Upper Cretaceous lythostratigraphy in the West Srednogorie. Part 1.

In this paper a new lithostratigraphic scheme of the Upper Cretaceous rocks in the West Srednogorie is proposed. In the present Part 1 seven new formal lithostratigraphic units in the Melove, Lyubash and Sofia tectonic Units are introduced: Paramun, Izvor, Rosoman, Melove, Golesh and Kosharevo Formations, and Kreshna Member of the Izvor Formation. The lowermost Paramun Formation (Lower-Middle Turonian), known as "coal-bearing formation", is a transgessive facies of light-gray to rusty-brown conglomerates, sandstones and siltstones with clay, marl and coal interbeds. It is up to 150-200 m thick and crops out as a thin strip at the base of the Upper Cretaceous sections in all of the West Srednogorie tectonic units. The overlying Izvor Formation (Middle Turonian-Coniacian) in Lyubash and Melove Units consists of more than 230 m strong marls, limestone beds and carbonate concretions with 90 m soft marls in the upper part of the unit north of Lyalintsi village, defined as Kreshna Member. The Golesh Formation (Coniacian-Lower Santonian) is a lateral analogue of the Izvor and Melove Formations, composed of about 180 m weakly cemented sandstones and soft clayey-sandy marls between Izvor and Melove Formations in Melove Unit. The Melove Formation (Coniacian-Santonian) is composed of up to 250 m thinbedded carbonate turbidites cropping out in Melove, Lyubash and Sofia Units. The Rossoman Formation (Santonian-Lower Campanian) is composed of more than 750 m alternating volcanic-sedimentary rocks with argillite-marl-limestone interbeds widespread in Sofia Unit. The Kosharevo Formation (Lower Campanian) is composed of more than 92 m marls, limestones, sandstones and polygenetic conglomerates. [ABSTRACT FROM AUTHOR]