Tephrostratigraphy and tephrochronology of lakes Ohrid and Prespa, Balkans

[摘要] Four cores from Balkans lakes Ohrid and Prespa were examined for recognitionof tephra layers and cryptotephras, and the results presented along with thereview of data from other two already published cores from Lake Ohrid. Thesix cores provide a previously unrealised tephrostratigraphic framework ofthe two lakes, and provide a new tephrostratigraphic profile (composite) forthe Balkans, which spans from the end of the Middle Pleistocene to the AD472. A total of 12 tephra layers and cryptotephras were recognised in thecores. One is of Middle Pleistocene age (131 ka) and correlated to themarine tephra layer P-11 from Pantelleria Island. Eight volcanic layers areUpper Pleistocene in age, and encompass the period between ca. 107 ka andca. 31 ka. This interval contains some of the main regional volcanic markersof the central Mediterranean area, including X-6, X-5, Y-5 and Y-3 tephralayers. The other layers of this interval have been related to the marinetephra layers C20, Y-6 and C10, while one was for the first time recognisedin distal areas and correlated to the Taurano eruption of probable Vesuvianorigin. Three cryptotephras were of Holocene age. Two of which have beencorrelated to Mercato and AD 472 eruptions of Somma-Vesuvius, while thethird has been correlated to the FL eruption from Mount Etna. Theserecognitions provide a link of the Ohrid and Prespa lacustrine successionsto other archives of the central Mediterranean area, like south Adriatic,Ionian, and south Tyrrhenian seas, lakes of southern Italy (Lago Grande diMonticchio, Pantano di San Gregorio Magno and Lago di Pergusa) and Balkans(Lake Shkodra).

[学科分类] 地球化学与岩石