastic deposits and potentially permit prediction of deposit composition (via spatial analysis) and distribution (via ballistic modeling).