The Izmir-Ankara-Erzincan zone in Turkey is part of the Anatolide belt. In NW Anatolia, near Kutahya, the ophiolitic rocks within the Izmir-Ankara-Erzincan suture zone have a tholeiitic character and oceanic back-arc chemistry. Amphibolites form a metamorphic sole to part of the ophiolite in the Kutahya region and yield an Ar-40/Ar-39 age of 93 +/- 2 Ma, interpreted to record high-grade metamorphism and intraoceanic thrusting of pre-existing ocean crust. Gabbros and dykes yield Ar-40/Ar-39 ages of 94 +/- 13 Ma and 48 +/- 12 Ma. The first is suggested to be the ophiolite formation age, and the second a regional metamorphic event, The ophiolitic rocks of the Kutahya region are composite and record several events in the evolution of a Neotethyan seaway situated in north-central Anatolia and farther east. They are interpreted to have formed in a small ocean basin marginal to the subducting Izmir-Ankara-Erzincan ocean. The Kutahya ophiolites of the Anatolide belt are similar in age to the Tauride ophiolites, and the sub-ophiolite metamorphic rocks and dykes in the ultramafic parts of the ophiolites in the Anatolide-Tauride Block formed at the same intraoceanic subduction zone within the same Neotethyan ocean.