[en] In 2015, a Phase 1 Geoscientific Desktop Preliminary Assessment was completed to assess whether the Blind River and Elliot Lake area contained general areas that have the potential to satisfy the geoscientific site evaluation factors outlined in NWMO's Adaptive Phased Management (APM) site selection process. The assessment was conducted using available geoscientific information and key geoscientific characteristics that could be realistically assessed at the desktop stage. The Phase 1 assessment revealed that the area contains at least three general areas that have the potential to satisfy NWMO's geoscientific site evaluation factors. In 2016, as part of Phase 2 of the preliminary geoscientific assessment of the area, NWMO initiated a series of initial geoscientific field studies in one of the three general potentially suitable areas identified during Phase 1 preliminary assessment. The objective of these initial field studies was to advance understanding of the geology of the general potentially suitable area, and assess whether it is possible to identify general Potential Repository Areas (PRAs). The initial Phase 2 geoscientific preliminary assessment included the following key activities: Acquisition and processing of high-resolution airborne geophysical (magnetic and gravity) data over one of the general potentially suitable areas identified in Phase 1 Geoscientific Desktop Preliminary Assessment; Detailed interpretation of the high-resolution geophysical (gravity and magnetic) data to better understand the bedrock geology (e.g. geological contacts, depth and extent of rock units, lithological and structural heterogeneity); Detailed interpretation of surficial and magnetic lineaments using the newly acquired high-resolution remote sensing and magnetic data to identify possible structural features such as fractures, shear zones and dykes; and Geological mapping to assess geologic characteristics, including lithology, structure, bedrock exposure and surface constraints. A total of six general Potential Repository Areas (PRAs) were identified in the area. These are general areas that encompass geoscientific potentially suitable areas. They are defined as relatively smaller areas that have the potential to meet NWMO geoscientific site evaluation factors, and have a sufficient volume of suitable rock that can fit one or more repository footprints (i.e. 6 km² or larger). The boundaries of the general PRAs are rough in nature and are not intended to be interpreted as geoscientific features or precise demarcations. General PRAs were identified based on the interpretation of available information to date, including high-resolution geophysical data, lineament interpretations, and geological mapping. Identified general PRAs in the area capture areas of lower density of integrated lineaments, with more favourable lithological and structural characteristics. While the identified general PRAs appear to have favourable geoscientific characteristics for hosting a deep geological repository, there remain uncertainties that would need to be addressed during subsequent stages of the site evaluation process through borehole drilling. Given the lack of subsurface information in the area, there is uncertainty on the structural and lithological character of the bedrock at depth. The presence of mafic dykes is also a source of uncertainty as some of the dykes encountered during the geological mapping lacked any significant geophysical contrast from the predominant granitic rock. (author)