[1] Univ Utrecht, Fac Geosci, Dept Earth Sci, Lab Palynol & Paleobot, NL-3584 CD Utrecht, Netherlands
[2] Russian Acad Sci, Inst Geol, Moscow 109017, Russia
[3] NIOZ Royal Netherlands Inst Sea Res, NL-1790 AB Den Burg, Texel, Netherlands
[4] Univ Utrecht, Fac Geosci, Dept Earth Sci, NL-3584 CD Utrecht, Netherlands
[5] Russian Acad Sci, Siberian Branch, Inst Petr Geol & Geophys, Novosibirsk 630090, Russia