A. Vengosh et al., THE ORIGIN OF MEDITERRANEAN INTERSTITIAL WATERS - RELICS OF ANCIENT MIOCENE BRINES - A REEVALUATION, Earth and planetary science letters, 121(3-4), 1994, pp. 613-627
Re-examination of interstitial waters from sixteen Mediterranean DSDP
sites reveals that the high salinity values of these waters (up to 350
g/l) do not reflect dissolution of underlying evaporites, but are rat
her related to Miocene evaporated sea water trapped in the sediments a
nd modified by diagenetic reactions and advection-diffusion. Only in t
wo shallow sites was the chemical composition of the interstitial wate
rs controlled by evaporite dissolution. The large variations in the ch
emistry of the interstitial waters among different sites suggests that
the Mediterranean was divided into separate sub-basins with different
chemical compositions. The composition of interstitial waters records
the history of the Mediterranean since Early Miocene as follows: (1)
salinization of the western Mediterranean during the Early and Middle
Miocene; (2) intrusion of low salinity water in the eastern basin duri
ng the Middle Miocene; (3) desiccation by evaporation of the Mediterra
nean during the Messinian (Late Miocene). Other processes, such as sul
phate reduction and dolomitization, took place along the sedimentary s
ection. The diffusion-advection processes in the interstitial water, i
n addition to smoothing the contrasts within vertical profiles of chem
ical concentrations, caused an upward shift in the liquid phase profil
e in respect to the solid phase, changed the vertical trend in the cas
e of an end-member which became exhausted, and brought about vertical
changes associated with the porosity structure.