Abstract
Recent concerns over naturally occuring earthquakes, precipitated by the shale gas industry reactivating faults and the potential impact on surface structures and shallow aquifers have prompted this study to catalogue the location, type, current stress state and proximity to the surface of major Cambrian to early Ordovician faults in the St. Lawrence Lowlands of Québec.
A considerable amount of geophysical data has been collected in the St. Lawrence Lowlands of Québec over the last 30 years allowing for accurate mapping of the fault network within the Cambro-Ordovician deposits, the area being targeted for shale gas development.
Integration of modern 2-D seismic, high resolution aeromagnetic surveys, lineament analysis of surface topography and recent geophysical well logs have resulted in detailed maps of the faults affecting the autochthonous strata of the St. Lawrence Lowlands.
After correlating these maps to present day in-situ stress maps and earthquake data it has been determined that hydraulic fracturing of the Utica shale in the south shore region of the St. Lawrence Lowlands is highly unlikely to reactivate near surface faults affecting shallow aquifers or surface structures.
