The Cauterets-Panticosa granite complex, including Panticosa, West-Cauterets and East-Cauterets
plutons, crops out in the Axial Zone of the Pyrenees, and generated a continuous metamorphic zone. In
the Tena Valley, Panticosa and West-Cauterets plutons are intrusive in a Devonian metasedimentary series
that show a low regional metamorphism. In the thermal aureole, limestones are transformed into marbles
and pelitic rocks into hornfelses. The most common minerals in metapelitic rocks are biotite + andalusite
± muscovite ± cordierite ± almandine. In this region the thermal aureole cartography is based on the
presence of andalusite.
In this work, we describe for first time the presence of chloritoid. The chloritoid is overprinting the rock
fabric of the fine-grain schists. The microprobe analysis of chloritoid resulted in high contents of FeO and
low contents of MgO and MnO. Finally, the geological implications of the chloritoid determination up to
1.5 km from the cartographic aureole were discussed