New insights into Southern Caucasian glacial-interglacial climate conditions inferred from Quaternary gastropod faunas

New insights into Southern Caucasian glacial-interglacial climate conditions inferred from Quaternary gastropod faunas

Dr. Christiane Richter¹, Dr. Daniel Wolf¹, Dipl.-Biol. Frank Walther², Dr. Stefan Meng³, Dr. Lilit Sahakyan^4, M. Sc. Tilmann Wolpert⁵, Prof. Dr. Markus Fuchs⁵, Prof. Dr. Michael Zech¹, Prof. Dr. Dominik Faust¹

¹Dresden University of Technology, Helmholtzstr. 10, 01069 Dresden, Germany

² University Hamburg, Centrum für Naturkunde, Martin-Luther-Platz 3, 20146 Hamburg, Germany

³ Ernst-Moritz-Arndt-University Greifswald, Friedrich-Ludwig-Jahn-Str. 17a, 17489 Greifswald, Germany

⁴ National Academy of Sciences of the Republic of Armenia, Baghramyan Ave. 24a, 0019 Yerevan,
  Armenia

⁵ Justus-Liebig-University Giessen, Senckenbergstr. 1, 35390 Gießen, Germany

We present our latest results  from gastropod analyses conducted on loess palaeosol sequences from northeast Armenia (Southern Caucasia) covering at least three glacial-interglacial cycles. The ecostratigraphy shows significant patterns of species composition related to the succession of pedocomplexes and loess, respectively. Pedocomplexes included species that can be associated with highgrass- to forest-steppe biomes, indicating increased humidity for these sections compared to loess layers. In contrast, loess layers that relate to glacial periods are associated with gastropod species of semidesert environments with shrub- and shortgrass-steppes, indicating semiarid to arid conditions. Furthermore, the loess deposits do not show any evidence for cold-adapted gastropod species. Therefore we suggest that average July temperatures in the study area were above 10°C, even during periods of loess deposition. We propose, that the limiting factor for bios during glacial periods was aridity, rather than temperature. In addition, we observe environmental differences between the various glacial times, with our results indicating a trend towards steadily increasing aridity in Southern Caucasia across the Middle to Late Pleistocene.