The paper presents preliminary observations on the development and depositional features of the Tylav Limestone, which is the oldest coccolithic limestone horizon in the Oligocene of the Carpathians. The Tylavian limestones occur as thin intercalations in menilithic rocks. A characteristic feature of these limestones is a special type of lamination. The thin laminae are arranged as separate successions. These sequences are suitable for long-range comparison of the laminated limestones of Tylawa in different tectonic subdivisions of the Carpathians. Features such as erosional discontinuities, plastically deformed plates, dissolution structures, and sediments between plates, such as thin interbeds of silt, clay, or unlaminated limestone, may hinder detailed correlation of the laminae sequences. Observations on the distribution and development of the Tylavian limestones seem to confirm the presence of an Early Oligocene event in the Carpathian Basin, which contributed to the deposition of Tylavian limestones over a wide area.
