[1] A high-resolution record of exceptionally well preserved calcareous nannofossil assemblages from Tanzania is marked by two key transitions closely related to the climatic events of the Eocene-Oligocene transition (EOT). The first transition, at 34.0 Ma, precedes the first positive shift in dO and coincides with a distinct interval of very low nannofossil abundance and a cooling in sea surfa...

Calcareous nannofossil assemblages recovered from a long, continuous section have been described from the Sarayan region in Lut Block in east Iran. The marine Upper Cretaceous sediments of this section yield medium diverse and well-preserved calcareous nannofossil assemblages. A structural analysis of Upper Cretaceous calcareous nannofloras has revealed 30 nannofossil species. A revised zonatio...

calcareous nannofossil assemblages recovered from a long, continuous section have been described from the sarayan region in lut block in east iran. the marine upper cretaceous sediments of this section yield medium diverse and well-preserved calcareous nannofossil assemblages. a structural analysis of upper cretaceous calcareous nannofloras has revealed 30 nannofossil species. a revised zonatio...

in this study, calcareous nannofossils at the boundary between tirgan and sarcheshmeh formations at taherabad and mozduran sections have been studied. these sections are located in the eastern kopet-dagh basin. 22 nannoplankton species of 14 genera in taherabad section and 20 species of 14 genera in mozduran section were identified. according to the first occurrence of index species and fossil ...

Rare calcareous nannofossils from the Cape Roberts Project drillhole CRP-2A indicate that this area was episodically invaded by marginal oceanic surface waters during the late and late early Oligocene. These depauperate assemblages lack most of the biostratigraphic index fossils for the Oligocene, but do provide two datums that aid in constraining the age of the section: the last appearance dat...

a succession of late campanian- early maastrichtian is analyzed from gurpi formation with regard to the calcareous nannofossils. correlation matrix was applied for the first time to the entire nannofossil assemblage to reconstruct environmental conditions. a detailed quantitative calcareous nannofossil analyses is performed on samples in order to further investigate the climate events, and inte...

Erba et al. (Reports, 23 July 2010, p. 428) attributed calcareous nannofossil morphology and assemblage changes across Cretaceous Oceanic Anoxic Event 1a to the effects of surface ocean acidification. We argue that the quality of carbonate preservation in these sequences, the unsupported assumptions of the biotic response to acidity, and the absence of independent proxy estimates for ocean pH o...

A biostratigraphic study based on calcareous nannofossils was performed on the chalky limestone from the Abderaz Formation in the Mozduran section (Kopet Dagh basin, NE Iran). Semiquantitative estimates of total nannofossil and single species abundances showed that calcareous nannofossil assemblages are common and their preservation is good. In this study37species have been identified in chalky...