Late Pleistocene and Holocene landscape evolution at Lake Paravani (Lesser Caucasus, Georgia)

Lake Paravani is located in the Republic of Georgia at an altitude of 2073 m on the volcanic Javakheti Plateau (Lesser Caucasus). Although first studies were conducted at the lake the last years, many questions remain unsolved regarding to the sedimentation pattern and the landscape evolution in general. Hence, we aim to deepen the understanding of landscape genesis during the Holocene and beyond. Therefore, a coring transect of eight cores was taken in the southern part of the lake and two of these sediment cores, ICE001 and ICE006, were analysed with respect to (i) landscape, vegetation and climate evolution since the Pleistocene, and (ii) their processes. By using an applied multi-proxy approach, sediment properties in terms of granulometry, geochemical composition, magnetic susceptibility, organic content, and palynology were analysed.

The results suggest high lake levels for the period from about 28 to 16 ka BP, inferring a cold and humid climate in the Lake Paravani basin. The landscape was covered by glaciers, which act as drivers for the prevailing physical weathering while sparse vegetation and poorly developed soils dominated around Lake Paravani. Since 16 ka BP, a declining lake level is identified, from which a significant increase in aridity is inferred while temperatures remain constantly low. The accompanying shift of facies into the sublittoral establishes variable depositional conditions at the site of borehole ICE001. For this reason, the transition from glacial to interglacial is poorly recorded. Early and middle Holocene deposits were eventually eroded during lake level fluctuations. A palaeobeach facies at approximately 4.5 ka BP displays low lake level and indicates high aridity. The period from 4.5 ka BP to present was characterized by rising lake level to recent conditions. Furthermore, increasing productivity within the lake, as shown by the total organic content, indicates warmer temperatures, and consequently increasing intensity of chemical weathering. In addition, vegetation cover established and soils developed.