Modern Planktonic Foraminifera

Timing of Langhian bioevents in the Carpathian Foredeep and northern Pannonian Basin in relation to oceanographic, tectonic and climatic processes

“…Four dif fer ent datasets have been dis tin guished , each char ac ter izing spe cific lev els in the wa ter col umn: (1) data from Globigerinoides bulloides char ac ter ize sur face wa ters dur ing pe ri ods of en hanced pro duc tiv ity (prob a bly spring bloom; Schiebel et al, 1997); (2) data from Globigerinoides char ac terize sur face sum mer strat i fied wa ters (Reynolds and Thunell, 1985;Hemleben et al, 1989), (3) data from epifaunal Cibicidoides spp. re flect the qual ity of the bot tom wa ter (Kaiho, 1994;Murray, 2006); (4) pore wa ter chem is try in the sed i ment was doc u mented by iso to pic val ues from shal low infaunal Melonis spp.…”

Late Quaternary palaeoenvironmental changes in the Aegean Sea: interrelations and interactions between North and South Aegean Sea.

“…After washing and drying at 60 o C, the samples were sieved through 150 and 63 μm mesh. The >150 μm size fraction was split into aliquots, from which 300 specimens of planktonic foraminifera were picked, identified and counted following the taxonomic concept of Hemleben et al (1989). For palaeoenvironmental reconstructions, Q-mode and R-mode cluster analyses have been performed on the data set, after exclusion of rare species (< 2%) and grouping of species that have a discontinuous, scattered distribution at generic level.…”

“…In sub-assemblage IIB, the simultaneous presence of oligotrophic (G. ruber alba, G. ruber rosea, G. rubescens, G. trilobus/sacculifer group, O. universa and G. siphonifera) and eutrophic (G. bulloides, N. pachyderma, T. quinqueloba and G. glutinata) species certifies the seasonal contrast according to the available food supply, which characterizes this sub-assemblage. The factor of seasonality is also reinforced by the continuous presence (even in small amounts; 0.20-3.90%, average 2.05%) of G. glutinata, since this species can survive both in oligotrophic surface, and in more eutrophic waters by changing its diet from diatoms to crysophytes (Hemleben et al, 1989). Finally, in sub-assemblage IIC the significantly high percentages of the species belonging to the SPRUDTS group, and the presence of the species G. inflata and N. pachyderma (Hemleben et al, 1989; allow us to assess the role of water column stratification.…”

“…The factor of seasonality is also reinforced by the continuous presence (even in small amounts; 0.20-3.90%, average 2.05%) of G. glutinata, since this species can survive both in oligotrophic surface, and in more eutrophic waters by changing its diet from diatoms to crysophytes (Hemleben et al, 1989). Finally, in sub-assemblage IIC the significantly high percentages of the species belonging to the SPRUDTS group, and the presence of the species G. inflata and N. pachyderma (Hemleben et al, 1989; allow us to assess the role of water column stratification.  Biotope III (Assemblage Neogloboquadriniids): It contains 7 samples (SK21, SK34 and SK36-SK40) and represents the middle part of the core, which corresponds mostly to the transition from glacial to Holocene period.…”

“…During the deposition of sapropel, as well as before and after this, the species G. ruber rosea and G. trilobus play the dominant role in fauna. They occur close to the surface, where there are the maximum levels of solar radiation and specifically into the low fertility mixed layer, which charac-terizes a strong vertical stratification of surface waters during the summer months (Hemleben et al, 1989). Similarly, the other species of this group live above the thermocline in a warm and well stratified water column .…”