Mio-Pliocene phonolite dome (Mégal volcanos, Emblavez Tertiary basin).
Fumarolitic deposition (350-200°C) products in fracture plans and prismation of the dome.
Quarry near Le Pertuis village, along road D 35.
Ref.:
Bull. Soc. Franç. Minéralo. Cristallo. , 1974, 97, p. 494.