Abstract: The ophiolitic rocks, which were emplaced on the continental margin in the Aladağ region of Tauridsduring Maestrichtian, make up a sequence consisting of three units that are the ophiolitic melange at the base, themetamorphic slice over it, and the peridotite nappe at the top. One of the important subunits within the sequence isthe diabase dykes which transect the metamorphie slice and the peridotite nappe.The diabase dykes generally trend NE-SW and dip almost vertically. Their thicknesses range between 0.5-10 niThe dykes do not transect the ophiolitic melange and the Paleozoic and Mesozoic limestones underlying the melange.No dykes transecting metamorphics and peridotites together are observed.The diabase dykes exhibit crystal sizes varying from fine to medium, starting from cooling borders towards center. Dominant minerals are labradorite, augite, and hornblende. The dykes are subalkaline and tkoleiitic, composition isclose to that of abyssal tholeiites.The intrusion had occurred before the emplacement of the ophiolitic sequence, and most probably in an oceanicenvironment, since diabase dykes transect only the uppermost two unîts and they are close to abyssal tholeiites incomposition.