The Development of Miocene Biohermal Bryozoan Limestones of Kazantip Cape (Crimea): A New Insight

The complex of modern physical methods for studying authigenic carbonate crusts in the Miocene bryozoan bioherms of the Kazantip Cape (Kerch Peninsula) has made it possible to reveal fossil biofilms and glycocalyx for the first time. These finds indicate that methanotrophic carbonate-precipitated bacteria during their activity strengthened brittle bryozoan skeletons. The presence of cavities in bioherms incrusted with goethite crusts, the presence of bitumen, pyrite, strontianite, barite, kutnagorite in the composition of carbonate crusts, and traces of the vital activity of methanotrophic bacteria are associated with the significant influence of near-bottom local gas–fluid seeps. This situation was determined by the occurrence of a discharge zone of rising gas–fluid flows in the Kazantip Cape area as a result of activation of mud volcanism, typical of the Neogene–Holocene interval of the Kerch–Taman Region.