First Multy-Proxy Studies Of High-Mountain Lakes In Armenia: Preliminary Results

Tatyana V Sapelko,Mikhail A Naumenko,Mikhail Yu Aleksandrin,Liana A Margaryan,Ivan G Gabrielyan,Artak S Piloyan,Dmitry V Sevastyanov,Anton V Terekhov,Vladimir R Boynagryan

doi:10.24057/2071-9388-2019-87

Abstract

Within the framework of the Russian-Armenian project “The Paleolimnological Aspect of Studying the Evolution of Ecosystems of High-Mountain Lakes of Russia and Armenia” in July-August 2018, we investigated four high-mountain lakes of Armenia. The research focuses on the lakes Kari, Umroi, Akna and Sev. All investigated lakes are located at the altitudes about 3000 m above sea level. We first time these lakes were investigated using a multi-proxy method that includes paleolimnological, geomorphological, hydrological, geochemical and biogeographic studies. The research offers the first statistical characteristics of lake depth distribution, water volume and other morphometrics. Lake sediments sequences and radiocarbon dates were received and analyzed for Armenian small lakes for the first time. We determined that all the studied lakes were formed during the Holocene. Sediments of Lake Kari were deposited in the last 4000 years, sediments of Lake Umroi – within the last 8000 years, while maximum thickness of sediments is around 1 m in both lakes. Hence, we assume low deposition rate in Armenian high-mountain lakes, however, it varied significantly in different periods of lake history.

Highlights

Almost all the data concerning the history of Armenian lakes are associated with the studies of Lake Sevan
In the Mid Holocene precipitation became higher by 28%, climate got to be milder, the water level in Lake Sevan rose and the forest vegetation spread over lake watershed
Lake sediments were sampled using Lake sediment thickness for all the Russian corer with 5 cm chamber diameter studied lakes is relatively low and cored from a platform mounted on a catamaran. successions length does not exceed 2 The corers consist of single 1 m length m

Summary

Introduction

Almost all the data concerning the history of Armenian lakes are associated with the studies of Lake Sevan. Evolution of this lake, the largest in Armenia, was reconstructed based on small outcrops of buried peat and archeological sites (Sayadyan 2000; Ollivier et al 2010; 2011; Joannin et al 2014). Reported Holocene radiocarbon ages were obtained either from Lake Sevan or on its watershed. In the Mid Holocene (between 7800 and 5100 cal BP) precipitation became higher by 28%, climate got to be milder, the water level in Lake Sevan rose and the forest vegetation spread over lake watershed. Around 5700 cal BP climate started to turn drier and after 5100 cal BP arid conditions are dominating

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Conclusion