It would be useful to define precisely at the outset the term ophiolite, for it has had various meanings over the course of time. Although, used by Brongniart, Fouquet, Michel-Levy and Dana, one should start with the concept introduced by Steinmann in 1927 to cover the association of peridotites, gabbroes, diabases and spillites, the existence of a link. between these different rock types has led to the word ophiolite being used more as a descriptive than a genetic term. The Penrose Conference of 1972 proposed a more restrictive definition, which, unfortunately, has not been generally accepted.