Climate events between 47.5 and 1 ka BP in glaciated terrain of the Ny-Alesund region, Arctic, using geomorphology and sedimentology of diversified morphological zones

Abstract

The Ny-Alesund region is characterised by diversified surface processes which carve the landscape and so exhibits variable and complex landforms. Extensive work has been carried out on climate change using various proxies however no much attention has been paid in understanding the climate events using geomorphological and sedimentological parameters. In the present paper sediment characteristics, AMS 14C dates and geomorphic features have been used for the reconstruction of palaeoclimate. On the basis of distribution of landforms, and sediments, this region has been classified into five morphological zones such as glacial (moraines GL), proglacial (lacustrine deposits LD), outwash plain (sandur deposits OWP), fluvial deposits (FD) and coastal cliff (CC). The geomorphic analysis and sedimentary parameters revealed that GL consists of unconsolidated, unstratified, massive, devoid of any sedimentary structures, coarse grained, matrix supported boulders, whereas OWP, LD, FD and CC are semi-consolidated, stratified, fine grained, layers of sand, silt, and clay with gravels and faint sedimentary structures. The sediments of CC and LD are very poorly sorted, very positively skewed, very leptokurtic, medium to fine sand, silt and clay. The sediment characteristics coded in the geomorphic features of various morphological zones explains that this region was carved and dominated by glaciers under cold climate at ice stages during 47.5, 38, 23, 18, 8.8, 6.l, 1 ka BP and paraglacial processes under warm climate at interglacial stages during 44, 27, 12, 10.5 ka BP. The poorly sorted sediments for all the morphological zones explain the fluctuating energy of the depositional environment and so the prevailing climate was not consistent and persistent for long period of time.