The geochemical, metallogenetic, and mineralogical characteristics were studied in the hemipelagic sapropelic sediments from Site 378, boreholes 378 & 378A (Leg. 42A DSDP) in the north of Cretan basin revealing the existence of four lithologic units (I-IV). The upper 3 lithologic units contain detrital minerals that are predominantly consist of clays (principally illite & kaolinite), quartz and feldspars, whilst calcite is the most important authigenic mineral. The reducing environment rich in organic material most probably caused the production of mixed layers and authigenic sulfides in minor amounts. Most of the major and trace elements have a terrigenous origin that is related with the Rhodes-Karpathos-Crete drainage system. During the upper Pliocene and especially during the lower Pliocene (Unit III) the detritus input was enriched in mafic and ultramafic detritus whereas much of Si, V & Ba are biogenous and associated with the sapropelic organic material-rich sediments. Part of Mn especially in the upper part (Unit I) seems to be associated with a hydrothermal activity related with the submarine volcanic activity in S. Aegean during late Quaternary, whilst another proportion of Mn is related with the calcium carbonate-manganese phase which is quite common in sapropelic sediments. The basal Unit IV contains only a selenitic pure gypsum which is a product of the Messinian salinity crisis that resulted in the development of evaporites with a thick salt layer.

West: 25.0658 East: 25.0659 North: 35.5641 South: 35.5640

Expedition: 42

Site: 42-378

Provider: SEDIS Publication Catalogue

Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=1999-057305 (c.f. for more detailed metadata)

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