| Measurementsfrom the Cassiniorbiterrevealed that Saturn’s moon, Enceladuscontains a hydrothermally-active liquidwater oceanunderneath its icy shell. This thesiscontributes to understanding the microbial habitability potential of Enceladus by evaluating the major controls on the chemical exchange between submarine rocks, hydrothermal fluids, and seawater at the Lōʻihi seamount. Lōʻihi is a compelling hydrothermal analog system for Enceladus due to its environmental conditions (temperature, pressure), host rock type (ultramafic/mafic silicate),and geologicsetting (hotspot). We utilized petrographic and scanning electron microscopy paired with major and trace element spectrometryto quantify distinct chemical populations of minerals, make qualitive observations of mineralspatial distribution, and compare the relative bulk geochemical abundance of the exterior to interior within samplesfrom across Lōʻihi. Theseanalyses indicate thatLōʻihi hasa spatially and temporally complex hydrothermal system with large changes in composition, and therefore potential habitability, over centimeter and larger scales. Key Words: Habitability, Hydrothermal, Basalt, Alteration, LōʻihiSeamount, Enceladus, Analog |