The Sinap Formation of Central Anatolia, Turkey, contains fossiliferous sediments that represent the time period from about 15 Ma to about 2.5 Ma and documents an important interval of the terrestrial Neogene large land mammal evolution. Although the middle and late Miocene mammalian faunas from the Sinap Formation have been known for over 50 years, it is not until recently that a geological and chronological framework has emerged for these sediments. This framework is critical for producing a comprehensive view of the mammalian succession that can in turn be compared with results from localities in other regions.
The fossiliferous Miocene sediments of the Sinap Formation are located some 55km northwest of Ankara, Central Anatolia (Fig. 12.1). The Formation is named after Sinap Tepe, a prominent butte or ‘tepe’ in the area. The tectonic setting for this part of Central Anatolia is dominated by small fault-bounded basins (termed intermontane basins of various sizes: cf. Lüttig & Steffens, 1976; Erol, 1981) where folding events that are synchronous and pre- and postdate the Miocene have further complicated the structural geology of the area (Lunkka et al., 1998). These features are most likely related to the extensional neotectonics of Anatolia and the major North Anatolian transform fault (Angelier et al., 1981; Inci, 1991) that is located to the north of this region.
The Miocene sediments in the study area rest unconformably upon suites of pre-Miocene tectono-sedimentary melange and forearc basin-fill rocks that are related to the closure of the Neo-Tethyan Ocean (şengör & Ylimaz, 1981; Koçyiğit, 1991; see Fig. 12.1). Terrestrial Miocene strata consists mainly of volcaniclastic sediments that are relatively well-exposed along the flanks of several prominent buttes in the general region around the town of Kazan (see Fig. 12.1).