According to the detailed structural analysis, aluminosilicate-bearing veins are formed between the D3 and D4 deformation phases. They cut the main schistosity (S2-S3a) and are folded by the deformation phase D4, linked to the Larecc's anticline. Additionally, thermometry by oxygen isotopes on quartz and aluminosilicates pairs confirms that the formation of those minerals tooks place at maximum of temperature, between D3 and D4. The formation of those veins is so contemporaneous with the peak of metamorphism.