caa a22 4500 475827635 CHVBK 20180406123833.0 cr unu---uuuuu 170329e20000901xx s 000 0 eng 10.1007/s005319900064 doi (NATIONALLICENCE)springer-10.1007/s005319900064 A computer-assisted thin-section study of Lake Baikal sediments: a tool for understanding sedimentary processes and deciphering their climatic signal [Elektronische Daten] [Pierre Francus, Eugene Karabanov] A freeze-drying technique for cutting thin-sections of soft sediments without disturbance is used to study several Lake Baikal sedimentary microstructures. Image analysis methodology is applied to selected thin-sections. This new technique provides quantification of the size, shape, orientation and packing of the objects forming the sedimentary structures. Sedimentary processes, which were previously poorly documented, have been identified, and others are better understood. Spheroidal lens-like pure aggregates of the diatom genus Synedra are found in hemipelagic sediments, providing a new insight into their traditional paleoecological interpretation. They are possibly related to a transportation mechanism from the littoral zone or to lacustrine snow. Laminae of Aulacoseira have also been recorded. Evidence of rapid sedimentation suggests they are due to massive algal blooms. The depositional mechanism that was suggested by other studies for explaining the laminations at the Buguldeika uplift is confirmed: the hemipelagic sedimentation is interrupted by terrigenous pulses due to discharge events. The sedimentation rate appears to be increasing during these pulses. Preliminary results from the Academician Ridge show stronger microbioturbation during cold periods. This observation strengthens the hypothesis of intense water circulation during colder times. Thin-section image analysis provides crucial information for deciphering lacustrine records and their regional and palaeoclimatic significance. Springer-Verlag Berlin Heidelberg, 2000 Key words Image analysis nationallicence Sedimentary structures nationallicence Thin-sections nationallicence Lake Baikal nationallicence Laminations nationallicence Diatoms nationallicence Paleoclimate nationallicence Francus Pierre Université Catholique de Louvain, Mercator, B-1348 Louvain-la-Neuve, Belgium, BE aut Karabanov Eugene Department of Geology, University of South Carolina, Columbia, SC 29208, USA, US aut https://doi.org/10.1007/s005319900064 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s005319900064 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Francus Pierre Université Catholique de Louvain, Mercator, B-1348 Louvain-la-Neuve, Belgium, BE aut NATIONALLICENCE 700 1- Karabanov Eugene Department of Geology, University of South Carolina, Columbia, SC 29208, USA, US aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer