Planktonic Foraminifera Response to Sudden Global Warming in Late Maastrichtian, a Case Study from Ziyarat-Kola, Central Alborz, Iran

Author
M. Asgharian Rostami
Abstract
An abrupt global warming event has been recorded in many parts of the world in sediments of Latest Maastrichtian age between 65.45-65.10 Ma. This warm event was documented here at a section near Ziyarat-kola in Central Alborz based on analysis of planktonic foraminifera. An unusual abundance of normally large-size species 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 of some opportunist species such as Guembelitria spp. was also recorded. At the same time, Laeviheterohelix dentata a long ranging dominant species, decreases considerably reflecting a high stress environmental condition as warming. Palynological studies show an increase in fungal spore and in thermophilic species confirming the result gained from foraminiferal analysis.
Keywords
Central Alborz
Global warming
Iran
Late Maastrichtian
Planktonic Foraminifera