Présence des basaltes porphyriques dans les zones de fracture de la dorsale Est-Pacifique.

The volcanics dredged From the East Pacific Rise are almost aphyric basalts. Here we describe phyric lavas collected from two fracture zones (Garret F.Z. at 14°s and Quebrada F.Z. at 4°s). An orher exception is known in Siquieros F.Z. at 9°N. The occurrence of such phyric basalts associated with East Pacific fracture zones needs therefore to be discussed. [NOT CONTROLLED OCR]