Planktonic Foraminifera Response to Sudden GlobalWarming in Late Maastrichtian, a Case Studyfrom Ziyarat-Kola, Central Alborz, Iran

An abrupt global warming event has been recorded in many parts of the worldin sediments of latest maastrichtian age between 65.45-65.10 ma. this warmevent was documented here at a section near ziyarat-kola in central alborz basedon analysis of planktonic foraminifera. an unusual abundance of normally largesizespecies such as globotruncana arca, globigerinelloides subcarinatus,pseudoguembelina hariaensis and rugoglobigerina rugosa in small-size fraction(63-150) was recorded. a similar trend of increasing in relative abundance ofsome opportunist species such as guembelitria spp. was also recorded. at thesame time, laeviheterohelix dentata a long ranging dominant species, decreasesconsiderably reflecting a high stress environmental condition as warming.palynological studies show an increase in fungal spore and in thermophilic speciesconfirming the result gained from foraminiferal analysis.