On the hydronym toron-toró (source, fountain) and its southern border in Catalonia

Catalan, like Occitan, has two very similar lexical forms but whose meaning is quite distinct. Thus, on the one hand, in archaic Catalan we find toron-toró (source, fountain) coinciding with teron, toron (id.) in present-day Occitan and, on the other, we find turó (hill) in modern Catalan modern coinciding with turon (id.) in Occitan. Given that the limits of this hydronym are uncertain in Occitania, this article seeks to define the limits of its southern extent in Catalonia.