Ocean. After Hettangian drowning and Sinemurian-Pliensbachian extensional tectonics and subsidence, along with pelagic sedimentation and submarine topography, a pronounced horst developed over the local sea, with a depth on the Pliensbachian-Toarcian Basin of 600 m. The environment of the Formation was linked to 2 settings: a series o pelagic basind, including the Zala Basin and the own Úrkút and Eplieny Basins, related to open marine conditions where bioturbation is scarce, but there is a great amount of planktonic organisms, associated with a suboxic to anoxic conditions. Radiolarians, sponge spicules, crinoid ossicles, bivalves, gastropods, ammonites and fish were recovered as the main local biota, deposited on a 20–40 m basinal ore sequence. The Other deposits come from the near emerged lands, that include the Gerecse Hills, Vértes Hills and the Bakony Hills, whose biota has been recovered on the formation by palynological analysis and fossil wood. More recent studies support the lack of any igneous event during Pliensbachian and Toarcian times in the Úrkút Basin. The Smectite formation lacks igneous rocks, tuffs, or volcanic glasses. Although, it can be due to changes in the fluctuation on the basin. Observed Mn veins and their above-proposed formation mechanism do not eliminate the possibility of tectonically formed Neptunian dikes elsewhere in the basin, which could well fit in the local, general tectonic environment observed, for instance in Eplény. In this setting volcanism was the main local event, where eroded near basaltic sequences provided a metallic source for the ore, being channeled by suboxic waters to the Úrkút Basin. The local tectonic activity created fractures and deep faults and there was a development of endogenic thermal effects, such as degassing and the release of solutions, along with the mixing of syngenetic ash falls that deposited Fe into the carbonate rocks. The fine Volcanic material was altered on the Marine sediments. The local hydrothermal emanations in the deep fault zones, where bacterial activity caused the precipitation of large amounts of metal ions in the form of very fine-grained oxyhydroxides. Meanwhile, the accumulation of dead bacteria created a mass of very reactive organic matter. Under aerobic conditions, the action of the microbial oxidation led to the local accumulation of Mn oxides that ended being Ca-rhodochrosite, and supported Celadonite formation by mixing of geological fluids with seawater. It has been calculated 563 years for the duration of ore local formation based on an estimated 3 weeks for a