Abstract
Selected aspects of the geochemistry of 395 meta-igneous rocks from the polymetamorphic Ordenes Complex are described in an examination of recently proposed ophiolite models for their genesis. The metabasites are sub-alkaline, tholeiitic and geochemically indistinguishable from mafic rocks of oceanic suites and ophiolites. The geochemistry is consistent with a proposed division of the protoliths into gabbros, including ferrogabbros, and submarine volcanic rocks. The metamorphosed equivalents of highly sodic acidic igneous rocks also occur. These data provide strong support for the ophiolite model. High Ti fractionation trends suggest that ophiolite generation occurred either at a mid-ocean ridge or in a partially evolved back-arc basin.