| The
northward plate tectonic motion of the African/Arabian continent during
the Neogene (24-0 Myrs ago) has led to the closure of the Tethys Ocean.
The Alpine- Himalayan orogenic barrier separated this ocean into the Mediterranean
domain and the so-called “Paratethys” domain; a large endemic water mass
that extended from Austria to Iran, with the Black Sea and Caspian Sea
as actual remnants. Both domains have experienced dramatic paleoenvironmental
(and tectonics) changes during the Neogene, examplified by the desiccation
and reflooding of the Mediterranean during the Messinian Salinity Crisis
(6-5.3 Myrs ago) and the desiccation and reflooding of the Black Sea during
an event that might be related to the biblical flood of Noah (~8 kyrs ago).
The semi-enclosed land-locked
configuration of the Mediterranean region has appeared to be extremely
sensitive to record changes in paleoclimate and paleoenvironment and integrated
stratigraphic studies have revealed that the sedimentary record accurately
reflects astronomically induced changes in solar insolation. This has allowed
the construction of very detailed astronomically tuned geological polarity
time scales, which at present underlie most modern paleoclimatic, paleoceanographic
and paleogeobiologic research efforts.
Fieldwork
in Taman peninsula (Russia)
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In contrast,
the time scale for the Paratethys domain is highly equivocal and controversial
ages exist for many events and geological stage boundaries.
The small marine opening
through the Bosporus did not exist during large parts of the Neogene. The
key question that hampers a full understanding of the paleoclimatological
evolution of Eurasia during that time period thus relates to the closure
and opening of the marine connection(s) between Mediterranean and Paratethys,
and is at present far from understood.
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'Fieldwork'
in Loosdrecht (Holland)
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