One river of this name is found in Ontario and is the namesake of a series 
One river of this name is found in Ontario and is the namesake of a series of Precambrian rocks that are similar to the Knife Lake Series and adjacent to the Keewatin Series. Tributaries of another river of this name form in the Morvan highlands, an extension of Massif Central. The "mascaret" is the phenomenon of tidal bore between the mouth of this river and the English Channel. Cities that lie on this river include Rouen and Troyes. It has two natural islands, Ile Saint-Louis and Ile de la Cite, both located where it passes through the largest city on its banks. For 10 points, identify this river which cuts through Paris.
One river of this name is found in Ontario and is the namesake of a series of Precambrian rocks that are similar to the Knife Lake Series and adjacent to the Keewatin Series.
Seine River