(A) Representative arsenopyrite (Asp) and wolframite (Wolf) bearing quartz vein from the Costillon vein (outcrop A in Fig. 3) showing the structural features and the relationships with the paragneiss host-rock and the leucogranitic dykes. (B) Detail of drag folds developed in the country-rock paragneiss along the contact between the arsenopyrite (Asp) and wolframite (Wolf) bearing quartz veins and leucogranitic dyke. La Borie vein (outcrops B in Fig. 3).