A two‐step process for the reflooding of theMediterranean after theMessinianSalinityCrisis

Abstract

AbstractTheMessinianSalinityCrisis is well known to have resulted from a significant drop of theMediterranean sea level. Considering both onshore and offshore observations, the subsequent reflooding is generally thought to have been very sudden. We present here offshore seismic evidence from theGulf ofLions and re‐visited onshore data fromItaly andTurkey that lead to a new concept of a two‐step reflooding of theMediterraneanBasin after theMessinianSalinityCrisis. The refilling was first moderate and relatively slow accompanied by transgressive ravinement, and later on very rapid, preserving the subaerialMessinianErosionalSurface. The amplitude of these two successive rises of sea level has been estimated at ≤500 m for the first rise and 600–900 m for the second rise. Evaporites from the centralMediterranean basins appear to have been deposited principally at the beginning of the first step of reflooding. After the second step, which preceeded theZancleanGlobalStratotypeSection andPoint, successive connections with theParatethyanDacicBasin, then theAdriatic foredeep, and finally theEuxinianBasin occurred, as a consequence of the continued global rise in sea level. A complex morphology with sills and sub‐basins led to diachronous events such as the so‐called ‘LagoMare’.This study helps to distinguish events that were synchronous over the entireMediterranean realm, such as the two‐step reflooding, from those that were more local and diachronous. In addition, the shoreline that marks the transition between these two steps of reflooding in theProvenceBasin provides a remarkable palaeogeographical marker for subsidence studies.