The Villany area, as a central part of the Tisza microcontinent/terrane along the
European margin of Tethys, was characterized by intense subsidence in the Early and
Middle Triassic, followed by a long interruption of subsidence in the Late Triassic
to Middle Jurassic. During the Middle-Late Jurassic transition, marine sedimentation
started with three distinct sedimentary episodes dated as Late Bathonian, Early Callovian,
and Middle-Late Callovian, respectively. The succession is terminated by a thick limestone
of Middle Oxfordian age. The sedimentary features, microfacies, and macroinvertebrate
associations of these four stratigraphic units are documented and illustrated. The
Middle to Late Jurassic sedimentary episodes of the Villany succession record an interplay
of local and global factors and paleogeographical changes. At the beginning, local
tectonic movements governed the main features of sedimentation, though the role of
eustasy was also essential. From the mid-Callovian onwards, global climatic, biotic,
and paleoceanographical changes controlled the nature and formation of the local carbonate
sediments. The Callovian stromatolites are attributed to the activity of sulphate-reducing
bacteria in a deep sublittoral, current-swept environment. Upwelling of eutrophic
Tethyan waters is recorded by the prevalence of the Bositra filament microfacies in
the Callovian. The long submarine hiatus at around the Callovian-Oxfordian transition
mirrors a serious restriction of the carbonate budget, due to sudden cooling and a
change in the oceanic current system (opening of a circumglobal Tethyan Passage),
and to a higher amount of dissolved CO2. In the Middle Oxfordian, the carbonate production
considerably increased in accordance with the sudden global warming.