[en] In July 2014, the Municipality of Central Huron (herein ^the Municipality⁾ expressed interest in continuing to learn more about the Nuclear Waste Management Organization (NWMO) nine-step site selection process (NWMO, 2010), and requested that a preliminary assessment be conducted to assess potential suitability of the Municipality for safely hosting a deep geological repository (Step 3). This request followed the successful completion of an initial screening conducted during Step 2 of the site selection process. The preliminary assessment is a multidisciplinary study integrating both technical and community well being studies, including geoscientific suitability, engineering, transportation, environment and safety, as well as social, economic and cultural considerations. The findings of the overall preliminary assessment of the Municipality are reported in the integrated report (NWMO, 2015). The objective of the Geoscientific Desktop Preliminary Assessment is to determine whether the Municipality contains general areas that have the potential to meet NWMO's geoscientific site evaluation factors. The purpose of the geophysical interpretation was to provide additional information of the geological features associated with both the Paleozoic sedimentary units and the underlying crystalline rocks of the Precambrian basement within the Municipality and its immediate periphery referred to as the Central Huron area. Available geophysical data were assessed to determine potential lithological variations within the Precambrian basement, and identify broad lithological domains. An attempt was made using gravity data in the Central Huron area to identify features within the Precambrian basement, as well as potential features such as pinnacle reef structures and the presence of thick salt occurrence within the overlying Paleozoic sedimentary sequence. The geophysical data covering the Municipality vary from low to high data set resolution. Lower resolution magnetic, gravity and radiometric data were obtained from the Geological Survey of Canada (GSC) for the entire Central Huron area. These were supplemented by moderate resolution magnetic and high-resolution gravity multi-client data sets acquired from industry sources. No electromagnetic data were available for the Municipality or Central Huron area. In this study, available magnetic data were used to assess the lithological variations within the Precambrian basement, since the overlying sediments are magnetically transparent. The magnetics identified two broad lithological domains indicating variability in rock type or metamorphic grade. Magnetics and gravity data also identified ductile features in the Precambrian basement that are interpreted as being associated with the internal fabric of the crystalline basement and likely include tectonic foliation or gneissosity. The Bouguer gravity data were assessed in order to focus on identifying features within the overlying Paleozoic sedimentary sequence such as lateral variations in rock density associated with lateral changes in depositional environments, such as pinnacle reefs and salt units. This assessment suggests that there is some correspondence of the Bouguer gravity data with pinnacle reefs, but no discernable correspondence of gravity data with salt unit occurrence in the Central Huron area. Radiometric results show a strong correlation with the distribution of the mapped Quaternary deposits, as well as impacts from varying amounts of vegetation cover, soil moisture, and surface water. Radon risks throughout the Central Huron area are considered to be low. (author)