| Popis: |
A large consensus has been reached on a three-stage evolutionary model of the Messinian salinity crisis (MSC), each of them characterized by a peculiar association of evaporitic deposits, which record changes in the Mediterranean basin hydrology. However, a general agreement on what actually happened during the MSC, and particularly in the deepest settings of the Mediterranean basin, is still far from being obtained and several scenarios of the crisis have been proposed, with different implications for hydrocarbon exploration. The current MSC paradigm - the “shallow-water deep-basin” model - implying high-amplitude sea-level oscillations (>1500 m) of the Mediterranean up to its desiccation, is often considered as a fact. Actually, the different MSC scenarios so far proposed should be considered as theories needing to be proved. In recent times the desiccation theory has been questioned on its main arguments. We suggest an alternative, deep-water, non-desiccated scenario implying the permanence of a large water body in the Mediterranean throughout the whole MSC with strongly reduced Atlantic connections. The model has important implications for the exploration of the deep Mediterranean and the assessment of its hydrocarbon systems. In particular, its impact for a better definition of source rock generation and distribution, as well as of the magnitude of water unloading processes and their effects on hydrocarbon accumulations, should be carefully considered and evaluated. |
