Ophiolites in Earth History



I began my undergraduate studies in geology in 1974, shortly after the release of the now famous “Anonymous” report on the first Penrose Conference on Ophiolites (Geotimes, 1972). My early geology courses were filled with information on the nature of the seafloor, with details supplied largely from on-land studies of ophiolites. Pillow basalts and sheeted dike complexes, gabbros, peridotites, and cherts—all of these caught my attention and seemed so elegantly explained by formation at oceanic spreading centers.

Over the next couple of decades, I simply assumed that ophiolites were direct analogues for material produced at mid-ocean ridges, and I missed the nuances of the ongoing debate about whether or not ophiolites really are representative of this tectonic setting.