Abstract: The beginning of Neogene terrestrial sedimentation in the northeastern coastal part of the Çeşme Peninsulais represented by the Şifne formation, which its lowermost part is not exposed. The age of successionevaluated as Early Miocene stratigraphically and its uppermost observable part consists of lacustrinelimestone bearing fresh water algae. The ignimbrite flows, early products of Armağandağı volcanism,stopped and ended the sedimentation of Şifne formation.The Armağandağı volcanics represents the late Early Miocene-early Middle Miocene calcalkalinevolcanism in the Çeşme Peninsula. The tongues of the volcanism in the study area are mainly composedof volcaniclastics. The volcaniclastic assemblage comprises felsic ignimbrites at the lower part namelyAlaçatı tuff, and andesitic ignimbrite, blocky ash flow deposits and lahars of Reisdere volcaniclastics atthe upper part. Alaçatı tuff is located between Şifne formation and Reisdere volcaniclastics. The Zeytineliformation represents the lavas of the Armağandere group.The Ildır formation overlies the pre-Neogene basement rocks with an angular unconformity and laterallygrades in the upper part of the Armağandağı volcanics. They represent the early Middle Miocenesedimentation and calcalkaline volcanism. The lacustrine Ildır formation is composed of mudstonesandstone alternation in the lower part and clayey limestone at the upper part, and comprises theBelentepe member deposited in a fan-delta environment in the lower part. A synsedimentary lava level inthe Belentepe member dated as 14.6±0.6 Ma by K/Ar method. This lava level is a tongue of the Zeytineliformation, and its age shows that the activity of Armağandağı volcanism continued in the early MiddleMiocene.