Chironomids in Quaternary permafrost deposits in the Siberian Arctic

Larisa Nazarova

doi:10.5324/cjcr.v0i25.1539

Abstract

Permafrost records, accessible at outcrops along the coast of Oyogos Yar at the NE-Siberian Dmitry Laptev Strait provided unique insights into the environmental history of Beringia during the last interglacial (Kienast et al. 2011). A paleontological study was carried out on the last interglacial (Kazantsevo, Eemian, Sangamoian, MIS 5) terrestrial and freshwater organism assemblages preserved in frozen deposits of a shallow paleo-lake outcropped at a permafrost cliff at Oyogos Yar (72.68°N; 143.53°E), the mainland coast of the NE-Siberian Dmitry Laptev Strait, Republic Yakutia, in the Russian Federation (Fig. 1). The Dmitry Laptev

Highlights

The majority of the taxa are indicators of temperate shallow lakes or littoral conditions that are associated with macrophytes
Smittia foliacea-type could be indicative of erosional processes or unstable lake level conditions (Cranston et al, 1983)
Brillia and Endochironomus albipennis-type often are associated with submerged wood and dead leaves (Cranston et al, 1983)

Summary

Introduction

The chironomid record indicates the presence of submerged coarse plant debris in the paleo-lake, most probably the remains of trees and shrubs. From a total of 50 chironomid head capsules, recovered from Eemian deposits, 16 taxa were identified (Table 1). The dominant taxa were Limnophyes, Smittia foliacea-type and the Psectrocladius sordidellus-type. The majority of the taxa are indicators of temperate shallow lakes or littoral conditions that are associated with macrophytes.

Results

Conclusion