A new tectonic framework for the Flin Flon Belt in southeastern Reindeer Zone of the Trans-Hudson Orogen has emerged in recent years through four-dimensional studies (bedrock and subsurface mapping, seismic reflection profiling, U-Pb geochronology) associated with the NATMAP Shield Margin Project and Lithoprobe Trans-Hudson Orogen Transect. This special issue contains 10 papers covering a wide variety of topics related to the NATMAP Shield Margin Project.