Conference:
12th Congress RCMNS, 6-11 September, Vienna, Austria.
Author:
Speranta-Maria Popescu.
Abstract:
High-resolution palynology was performed on five well-dated Zanclean sections from southeastern Europe such as Lupoaia in the Dacic Basin (SW Romania) (Popescu et al., in press) and DSDP Site 380A (Black Sea) witch also includes Messinian sediments (Popescu, in press).
Pollen flora show how these regions was relatively protected from extinctions, which occurred in Europe during the Late Pliocene and the Quaternary because of glacial phases. A noticeable effect of Asian monsoon has probably encouraged persistence in this area of some thermophilous species (Popescu, 2001, Suc et al., 2004).
Altitudinal forest belts have been reconstructed on the southern Carpathians. Paleo-Danube delta was thick in swamps inhabited by Taxodiaceae forests and marshes occupied by grasses (Cyperaceae) as today in Florida and Mississippi delta. Descents of altitudinal gymnosperms belts are related to “coolings” with respect to eccentricity 100ky cycles (Popescu, 2002). On contrary, warmer phases forced development of thermophilous trees and lignite deposition. Asian monsoon probably controlled opposing development of swamps and marches with respect to the precession cycles, that enable a comparison with Mediterranean sapropels (Popescu et al., in press). Precession minima (monsoon enhancement) advantaged marshes, which require more humidity than swamps. This suggests the establishment of a longitudinal gradient over the Mediterranean region. As today, a strong contrast separated vegetation features between Dacic and Pontic realms. In the latter, thermic cycles forced competition between thermophilous trees and Artemisia steppes in the early development of which announces their forthcoming development over the whole Mediterranean region in relation with earliest glacial (2.6 Ma).
Such high-resolution pollen records provide a very detailed climatic record (similar to d18O curve) with respect to global climatic changes between 6 and 3.8 Ma. So, weak variations in temperature and humidity occurring during the warm Pliocene will more understood as well as their effects on the vegetation. The European Pliocene climatostratigraphy is confirmed and Central Paratethys deposits receive for the first time a reliable cyclostratigraphy. Relationships will be easier with the reference Mediterranean marine sections (Popescu, 2001, 2002).
Consequences of the Mediterranean Sea desiccation (Messinian Salinity Crisis) over the Black sea are evidenced: they concern both coastal vegetation and dinoflagellate assemblages. A new idea of Mediterranean-sea – Central Paratethys relationships is proposed.