Paleoenvironments of a proglacial lake in Schirmacher Oasis, East Antarctica: Insights from quartz grain microtextures

Polish Polar Research

Mazumder Abhijit¹  Kar Ratan¹  Govil Pawan¹  Gayathri Narath Meethal²  Raghuram³ 

[1] Birbal Sahni Institute of Palaeosciences, 53 University Road, Lucknow – 226 007, India;Department of Marine Geology and Geophysics, School of Marine Sciences, Cochin University of Science and Technology, Cochin – 16, India;Polar Studies Division, Geological Survey of India, Faridabad, Haryana – 121 001, India;

关键词: Antarctica;    Dronning Maud Land Proglacial lake;    Holocene;    Quartz grains;    microtexture;    sand percentage;    CONISS Cluster Analysis;   

DOI  :  10.1515/popore-2017-0002

来源: DOAJ

【 摘 要 】

Eighteen sediment samples from a 36 cm long sediment core retrieved from a proglacial lake (namely P 11) situated in the Schirmacher Oasis, East Antarctica, were analysed for the study of quartz grain morphology and microtexture, along with sand percentage, to reconstruct the paleoenvironmental changes in the lake during the Holocene. The age of the core ranges from 3.3 ka BP to 13.9 ka BP. The quartz grain morphology and microtexture reveal significant evidences of glacial transport along with some eolian and aqueous activities. On the basis of predominance of these signatures and the zonation from CONISS Cluster Analysis on the percentages of characteristic grain morphology and microtextures, the entire core has been subdivided into three major zones. From the paleoenvironmental perspective, it can be concluded that there is an onset of interglacial period at the advent of Holocene (12.3 ka BP), which reigned until 5.3 ka BP and thereafter, again a glacial environment prevailed until 3.3 ka BP with some variations in-between. The results indicate probable alternative colder and less colder phases in the study area, which are also well supported by the respective sand percentages in the sediments.

【 授权许可】

Unknown