Ultramafic rocks were recovered from the lower parts of holes at four sites (567, 566, 569, 570) drilled on Leg 84. These sites are on the landward slope of the Middle America Trench off Guatemala. Harzburgites, cumulative texture peridotites, gabbros, dolerites, and amphibolite facies rocks were recognized by pétrologie and geochemical analysis (Xray fluorescence, microprobe). Some of these rocks belong to an ophiolitic sequence. They form the basement of the landward slope of the Guatemala...