Discovery of an anoxic basin within the Strabo Trench, eastern Mediterranean

Interstitial water studies of Late Quaternary eastern Mediterranean sediments with emphasis on early diagenetic reactions and evaporitic salt influences

“…Messinian diapirs in the vicinity of coring site T83-7 are reported by several workers ( Leit6 and Mascle, 1982;Le Pichon et al, 1979;Jongsma et al, 1983;Peters and Huson, 1985) and it seems reasonable to attribute the features in core T83-7 to salt influences. How then can the lack of Na enrichment with depth be explained?…”

“…The uppermost 3 cm of the piston core sediment is brown colored, whereas the rest of the sediment has a greyish-green color similar to the sediment color of core T83-46. This observation in combination with the C1 profile ( Fig.8A) was interpreted as evidence for the presence of anoxic hypersaline conditions in the Kretheus Basin up until very recently (Jongsma et al, 1983;De Lange and Ten Haven, 1983). Preliminary diffusion calculations revealed the turnover time to be ca.…”

“…Although several hypotheses have been proposed to explain the occurrence and formation of these sapropels, it is generally accepted that they are formed in anoxic environments (see Ten Haven et al, this volume, for a review). Recently such conditions were discovered in the Tyro Basin (Jongsma et al, 1983) and in the Bannock Basin (Scientific staff of cruise Bannock 1984Bannock -12, 1985 in the Eastern Mediterranean. The NHa concentration in interstitial waters from the Tyro Basin increases from 1000 up to 3000 ~mol l-1 at 4 m depth ; see also Fig.6A) and the pH of the interstitial waters is ca.7 (Fig.6A).…”

“…Core T83-46 This core, collected in the anoxic hypersaline Tyro Basin, is unique for the Mediterranean (Jongsma et al, 1983). The brine is thought to be derived from dissolution of outcropping Messinian salt (Ten Haven et al, 1985;Jongsma, this volume).…”

“…Two similar anoxic hypersaline basins are known; viz. Tyro Basin (Jongsma et al, 1983) and Bannock Basin (Scientific Staff of cruise Bannock 1984Bannock -12, 1985. Preliminary interstitial water analyses of sediments from the Kretheus Basin, adjacent to the Tyro Basin, suggested that hypersaline and anoxic conditions existed in this basin up to very recently .…”