Varentsov(2002)による〔『Genesis of the Eastern Paratethys manganese ore giants: impact of events at the Eocene/Oligocene boundary』(65p)から〕

『Eastern Paratethysマンガン巨大鉱床の成因:始新世/漸新世境界における事変の影響』

The giant Mn ore deposits of the Paratethys are located on the slopes and/or margins of deep basins. The Eocene ocean and associated basins were strongly influenced by large-scale submarine hydrothermal activity which supplied prodigious amounts of Ca, CO2, SiO2, Mn, and other components to the oceans. This caused a substantial shift in seawater composition and resulted in the deposition of carbonates as well huge amounts of Mn. The giant Mn ore deposits of the Eastern Paratethys were formed as a consequence of the Early Oligocene global transgression in shelf environments of marginal and epicontinental seas, frequently with anoxic regime of the bottom water.

Keywords: Mn ore giant deposits; Eastern Paratethys; Ocean hydrothermal activity; Black shale basins; Early Oligocene, Global transgression; Recycling; Diagenesis』

1. Introduction (formulation of the problem)
2. Materials and methods
3. Manganese ore basins
4. Paleostructure-paleogeographic features of the Mn ore basins
5. Geochemical features of the World Ocean at the Eocene/Oligocene boundary
6. The role of submarine hydrothermal activity in the geochemistry of sedimentation in the World Ocean
7. Geochemical effects of submarine hydrothermal activity as exemplified by Ca, CO2, and Mn
8. Features of sedimentation, climate changes, and eustatic oscillations of the World Ocean level at the Eocene/Oligocene boundary
9. Mn ore formation in the basins of the Eastern Paratethys
10. Conclusions